Bizarre Journey to the Outer Solar System DOCUMENTARY BOXSET These Planets Continue to Mystify Us

Until Voyager reached the Neptunian

system

, it was the least understood of all the

planets

invisible to the naked eye. Neptune was a world hidden from view even through the most powerful of telescopes. It looked like nothing more than a blurry ball of blue and green. The largest planet in the

solar

system

in volume and the third in mass. From afar we knew nothing about its atmosphere or structure and had only vaguely observed two of the moons in its orbit, Triton and Narid. This was a planet that had stayed very firmly in its orbit. darkness a distant world that had held tightly to its secrets for more than 140 years even the discovery of Neptune took place in darkness the last of the

planets

to be discovered is the only one whose existence we predicted before it was observed by the eye human for centuries we stared at it without knowing what we were looking at almost certainly Galileo was the first human being to appear directly on Neptune during a series of observations in late 1612 to early 1613 the data he plotted with his newcomer The invented telescope led him to believe that it was a fixed star in the night sky, not a planet.

Over the next 200 years, many astronomers must have fixed their gaze on this faint star, unaware of the significance of its bluish light, but aware of the first hint of its true nature. would not appear in an eyepiece but in a set of astronomical tables. In 1821 the French astronomer Alexi Bvar published Astronomical Table, a set of tables that predict the orbits of the three

outer

planets Jupiter, Saturn and Uranus based on the laws of motion and universal gravitation of Newton on the In the following years, Bal's theoretical work would be tested against the movements of the night sky and his painstaking calculations were rewarded with confirmation that his actual observations of the movements of Jupiter and Saturn matched his mathematical predictions;

However, Uranus refused to behave as docile as The movement of the then most distant planet deviated substantially from the trajectory predicted by BV and this led him to make a wild suggestion: either Newton was wrong or perhaps there was a planet still undiscovered lurking in the darkness distorting the passage of Uranus through its gravitational interaction, a flurry of astronomers raced to find the hidden planet, the ultimate prize for any stargazer. As a bitter race began between the British and French to predict the planet's location on the British side of the Channel, Cornish astronomer and mathematician John Couch Adams became obsessed with the BV hypothesis and was convinced that he could use nothing but pencil and paper to determine the size, position and orbit of this Hidden World in September 1845.

Adams had at least partially completed his calculations, but unbeknownst to him, almost simultaneously the French mathematician Urbanler was completing his in Paris. complex calculations of the trajectory of Uranus and The elusive eighth planet in the summer of 1846 ler had played his hand and announced to the academy on August 31 that he had calculated a predicted location for the lost plan, revealing his work just 2 days before Adams. He secretly sent his own prediction in a letter to the Royal Grenwich Observatory for verification in what must be one of the closest races in scientific history. Ler involved the Berlin observatory in the search for his planet and at 12:15 p.m. on the 24th.

In September 1846, Yan Galla, with the help of his assistant Einrich Dar, looked through his refracting telescope and became the first person to knowingly observe the eighth and most distant planet in the

solar

system. A planet that had taken decades to locate was found in less than an hour and within a degree of the position that L had calculated, even today the exact credit for the discovery of Neptune is still in dispute, but the winner takes all. of astronomical discovery is Leber who history records as the discoverer of Neptune, the man who discovered a planet with the tip of his pen, another 143 years passed before we visited Leber's planet and witnessed a dynamic, violent world and volatile when Voyager approached and began returning a precious set of images that remain to this day our only close-up record of This planetary system initially passed by Neptune's third largest moon.

Voyager captured our only image of this distant world traveling in its wildly eccentric orbit around the planet, but it was images of Neptune itself that became increasingly striking painted on the planet's surface. The Voyager planet revealed banks of methane clouds that were being whipped by high-altitude winds at speeds of more than 2,000 km hour, at least five times stronger than the most powerful winds ever measured on Earth. These were the highest wind speeds we had witnessed anywhere in the world. solar system it wasn't just violent winds that we saw through the traveler's eyes, large hurricane-like storms could be seen moving across its surface, the largest being an Earth-sized storm system similar to the Great Red Spot on Jupiter, which became known as the Great Dark Spot Voyager took multiple images of this vast storm system as it sped past the planet skimming the cloud tops of the North Pole from a distance of just 4,400 kilometers when it reached its deepest point. nearby on August 25, 1989.

No one had expected such a massive magnitude. Storms were brewing so far from the Sun, but just 5 years later, with the Hubble telescope up and running, we looked towards Neptune and discovered that the Great Dark Spot had disappeared, unlike the giant storms on Jupiter we have witnessed for centuries. It seems that the weather on Neptune is much more transient, with major events coming and going in the space of a few years. The intense weather systems we witness on Neptune remain a tantalizing enigma: the planet is on average 50% farther from the Sun than Uranus and receives only 40% of the sunlight reaching its sister world and the surface temperatures of both planets are equally intensely cold.

In fact, the temperature of Neptune's

outer

atmosphere is one of the coldest places in the solar system, with temperatures at its cloud tops measuring around 220°C orbiting as far away as the solar system's distant icy reaches explains. the mildness of Uranus' climate, but why would Neptune be so active even further away from the Sun? The answer we believe lies in a mysterious and powerful source of heat that they have detected coming from the depths of the planet, all planets, including Uranus and Neptune, have some residual heat locked deep within their interior and much of this It is the thermal energy left over from the endless collisions of their creation, as well as the heat released by radioactive planets. disintegration of certain elements in the nucleus;

However, so far away, Uranus has rapidly lost this heat and today radiates only 1.1 times the energy it receives from the Sun, so the heat it radiates from its core is too small to drive any kind of dynamic climate system through of the. Its atmosphere Neptune appears to have a much warmer heart and Voyager was able to reveal that the most distant planet radiates 2.61 times more energy than it receives from the Sun. It is these unexpectedly high temperatures that help explain the violent storms we see in Its atmosphere as heat makes its way from the planet's core into space stirs up the entire atmosphere creating winds of extreme ferocity and once they start there is little that can stop them.

Neptune, like Uranus, is an ice giant, a planet composed of a rocky core and a mantle made up of water, ammonia and methane ices surrounded by a cold gaseous atmosphere. With no solid surface on the planet, there are no mountains or continents to break the flow of atmospheric gases, so winds can buffet the planet. The planet is gaining speed until it is literally going supersonic. All of this helps give us a reason for Neptune's extreme weather, but not an explanation. Voyager 2 couldn't reveal why Neptune and Uranus are so different and we still don't know what it is. about these planets, their formation left Neptune with much more residual heat, making it the more active of the two.

Neptune's active atmosphere wasn't the only surprise that Voyager returned to us with images from its two-camera system in vibrant and vivid detail, the images also revealed that the solar system is home to not one but two blue planets. Neptune is a bright blue world, but without liquid water on its surface, we know that the origin of this color cannot be the same as here on Earth this deep cobalt color must be. produced by something else in Neptune's atmosphere and Voyager provided the answer using its onboard spectrometer. Voyager was able to measure the composition of Neptune's atmosphere for the first time and discovered that it was composed of 80% hydrogen, 18.5% helium and 1.5% methane.

By far the smallest component, but this is the key to understanding Neptune's blue hue. Sunlight contains all the colors of the rainbow, but when it hits the surface of a planet it interacts in different ways depending on the molecules it encounters. On Earth, the water that covers our planet absorbs all the red light from sunlight, so when the sun hits the surface, only blue is reflected. The same happens with all the plants on our planet, chlorophyll absorbs blue and red light, so only green is reflected in Neptune, there is no water that turns the planet blue, but it is methane that absorbs the light The sun's red light is dim and distant, reflecting blue light in the darkness, but things are not as simple as they seem.

Appearing for the first time Uranus is also a blue world, but a little paler and greener in tone compared to its more distant brother, and yet Uranus also has methane in its atmosphere; in fact, it has a bit more, so Uranus, not Neptune, should be a darker shade of blue. Because? It's wonderful, we still don't know. Voyager looked for other components in Neptune's atmosphere that could explain the deeper blue, but found nothing that could explain the discrepancy, so for now the many differences between these two worlds remain a mystery after more than 12 years. Travel Voyager 2 completed its great tour of the solar system, a small explorer that left Earth and traveled through 7 billion kilometers of space on a unique and extraordinary

journey

to explore all the outer worlds of the Solar System Jupiter Saturn Uranus and Neptune, but before beginning its long and lonely

journey

into the darkness of interstellar space it had one more brief encounter left on its itinerary, while in the Neptunian system Voyager had made a host of discoveries, including the detection of a system of faint rings and confirmation of six new moons in orbit, but in those final hours of close contact as it flew across the planet's North Pole, mission scientists at JPL had ordered the spacecraft to make one last Intrepid maneuver: a close flyby of Neptune's giant moon Triton just 5 hours later. almost touching the cloud tops of Neptune Voyager traveled 40,000 kilometers from the Neptunian Moon and obtained the first photographs of this strange and distant world.

British astronomer William Lassle first saw Triton on October 10, 1846, just 17 days after the discovery of Neptune as Astronomers clamored to observe the newly identified planet. It was Lassle, with his homemade telescope, who first noticed the satellite, although it was not officially named until many years later. Triton would remain the only known satellite of Neptune for over 100 years until the discovery of Narad by Gerard Kyper. More of it later, in 1949, when Voyager returned the first images of this distant Moon, it immediately became clear that, like Neptune, Triton was much more active than we had ever imagined, here in the outer reaches.

Far away in space, was the seventh largest moon in the solar system. Far from being a frozen inactive rock, it was a geologically active world with characteristics unlike anything we had imagined, capable of imaging only 40% of its surface due to the fact that most of the northern hemisphere was in darkness. Voyager revealed that Triton had a sparsely packed exterior. With a strange network of ridges and valleys covering its entire surface, including a region in the Western Hemisphere that yielded the Canter Loop terrain due to its striking similarity to the skin of a melon, all of this evidence pointed to the fact that the surface Triton was young. not as battered and old as that of our moon, a surface that, although it had been recorded by the travelers' instruments as one of the coldest places in the solar system at 235° C, seemed to be resurfacing due to the active volcanism that was taking place. producing throughout theplanet, but this was not volcanism as we understand it here on Earth, there is no molten rock beneath the surface of Triton, this is an ice world with a surface covered by a frozen mixture of nitrogen, water, ice and carbon dioxide. carbon.

Any volcano that exists here would be a cryovolcano. erupting water, ammonia and methane from beneath the surface, cryomagma that would immediately solidify in the extremely low surface temperatures, and as Voyager appeared closer to Triton's surface, it captured a series of images of the south polar region that They seemed to provide evidence of such geological activity lurking among the flat volcanic plains and rift valleys was a set of distinctive features that immediately caught the eye. Scattered across the surface were what appeared to be at least 50 dark columns. Voyager was traveling so fast and so far from the Moon.

We weren't able to get close-ups of these intriguing columns, but we are sure that they are evidence of ice geers and that dark streaks of dust are deposited on the surface by the eruption of these geers, according to planetary scientist Noah Hammond. It was a big surprise to see active gas on Triton shooting 8 kilometers into the air and we think these geas could be forming as a result of nitrogen ice being vaporized by the sun, both gases that Voyager 2 observed, which are currently explode are concentrated in the warmest part of Triton, where the sunlight hits the hardest and when the sunlight passes through the nitrogen ice, it begins to convert that nitrogen ice back into gas and that gas builds up and It builds up until it has enough energy to break the ice and lift dust into the atmosphere.

Further analysis of the images suggested that at least four of these geese were active at the time of the trip. The flight passed through clouds of ice and dust 8 kilometers high in the thin Neptunian atmosphere before falling back to the surface more than 100 kilometers downwind. Perhaps most surprising is that we have been able to hypothesize the mechanism underlying them, the key to understanding why this wonderful geological activity occurs in the most unlikely place appears to involve its location on the surface of Triton, according to data from images returned by Voyager 2, it appears that gas tends to erupt in In the most sunlit part of Triton's surface, from a distance of 4.5 billion kilometers, the Sun's rays are weak and the amount of energy thermal landing on the surface is low, but combined with the specific chemistry of Triton's surface, the Sun's effect can still be dramatic.

What appears to be happening is that sunlight falling on the thin layer of nitrogen ice covering Triton is penetrating the surface and heating a layer of darker methane particles. One meter below the surface, methane acts as an underground greenhouse gas by trapping heat below the surface. and radiate that heat back through the frozen nitrogen, although this mechanism creates a temperature difference of only 4° C between the ambient surface temperature and that of the warmer interior, this difference is enough to melt the frozen nitrogen and create gas pockets underneath. Nitrogen ice, that gas, is kept under pressure and builds up until it eventually breaks through the nitrogen ice, creating Triton's gers and carrying the dark ice particles up to 8 kilometers into the sky, although the faint sunlight is strong enough to feed.

Triton's gas is simply too weak to have driven the other geological processes that have created the network of valleys and cracks we see across the surface. It seems that something in Triton's past must have heated the moon enough to drastically alter its terrain and a possible clue. The source of that ancient heat can be found in the oddity of Triton's orbit - unlike any other large moon in the solar system, Triton orbits in the opposite direction to the spin of the planet that travels around Neptune in its neatly closed orbit with the same side looking. inward at all times Triton orbits clockwise, while Neptune rotates on its axis every 16.11 hours counterclockwise.

Such dissonance between planet and satellite suggests that it is highly unlikely that Triton and Neptune simultaneously formed a planet-moon system formed from an identical system. A cloud of gas and dust that collapses at the same time would tend to spin and orbit in the same direction as the spin of the initial dust cloud, just like the overwhelming majority of moons we see in the solar system today, so The most likely explanation is that Triton joined Neptune much later as a visitor from the Neptunian system which, unlike Voyager, never left Uranus. We don't know for sure the deep history of Triton, but all the evidence from its orbit and surface features point to the possibility that long ago Triton was not a Moon.

To understand where it might have come from we need to look beyond the system. Neptunian and look beyond into the darkness. It was relatively recently that we confirmed the existence of a region of the solar system now known as the Kyper belt. a diss of millions of objects that extends from the orbit of Neptune to at least 50 AU from the Sun, similar in structure to the asteroid belt but much larger in scale, we had long speculated that such a region could exist, but it was not until The discovery of an icy object known as 15760 Albian in 1992 allowed us to gather a body of evidence.

The discovery of this region was a turning point in our knowledge of our solar system, according to Alan Stern of the New Horizons mission. The Kyer belt was so revolutionary because, because it is so far from the Sun, the temperatures are almost absolute zero, so everything is so well preserved that it is an archaeological dig, if you will, in the early history of our solar system, so it is a country of scientific wonders and you put everything together redraw the map and put it in our place about who is the Oddball now it is not Pluto, it is the Earth or Jupiter that is the Oddball and then place this museum piece in the solar system where everything is so well preserved that I can't think of We have made a biggest discovery that has reshaped our thinking so profoundly in all the decades of space exploration.

Albian was the first trans-Neptunian object identified since the discovery of Pluto on its moon Sharon and this discovery launched an avalanche of additional revelations that If we now put the number of objects identified in the Kyer Bel region at around 2,400, we believe there are at least 100,000 objects over 100 km wide in the Kyer Belt, like the asteroid belt, this scattered region of debris is composed of remnants of our solar system. formation of systems, but while the asteroid belt is a disk of rock fragments, we believe that the Kyper belt is made up of icy objects with water methane and ammonia as the main ingredients and it is that list of ingredients that takes us back to Triton and his strange story. now that perhaps only Triton grew in the Kyer belt among the millions of other frozen chunks of water, ammonia and methane that surrounded the sun before something like a collision disturbed its orbit and threw it inward, torn from the Kyer belt , Triton would be captured by Neptune's gravitational pull and trapped forever in its strange orbit around the blue planet, today Triton orbits in a nice regular circle around Neptune, a bit like the way our moon orbits the Earth, but to begin with this newly captured satellite would almost certainly have been in a chaotic orbit looking beyond the planet, it would have started along a wide elliptical path around Neptune, taking it from very far away to get closer at each revolution, this would have meant that as Triton orbited Neptune, the gravitational pull would constantly change, stretching and crushing the moon just as Jupiter does with IO today, with the result that the friction of these tidal forces would have heated the interior of Triton creating much more activity than the erupting gas we see today through this process of tidal heating of the ancient ice interior.

It would have become molten and volatile exploding through cracks and faults in the lunar crust creating the irregular surface we see today Over time as the orbit adjusts to a more regular circular path, friction reduced heating decreased, so that what we are left with is a frozen, icy Moon spinning counterclockwise around its Planet the subtle scars of its early life written on its surface All that remains today of that dramatic and violent past are the Geyers driven by the faint Sunlight painting dark streaks across the now-dormant surface As Voyager 2 sped away from Triton and Neptune at more than 60,000 km/h, the planetary exploration phase of this extraordinary mission finally came to an end.

His exploration would

continue

even beyond the furthest reaches of our solar system and extend to the unknown depths of interstellar space, but his time as a planetary explorer was over, a small spaceship built with a thousand human hands had illuminated the darkness revealing the secrets of worlds that had been hidden in the night for more than 4 billion years and we have not yet returned, but as Neptune and Uranus have once again fallen into the distance, seen only through the lenses of our most powerful telescopes , another even more distant world was out there awaiting our first arrival.

On the night of January 23, 1930, a young 23-year-old researcher at the Lowel Observatory in Flagstaff, Arizona, took an image of the night sky using a 13-inch astrograph. , a telescope designed for the sole purpose of astrophotography. Clyde Tomore had been at the observatory for just over a year when he took the image, one of hundreds he had captured. During the previous months, an enthusiastic amateur astronomer, he had landed this first job after sending a series of drawings he had made of Jupiter and Mars using telescopes he had built at home every night at Lowel's tomb and performed the same task using the astrograph to photograph. a precise section of the sky that he would then re-image a few nights later, the task was a bit laborious but its purpose was profound because, hidden within almost identical images, Tombo was on the hunt for a new world, the enigmatic Planet , unless we think a lot.

Our intellects are confined to the surface of the Earth after sunset. Beyond the cities, the universe seems a destination for the imagination, even if it is separated by a seemingly insurmountable gulf. This may be true for stars, but it is not true for planets. There are times when Mars, Venus, Jupiter and Saturn dominate the sky, bright lights that change position each night against the fixed stars that catch our attention, even if we are not sure what we are looking at, the distances are still enormous for us. terrestrial standards, but despite appearances, the gulf is certainly not unsalvageable. for we have visited all these planets and taken our first steps into the outer reaches of the solar system Beyond and yet the wandering lights in the darkness still feel separate from Human Affairs and the time and effort we have devoted to visiting them might seem However, to be an indulgence, this assumption is deeply erroneous, the solar system is one system, the sun and the eight major planets and the countless billions of minor planets, moons, asteroids, comets and chunks of ice and ungraded rock were formed in half the time and

continue

.

To evolve as one, we rarely notice the dynamic and interconnected nature of our system, although asteroid impacts on our planet are not that rare. The Chelyabinsk impact in February 2013 injured 1,500 people when a 12,000-ton asteroid broke up as it entered Earth's atmosphere at 60 degrees. times the speed of sound and the Tunguska air explosion in Siberia in 1908 leveled 800 square miles of forest in an explosion comparable to that of the most powerful hydrogen bomb ever tested on the surface of the Moon Bears, testimony to a record of violence and destruction from the skies that the Earth has also endured, but the relentless erasure of craters by erosion and our good fortune that there have been no major impacts in recorded human history are the reason for our misguided sense of isolation from the Heavens, the interdependent nature of the solar system has become more evident as we begin to understand its history, it is tempting to imagine that the physical arrangement of the planets is a fossilized remnant of primordial patterns in the dust cloud that collapses around the newly formed planets. lit, made 4.6 billion agoof years, but our exploration of the planets along with increasingly powerful computer simulations of the evolution of the solar system has revealed that this is not the case, planetary orbits are prone to instability, especially in the early years.

When our solar system was young, the details of precisely how planetary orbits have shifted are still unclear, but we now suspect that Mercury, the innermost planet, began life much further away and was deflected inward to its current location. scorched orbit. Jupiter and Saturn may have moved inward shortly after their formation before reversing course and retreating, but not before affecting the distribution. of the material from which Mars and Earth would later form around the time life began on Earth, Neptune and Uranus may have been flung out, disturbing the orbits of billions of smaller objects far from the Sun, The record of this era of unprecedented violence known as The Late Heavy Bombardment is written on the marked surface of the Moon, most likely formed in an interplanetary collision between Earth and a planet the size of Mars 4.5 billion years ago.

The planets are like snowflakes. The detail of its structure. His composition. The size. Spin and climate are a frozen record of your past. An understanding of the planets beyond Earth is therefore a prerequisite for understanding our home world and that, in turn, is a prerequisite for understanding ourselves. ourselves. Earth is unique in the solar system because it is a planet with a complex ecosystem, the Genesis and subsequent evolution of life on Earth over 4 billion years required planetary features that are necessarily linked to the evolution of the system as a whole. . There had to be liquid water on the surface of the surge and much of this water was delivered after the formation of the Earth by water ice. rich asteroids and comets possibly deflected inward from the outer solar system by Jupiter these rivers, seas and lakes of extraterrestrial origin had to persist for the better part of 4 billion years, requiring a stable atmosphere to maintain temperatures and pressures of the surface within a limited range of 4 billion years is a long time, about a third of the age of the universe, the sun has shone 25% since the Earth formed, making the stability of our environment be even more difficult to understand in a chaotic system of planets around an evolving star.

With life-sustaining properties and the remarkable stability that Earth has enjoyed for billions of years may be extremely unusual, the study of our sister worlds, Mars and Venus, has proven instructive in understanding how fortunate we may have been and how delicate our position might be today. A billion years ago, when life began on Earth, Mars was also Earth-like, having oceans and rivers, active geology and complex surface chemistry, the ingredients of life, one of the fleet's primary goals. of spacecraft currently orbiting and exploring the surface of Mars is to search for evidence of past or even present life and understand why the red planet transformed from a potential Eden at the dawn of the solar system to the icy desert world we observe today.

The story is complex, but one of the most important differences between the two worlds is that Mars is only one-tenth the mass of Earth, too small to retain its internal heat, protective magnetic field, and atmosphere for long. more than a billion years after its formation, but Mars formed in a similar region of the solar system to Earth and Venus so why is it so small? The answer may lie in the rapidly changing orbits of Jupiter and Saturn early in the history of the Solar System. The history of Venus is perhaps even more puzzling, in part because of the immense difficulty of exploring.

The planet Venus is often described as a vision of hell. Surface temperatures are high enough to melt lead and atmospheric pressure is 90 times greater than on Earth, raindrops of sulfuric acid fall from its clouds, and yet long ago Venus may also have been Earth-like, perhaps there once was. Venusians before a runaway greenhouse effect took hold and began destroying Venus's temperate climate about 2.5 billion years ago. Although this date is very uncertain, taken together, the histories of the three large terrestrial planets are healthy, if an astronomer If an alien were to observe our solar system from afar, they would classify Mars, Earth and Venus as potentially living worlds orbiting within the so-called habitable zone around the Sun, the region within which, if atmospheric conditions are suitable, liquid water can exist.

On the planet's surface, all three worlds may have once been habitable and all three worlds may have once supported life, but now only Earth supports a complex ecosystem, much less a civilization that understands why Mars and Venus diverged so significantly from Earth over the past 4 billion years will provide great insight into the fragility of the worlds and perhaps suggest whether our Good Fortune itself is almost impossible to understand or simply scandalous. The planets change ours could change in Any time a stray comet from the Kyper belt frozen beyond the orbit of Neptune could end our history we could also end ourselves the study of Venus could help us avoid one of the ways we could destroy our civilization because we shows what greenhouse gases can do to the world.

I think one of the reasons anthropogenic climate change is so difficult for a certain type of person to accept is that atmospheres seem ethereal and tenuous and unable to trap enough heat to significantly change temperatures on a planet for those people. I suggest traveling to Venus, where they will be crushed, boiled and dissolved on the surface of Earth's twin, exploring the planets later. It is not an Indulgence. If we want to know how we came to be here, we need to understand the stories of the planet where we were born and the system where we were born.

We are children of the Earth and also Children of the solar system. Understanding Our history is important because it puts our existence in context. The more we learn about the events that led to the emergence of humans on this planet just about 100,000 years ago, the more we are forced to marvel at the improbability of everything we needed. Jupiter and comets and asteroids and countless collisions and mergers and near-catastrophes dating back 4.6 billion years. There are valid objections to this way of thinking. It is an objective fact that we are here and our future should be our main concern.

That may be so, but. I maintain that a deeper understanding of the evolution of the planets is essential to our continued prosperity and existence. In this case, the threat of catastrophic climate change is an obvious example, but there are many other reasons why knowledge is important. There is feedback in human affairs. The collective state of mind affects the decisions we make; to limit our imagination to the surface of the Earth is to ignore both our immense good fortune and the fragility of our position. I believe that a broader understanding of both will help ensure a safer and more prosperous future Earth.

Located just 150 million kilometers from the Sun, neither too hot nor too cold, with surface temperatures ranging between -88 and + 58° C, this goldilocks place has created a climatic stability that, despite the best efforts of ice ages and impacts, has allowed life to maintain an unbroken chain for almost 4 billion years and yet we know for certain that our sun cannot last, since all the stars in the universe are far from be static. Stars have life cycles of their own and eventually the hydrogen fuel that powers the core reactions within a star will begin to run out and the star will enter the final phases of its life.

It will expand, cool and change color to become a red giant. Small stars like Har Son will die a relatively peaceful and beautiful death that will see them pass through a planet. nebula phase to become a white dwarf that will cool over time to leave a brown dwarf. Life on Earth has thrived during the intervening years of our Sun, but these optimal conditions are declining at first, the changes will be invisible, but within a billion years they will be Obviously for any life forms left on the planet, a immense Sun that fills the sky will warm and transform and the Earth that shines on the sun is both the giver and the taker of life on our planet.

It is one of the great paradoxes of the universe that as the life of a star like ours begins to change its size and its luminosity will increase, an increase in luminosity of just 10% will cause the average surface temperature of the Earth will increase to 47° C instead of the 15° C it is today. The effect of this increase in temperature is manifested in the lifting of large amounts of water vapor from the oceans to the atmosphere, creating a greenhouse effect that could get out of control. quickly and rapidly, evaporating ions from the ocean and skyrocketing surface temperatures, explains astrobiologist David Grinspoon.

The greenhouse effect is the name we give to the physical process by which the planets heat up through the interaction of their atmospheres and solar radiation. Basically, solar radiation comes in what we call visible wavelengths, mainly its wavelengths that We can see and most atmospheric gases are very transparent to visible radiation, so sunlight passes practically unobstructed through an atmosphere and reaches the surface of a planet, then the surface of the planet radiates that radiation in infrared. because the planets are much colder than the Sun and that means that they radiate at much longer wavelengths, what we call infrared or heat radiation, that infrared radiation does not pass through the atmosphere so easily some of the atmospheric gases, which we call greenhouse gases, they block infrared radiation and therefore the more greenhouse gases there are in a planet's atmosphere, the harder it will be for surface radiation to return to space and the warmer the planet will become.

Estimates of the time scale on which we will see our oceans disappear en masse will be heavily influenced by a multitude of factors, but there is less doubt that when our planet turns 8 billion years old in 3.5 billion years, the end will be within reach. Seen, with temperatures above 1,000 °C, life will have long disappeared from a surface that is beginning to melt under the burning Sun, moving even more. Later in the future, the outlook becomes bleaker as the Sun enters old age, growing into a red giant that will envelop the Earth within its expanding, moonless, lifeless and perhaps diminished atmosphere. to its inner core.

Our planet and the civilizations it once housed will be nothing more than a distant Memory etched in the atoms that made us all as they are scattered across the cosmos for planet Earth. The clock is ticking and time is slowly running out, but ours is far from the only world to enjoy its moment in the sun throughout the history of our history. solar system that stretches deep into its ancient past and stretches into its future we see stories of worlds in a constant battle with our ever-changing star near ancient worlds like mercury that long ago lost their fight with the sun mock the views of Earth and what might have been further away and even hotter, the circles of Venus shrouded in a suffocating blanket of clouds and even beyond Earth, Mars lies cold and arid.

Beyond these Suns, their frozen worlds wait huddled in perpetual hibernation anticipating the moment when the Sun's warmth reaches them. far enough away with enough heat to trigger a first spring, that day mountains of ice will melt, rivers of water will flow and where before there was only desolation in the distant future on planets once frozen and lifeless, we might find a place that looks like Much like home, the history of our solar system is not as we once thought it was eternal and unchanging, but rather a place of endless transformation, it is a narrative that repeats itself with a predictable rhythm as a world passes, another comes to light, only one planet has. maintain stability for almost the entire life of the solar system the Earth has remained habitable for at least 4 billion years while changes have occurred around it which makes the Earth so fortunate compared to all its terrestrial brothers to respond tothat question that we need to look not only at our planet but at the entire solar system, going back to the very beginning, during the first million years after its birth, there were no terrestrial worlds to see the sun rise and there were no days, no nights, No circular tracks around it Instead of surrounding our child star there was a large cloud of dust and gas, a small fraction of the material left over from the formation of the sun, this swirling cloud would one day coalesce to form the various planets of the solar system and many other smaller bodies. but at this time, 4.7 billion years ago, there was nothing but tiny specks of dust reflecting light from our slow-growing star, only a large amount of empty time would allow enough of this gas and dust to be trapped. and group randomly forming the smallest seeds.

Most of these seeds would hardly have a chance to grow if they were crushed and returned to the immense dust devil from which they emerged, only a few would grow large enough and survive long enough to capture and condense more cloud, slowly increasing their mass. and density, we still do not fully understand the process by which grains of dust no thicker than a human hair can accumulate to become rocky objects the size of a car, and so far there is no model to explain this part of the evolution of a planet, but which one? What we do know is that once that disk of gas and dust becomes populated with clumps of rock that exceed the meter-sized barrier of flesh, a powerful force comes into play to drive the process.

These newly formed planetesimals are large enough to allow for large sculpture. thousands and thousands of these objects live and die colliding and merging under the increasing gravitational forces of attraction and until finally only a few emerge as planetary embryos. moon-sized bodies known as protoplanets in the violent final stages of the planetary birth process these protoplanets spin in crowded orbits and many are destroyed they return to the dust of their origins, but occasionally when a collision brings two or more of these giant objects together the size of this mass of rock becomes large enough for gravity to pull it in from all sides creating a newly formed sphere Fe of rock a new world at that moment a planet is born each of the terrestrial planets in our solar system born this way are the survivors of a process that destroys many more worlds than it ever created and that left only four rocky planets, starting closest to the Sun with Mercury, then Venus the Earth and finally the most distant world, the cold and dead of M STS, today these four worlds.

They all look very different and yet they were all created the same way, composed of the same ingredients and orbiting the same star, so why did they end up so different from each other and with such markedly different environments and what makes this place, Earth, is so unique? Just one of the rocks on which life has flourished to understand that we have to look deep into the past of our solar system to explore the unique history of each of the planets through amazing feats of human engineering over thousands of years. of millions of kilometers and in environments of unknown and unimaginable extremes, reaching the smallest planet in the solar system is not at all easy to pass by the Sun at a distance of only 46 million kilometers at the closest point of its orbit Mercury is a planet that Not only is it deeply held down by the gravity of our massive star, but it also moves at an average orbital speed of 48 km/s, by far the fastest orbiting planet in the solar system and far surpassing Earth, plus slowly. 30 km/s needs to turn that fast, otherwise it would have.

It fell into the Sun's Embrace a long time ago, but the combination of its speed and position make it a planet that is immensely difficult to approach and even more difficult to orbit. To do this, you must travel fast enough to catch up with Mercury. but not so fast that we couldn't slow down somehow to avoid a precipitous descent towards the Sun and that challenge has meant that until relatively recently it was the least explored of all the terrestrial planets for many decades, our first and only close up view of the innermost Rock. The Sun's orbit came from the Mariner T spacecraft when on three separate occasions in 1974 and 1975 it briefly passed near Mercury.

This was the first spacecraft to use another planet to launch onto a different flight path using a fly from Venus to double its trajectory. to allow it to enter an orbit that would bring it close enough to Mercury to photograph it up close dressed in protection to ensure it could survive the intense solar radiation and immense temperature extremes. Marin 10 was able to send back the first detailed images of Mercury while flying just over 200 miles above its surface, passing by the same side of Mercury each time, so it was only able to map 40 to 45% of Mercury's surface.

The spacecraft took more than 2,800 photographs giving us views never seen before. of the planet's moon-like cratered surface, a surface that we have never before been able to fully resolve by Earth-based observation. Despite the beauty of the photographs taken, it wasn't the Marin 10 images that really surprised us, it was the data the probe collected related to Mercury's geology, which pointed to a much more surprising history of the planet than previously imagined. It seemed that Mercury was far from simply A scorched-shell navy was able to detect the remains of an atmosphere composed primarily of helium, as well as a magnetic field and a large iron-rich core, opening a mystery that would remain unexplored for another 30 years as it passed. by Mercury for the last time.

On March 16, 1975, the transmitters were turned off and their contact with Earth was silenced. Mission complete. Mariner 10 began a solitary orbit around the Sun that, as far as we know, continues to this day. At first glance, many things about Mercury are simply not understood. Strictly speaking, during its 88-day orbit around the Sun, it travels in a twisted elliptical orbit, meaning it can be as far from the Sun as 70 million kilometers, but occasionally as close as 46 million kilometers. This is by far the most irregular orbit of all. planets, but that's not the end of Mercury's weirdness, midday temperatures can rise to 430° C on the surface, but at night, because it is a small planet and has no atmosphere, temperatures drop to - 170° C, giving it the largest temperature swing of any known body in the solar system Its rotation is also unusual Gravitationally locked to the sun in what is known as a 3:2 spin orbital resonance, this means that the planet rotates precisely three times on its axis for every two orbits, which in turn means that its day is twice as long as its year, in effect, you could travel on its surface at a walking pace and keep the Sun at the same point in the sky as you walk through the Eternal Twilight, as planetary scientist Nancy Shabo explains, a day on Mercury is not like a day on Earth.

It has a very unusual orbit, it has to circle the Sun twice to have a full C solar day. on the planet where the sun passes directly from top to top and this actually takes 176 Earth days due to the orbit of the planet. They are places on the surface of Mercury where a hypothetical observer could see the sun, 2 and a half times larger in the sky, appear and set twice during a Mercury day, rise and then arc across the sky, stop and retreats towards the ascending horizon. it stops again and finally restarts its journey towards the western horizon.

Most of Mercury's anomalies can be explained by the orbital mechanics of its journey around the Sun, except for the strange elliptical orbit that takes it along an elongated, oval-shaped course that this irregularity has. baffled astronomers for centuries and hinted at an ancient planet that was very different from the Mercury we see today To really begin to understand the history of Mercury, we had to wait almost 40 years before we could return to it on March 18, 2011, the NASA's messenger spacecraft became the first to enter Mercury's orbit and over the next four years managed not only to photograph 100% of the planet's surface but also to collect extensive data on its geology, but before If any of this happened, Messenger had to take perhaps the safest route in the world.

The story of our exploration of the solar system by simply passing by Mercury to take some photographs like Marin did is difficult enough, but entering its orbit was thought to be either too difficult to achieve or too expensive to execute as a Cosmo chemist on the Mission. Messenger Larry Knitler explained that there are two main challenges to putting a spacecraft into orbit around Mercury: gravity and money. When you go from Earth to Mercury, you're falling into the sun's gravitational well, causing you to accelerate faster and faster as you get closer. and if you were to go directly from Earth to Mercury, this means you would basically speed past the planet or need to bring an incredible amount of fuel to slow down more than you could really afford, a number of missions never got further than pencil and pencil. paper.

While others failed at the proposal stage, it was only when Chen Juan Yen, a NASA engineer at the JPL Jet Propulsion Laboratory, provided a trajectory that could not only put a spacecraft into orbit but could do so at a very fast speed. low. It is estimated that the Messenger mission could actually begin taking flight at a bargain cost of $280 million, lifting off from Cape Canaveral on August 3, 2004. Kilm's trajectory before entering orbit around the smallest of all planets to Getting to Mercury with the right speed and on the right course would require a complex route that would involve a series of gravitational assist maneuvers around Earth, Venus and Mercury itself to reduce the spacecraft's speed relative to Mercury, combined with the instructions of its large rocket engine to finally insert it into orbit, this profile of the Mission allowed the Messenger to complete its journey without the need to carry the vast reserves of fuel necessary to slow its passage. firing rockets, this design made the ship lighter and cheaper, but ultimately much slower.

Almost 7 years was a long time to wait for the team to patiently chart their progress across the stars. Larry Knitler described the course of the Wizard's Pass as sneaking up on Mercury by taking a 7-year journey flying around the Sun many times, making multiple flybys around Mercury and Venus and each time transferring some of the ship's speed and energy to the Sun. planet so that it could slow down, so that when we finally reached Mercury after 7 years we could start our engine just a little to slow down even more and be captured by the planet's weak gravitational field when the messenger finally entered the orbit of Mercury at 0045 UTC on March 18, 2011, the trajectory on which it was established was highly elliptical in this orbit. took it on a 12 hour per hour cycle from 200 km above the planet's surface to 10,000 km away from it.

It may seem like an odd orbit for a spacecraft with the singular goal of getting as close as possible to Mercury, but it was an essential part of the mission's design. Des is vital to protecting Messenger from the ferocious heat radiated by Mercury's scorching surface. The sunlight reflected from the surface is so powerful that it would have literally melted the solder holding the spacecraft together if it had not been given time to cool. Between its closest approaches to the planet protected by a huge ceramic sun shield and its eccentric orbit messenger was able to begin its work for 2 years the spacecraft mapped virtually every part of Mercury's surface and the images sent to Earth revealed the planet that has been in the line of fire for billions of years, is too small to retain an atmosphere that could protect it from meteorites and lacks processes to recycle ancient terrain.

The ancient surface of Mercury is the most protected place in the solar system that the Mariner 10 Mission had allowed scientists. to see about half the planet, so the first real glimpses of Mercury's terrain came from Messenger flybys, as planetary scientist Nancy Shabbo explains. Before Messenger, we had only seen 45% of the planet and we saw some things during the flybys before us. went into orbit, but after orbiting the planet we have mapped 100% of the planet and we have seen almost everywhere some permanently shadowed regions that are still mysterious, but after mapping the planetcomplete we have a good idea of ​​what the surface looks like and Craters are absolutely a dominant landform.

This planet has been there for billions of years and it's been hit over and over again and it hasn't had many processes to destroy those craters among the thousands and thousands of craters on Mercury, the largest by far. Caloris plena is a 1,525 km diameter lowland basin that is believed to have formed in the early years of the solar system about 3.9 billion years ago. It was first detected when Mariner 10 sped by in 1974, but due to the trajectory and timing of The Craft. Only half of it was illuminated, so the full character of this crater remained a mystery for another 30 years until Messenger was able to photograph it in all its glory by taking one of the first photographs of it.

Messenger revealed that the calories were larger than he had previously estimated. a chain of mountains rising 2 km from the surface of Mercury, whose peaks create a 1,000 km boundary around the lava plains on the other side of the mountains, the vast amount of material that was lifted from the planet's surface At the time of impact it formed a series of concentric rings around the basin extending more than 1,000 km from its edge. The collision that created Caloris hit Mercury with such force that it also had more global consequences. Messenger photographed in great detail an area named in a not particularly scientific vernacular the strange terrain a region at the diametrically opposite point of the planet the antipode of caloris this area of ​​strange geological formations distinct from the rest of the surrounding terrain was probably created by the seismic wave of the caloris impact that reverberated throughout the planet until the end of its mission In 2015, Messenger continued to uncover many of Mercury's secrets, including some very particular surprises, using a combination of photographic spectroscopy and laser topography.

Messenger revealed tantalizing evidence that even so close to the Sun water ice can exist on the surface of a planet. Even though the Sun exploits much of Mercury's surface, the inclination of its axis of rotation is almost zero, so that there are craters and features around the planet's poles that never see direct sunlight, combined with the lack of atmosphere, these regions are always exposed to the frigid temperatures of space and it is in this environment that Messenger was able to record the clear signature of water ice here in the Eternal Night of a polar crater. It is cold enough for ice to survive for millions of years just a few meters from the savage ferocity of the Sun's light.

However, Messenger's most surprising discovery was Still to come, the mission's objectives had developed to explore the deep history of Mercury and provide data to test our theories about the planet's formation and early life. The messenger was equipped with a collection of spectrometers designed to analyze the composition of mercury in different depths, the messenger team had worked on a detailed set of predictions describing the planet's chemistry, but when the spacecraft began sniffing out the Mercury's surface soon became clear that our assumptions had not been entirely correct, as gamma-ray and , potassium and sulfur at much higher levels than they had expected up to that point, the working hypothesis had been that during the formation of Mercury and all the rocky planets as The Rock condensed and combined to form the planet, Heavier elements like iron would sink towards the center forming most of the core, while lighter elements like phosphorus and sulfur would remain near the surface, these more volatile elements would then be expected to be stripped away. from the surface, particularly on a planet like Mercury, which is so close to the Sun, and yet the messenger data confirmed that high levels of potassium and sulfur were detected, 10 times the abundance of the element on Earth or the Moon.

Volatile elements vaporize easily and when they are so close to the Sun they simply should not have survived the birth of the planet. Furthermore, the messenger's data confirmed what we had long suspected about the structure of Mercury: it is the densest of all planets with a massive mass. The iron core makes up 75% of the planet's radius, compared to just over 50% here on Earth. The core creates a strange twisted magnetic field that indicates the planet's internal dynamics are unlike anything we've seen before. All of this adds up to making Mercury something of a mystery, nothing at all.

Agreements The eccentric orbit, the abundance of volatile elements on the surface and the large iron core, everything points to the planet having a much more complex history than initially imagined and the only explanation to make sense of the messenger. The data is that Mercury was not born in its current sunburned position. It has long been known that the orbits of the planets are eternal, stable loops that sustain the structure of the solar system in an endless rhythm, but everything we are learning now suggests that this is far from the whole story. . Mercury, like its four rocky siblings, formed from molten rock a few million years later, when the young planet began to cool, its crust solidified, and its journey around the Sun transformed from being part of a swirling cloud. to a clearly defined passage an orbit the path that the young Mercury took, however, was most likely very far from the course that the young Mercury is now on.

It was born not as the closest planet to the Sun but at a much greater distance, far beyond the Venus orbits beyond Earth, perhaps even beyond Mars. This was a planet that arose in the mildest region of the solar system. It was far enough from the Sun to allow volatile elements such as sulfur, potassium and phosphorus to fold into its early rocks without being vaporized. the heat of the Sun, but perhaps close enough to heat its surface, perhaps even just enough for liquid water to settle on its surface. of life Mercury may well have existed, it seems that it really had its own moment in the Sun, but these hopeful beginnings were not to last today.

It is difficult to imagine the planets in any orbit other than our night sky. They feel eternal and permanent, so it's natural. Think of the solar system as a piece of celestial clockwork, a mechanism that works with perpetual and unchanging precision that marks the passage of time in time frames that we can understand days, weeks, months and years, the movement and trajectory of them. planets is simply a clockwork mechanism, we use these markers to plot the 24 hours of a day, the 365 days of a year and the lunar cycle, of course, is intimately linked to our months, beyond what the laws of gravitation Newton's universal principles first described in 1687 allow us to this day to trace the trajectories of all celestial bodies in the distant future and in the distant past.

This predictability of motion is what allows us to trace major astronomical events such as eclipses and transits in the distant future which is why, for example, we can predict that on September 14, 2099 the Sun, Moon and Earth will be precisely aligned to create the final total solar eclipse of the 21st century across all of North America, but 100 years ahead or behind is but a proverbial blink of an eye in terms of During the life of the solar system and for longer durations, the clockwork becomes much less reliable if there were only one planet orbiting a star, for example, if Mercury were the orphaned child of the solar system, we could precisely calculate the gravitational force between Mercury and the Sun and plot Mercury's orbit around the sun with essentially infinite precision, but we added one more planet to our rather empty imaginary solar system, let's say we turned it into Jupiter, so now there is a gravitational force between the three objects, the Sun, Mercury and Jupiter, and it is no longer possible to calculate exactly where they will all be in the future or where they were at some point in the past when there are more than two objects in play at the same time, we have what physicists call a chaotic system.

This means that planets can push and pull on each other moving entire orbits in ways we simply can't predict, so the further back in time we go, the less sure we are of the position of any of the planets. Our math fails, so we have to rely on circumstances. The evidence to reconstruct a picture of the past in the case of mercury is the Messenger evidence detailing the levels of volatile elements such as potassium and sulfur that allow us to begin to understand the early life of the planet and infer that mercury must have begun life. further into the solar system than it is today so what happened next?

How did a planet that began life at the solar system's sweet spot end up scorched inside? The answer lies in the other clue of the messenger confirmed for us: the massive Mercury. Iron core in relation to its size: Mercury has the most massive core of all the rocky planets. 75% of its diameter and almost half its mass is cast iron compared to about only a fifth of Earth's mass we suspected. of Mercury's composition for more than 150 years and that is due to a brilliant deduction by a German astronomer named Yan France Enker, who determined Mercury's mass by measuring the gravitational effect it had on a passing comet, a comet we now call , as expected, Anchor Comet with an approximation of the mass of the planet we can calculate the density of the planet and with that calculation approximate its composition, so we have known for some time that mercury is strange, but only with the arrival of the messenger we begin to reveal just how strange the smaller planet really is that, by precisely measuring Mercury's magnetic field, we have been able to confirm that, far from being a geologically dead planet, Mercury has a dynamic magnetic field driven by an internal force that indicates that the core is at least partially liquid, this goes against conventional thinking of planetary dynamics, because we would expect a planet as small as Mercury to have lost its internal heat a long time ago, just as Mars lost its heat due to its size, we would have expected Mercury's core to have cooled and solidified, but the Messenger data proved otherwise, by combining precise measurements of Mercury's gravity field with the extraordinary mapping of its surface messenger, it was discovered that the Mercury's structure is unique in the solar system: it appears to have a solid silicate crust and a mantle over a solid sulfide ion shell surrounding a deeper liquid core. layer possibly with a solid inner core at the center of the planet this defies all theories about its formation 4 and 2 billion years ago we know that the inner solar system was in turmoil in the midst of all this the newborn Mercury was found orbiting Far Away From its current intimacy with the Sun, surrounded by rocky debris and dozens of planetary embryos vying for position, the young solar system was still a place where planets could live or die, but it wasn't just the rocky planets that were disturbed. by Jupiter.

The largest and oldest of all the planets was on the move, and when a planet that size changes position there are almost always casualties, but for now all we need to know is that the evidence suggests that the juvenile Mercury was pushed around by the gravitational force. . of Jupiter on an inward trajectory finding itself flung toward the Sun and in the path of danger in the crowded orbits of the early solar system, such a change of course was fraught with danger and all the evidence indicated that this was the most violent and Definition of turns In the story of Mercury Being when the planet veered inward, collided with another embryonic world and shattered today we see the evidence of this fierce collision in the strange structure of this small planet, a giant core has been left behind the exposed interior of a planet. which was stripped of much of its outer shell, its crustal mantle, and lost to space after the collision, this collision not only transformed the physical characteristics of the planet but also pushed Mercury inward on a trajectory imbalance that we see reflected in the image.

The most elliptical orbit of all the planets, although we cannot be sure of these events, it is a brilliant piece of scientific deduction to use the evidence we have to create a plausible scenario of events that occurred unimaginably long ago and that fueled the first Rock of the Sun from a positionfull of potential for a place too close to the Sun to host any form of life a missed opportunity after four years of observing and its brilliant discovery of Mercury's ancient past messenger finally ran out of fuel on April 30, 2015 and added another crater But in this tortured world that once held so much promise, shrouded in an unbroken blanket of clouds, the next Sun Rock tells a very different story more than 50 million kilometers away.

Beyond Mercury lies a world that at first glance has the potential to be much more. More Earth-like than its scorching inner companion, Venus is perhaps the most mysterious of all the planets found on the inner edge of the so-called habitable zone. This is a planet that has kept its secrets for centuries. It has been bothering us with its brightness on Earth for a long time. In the morning and afternoon the sky is very bright because it is a large planet about the same size as Earth, it is not very far from either of them and the clouds that surround it are highly reflective and reflect 3/4 of the light that reaches them, that is frustrating.

But the most tantalizing thing about Venus is that even when you look at it through a large telescope it is featureless, you never see the surface, meaning that until the 1950s scientists could only speculate about what lay beneath; In the late 19th and early 20th centuries many thought that beneath its clouds Venus hid a mirror world of Earth, if not the home of complex sentient life, certainly harboring basic life forms confronted with that impenetrable mantle. Our collective imagination fueled the idea of ​​a living, breathing world beneath the clouds, a shroud it meant for the first half.

In the 20th century we lived convinced that we were not alone in the solar system. Nobel Prize-winning chemists Van Arenus was one of the most renowned scientists who fueled the mythology of what was hidden behind the cover of Venus, as many of the scientists of his time Arenus left to his His curiosity spanned many different areas. , including astronomy, and extensively hypothesized about the Venusian environment, assuming that Venus's clouds were composed of water. He wrote in his book The Fates of the Stars that a large part of the surface of Venus is undoubtedly covered. with swamps creating an environment similar to the rainforests found here on Earth.

Expanding this image, he suggested that the planet's complete cloud cover created a completely different uniformity to the climate extremes that define different parts of the Earth in the imagination. of Aran: this stable environment. with a consistently uniform climate across the planet meant that any life on Venus lived without the evolutionary pressures of the changing environments that drive natural selection here on Earth, leaving Venus in an evolutionary limbo similar to the Carboniferous period that describes a world full of prehistoric swamps and The Dark Forests' use of Aran created the perfect canvas for science fiction writers of the time to conjure up a series of curious life forms lurking beneath the clouds.

Today, Arenus is much less known for his fertile imaginings of the wildlife of Venus than for his work on Earth's climate. In 1896 he was the first scientist to use basic principles of chemistry to demonstrate the impact that the atmosphere can have, in particular carbon dioxide levels, on the surface temperature, a process that was called the Aran use effect but is now known as The greenhouse effect, an effect that would not only have profound consequences for our understanding of our impact on our own planet, but it would also be vital in explaining the true nature of Venus beneath the clouds.

In the 1920s, as Earth technology improved, we stopped painting the surface of Venus. Venus with our imagination and we begin to fill in the gaps with facts. The first spectroscopic analysis of the planet's atmosphere suggested that it was neither water nor oxygen that filled the clouds of Venus, so some thought this hinted at an arid, desert land below, others speculated that it formally filled the air, leading to the belief that Venus was not only a dead planet but also a pickled one, but in the 1950s the true nature of Venus began to be revealed as more precise ground-based observations suggested the presence of overwhelming levels of a defining gas.

In the atmosphere of Venus, this was not a planet wrapped in clouds of water and oxygen, nor preserved its shape, this was a planet wrapped in a layer of carbon dioxide and, as a reuse had shown on Earth, this almost It certainly meant whatever was beneath the clouds. The heat would be beyond the limits of even the most hardy life forms on Earth. As the first spacecraft to explore our sister world was being built, it became increasingly clear that visiting Venus would be far from easy and far from welcoming. In the early 1960s, the Soviet Union began a series of missions under the name of the Venera program that attempted to explore the atmosphere and surface of Venus directly for the first time.

The initial launches of the veneer program failed before they had even left Earth's orbit, but within a couple. After several years, the program began to have some success. Vineer 1 was successfully launched on February 12, 1961, designed as a flyby mission. It is believed to have passed within 100,000 kilometers of Venus, but a complete failure in the spacecraft's lemetry meant no data was obtained. Returned to Earth, as far as we know, Venera 1 is still orbiting the Sun to this day. Venera 3 attempted to go a step further and was designed to enter the atmosphere of Venus to take the first direct measurements, however, upon crossing the atmospheric boundary, the probe's systems failed and no data was obtained as it plummeted towards the floor.

All that was left for Venera 3 was the historical position of being the first human-made object to crash into the surface of another planet despite multiple failures to which the Soviets did not give up and in October 1967 Venera 4 entered the atmosphere of Venus and returned data supporting ground-based observations that revealed for the first time that the cloud cover surrounding Venus was composed primarily of carbon dioxide, 90% to 95%, 3% nitrogen and only trace amounts of oxygen and water vapor Vineer 4 confirmed beyond any doubt that this was not a second Earth, as it descended through the thick clouds, the temperature rose to 262 °C, the pressure atmospheric pressure increased to 22 standard atmospheres, 2200 kPa, and was still 26 km above the surface.

Vineer 4 parachuted to the surface and returned data to Earth where, while it confirmed its own imminent death, it was a spacecraft that was not designed to survive the intense pressures and temperatures it was measuring, much less at the lack of the water landing for which it was designed. Because the spacecraft failed during Descent and was lost long before it reached the surface gradually through subsequent missions Soviet scientists began to overcome each and every challenge that Venus put in front of them. Vineer 7 was built to survive the most violent of landings and even though its parachute failed, it reached the surface intact in 1970 and was able to use its damaged antenna to transmit limited temperature data for 23 minutes before expiring.

Vinera 9 not only reached the surface and operated for 53 minutes in October 1975, but it was also the first spacecraft to successfully deploy its camera on the ground and transmit an image to Earth. In the first photograph taken from the surface of another planet, the fractured black and white image revealed a desolate rocky landscape with measurements confirming it to be a scorching 485 degrees C with an atmospheric pressure of 90 ATM. It collapsed when Venera 13 collapsed. launched on October 30, 1981, mission ambition and confidence in delivering data from the surface had been radically transformed. Vineer 13 operated for 127 minutes at temperatures of 47°C and a pressure of 89 Earth atmospheres.

The probe's deployed cameras took the first color image of the surface of Venus. Spring-loaded arms measured the compressibility of the soil while a Mechanical drilling took a sample from the surface of Venus which was analyzed by an onboard spectrometer if that were not enough microphones were deployed on board to record the strong winds that were supposed to be whipping the surface of Venus. The first recording of sound from another planet when Vineer broadcasts came to an end in 1983, there was not the slightest doubt about the hostility of Venus. far from the benign Aquatic World we had once imagined, the reality was that this was not a sister we recognized in our search for a place like our home in the heavy, we had found a hell of toxic fire Venus is an enigmatic world, almost resembling to the Earth in its position and potential and yet as far from Paradise as it is possible to imagine, if the history of Mercury is one of catastrophic orbital changes and that of the Earth of balance and stability, the history of Venus is a tragedy , a story of subtle but relentless decline, so why did it all go wrong for Venus, why did a world born with so many similarities to Earth take such a different path to answer that we must look beyond the tortured planet we see today and return to a time when Venus was a young and prosperous planet 4 billion years ago? a familiar world, a world created from the same dust as the Earth, which was born about the same size and settled in an orbit that seemed far enough away from the sun's glare to allow a precious process to begin to take hold in almost everyone. imaginable places.

The way Venus' early life mirrored that of our own world As its newly formed crust settled and cooled by the violent heat of its birth, an atmosphere began to grow around the young Planet fueled by gases bubbling up from molten rock beneath its surface, as well as captured from the clouds of gas and dust it passed through in its orbit around the sun attached to young Venus, this thin layer of gas would certainly have contained nitrogen, oxygen and carbon dioxide, but most intriguing of all is that it would also have contained large amounts of water vapor high in the Venusian atmosphere, this water vapor eventually cooled enough to change state from vapor to liquid and with that transformation began a process which perhaps for the first time on any of the planets would have seen conditions become perfect for drops. of liquid water to take shape and begin to fall from the sky of Venus these were the first rains of the solar system falling on the dry plains of Venus gradually these rains would not only have fallen but would have flooded the surface The rivers would have flowed and the ocean little deep would have taken a large SES of the surface of the planet Venus, perhaps even before Earth became a water world, a planet with cloud-filled skies and a surface filled with oceans that feed the water cycle around this young planet.

How can we be sure about this blue version of Venus? existed unlike Mars, where we can see evidence of its watery past etched into its surface. We have no direct evidence of the presence of liquid with water on the surface of Venus. The only physical evidence we have suggesting the planet's watery past comes from measurements. Taken by NASA's Pioneer Venus spacecraft in 1978, one of its most surprising discoveries revealed an unexpected amount of heavy water in the atmosphere compared to hydrogen. This DH ratio is much lower on Venus than on Earth and that's interesting because when the two planets formed, the ratio would have almost certainly been the same because hydrogen is much more easily lost from an atmosphere than dyum.

This smaller ratio suggests that Venus has lost much more water than Earth over its lifetime, the signature of a long-lost primordial ocean. Cosmochemistry Knitler explains that scientists believe Venus once had a lot of water in its oceans, but lost it over time and perhaps in oceans as recently as a billion years ago. The reason we can say this is because of the isotopic composition of hydrogen measured in its atmosphere. By spacecraft now hydrogen has two types of isotopes, while most hydrogen atoms are just one proton in the nucleus. Some small fractions are what we call dyum which have one proton and one neutron, so they weigh twice as much as normal hydrogen.

What happens when water evaporates from a planet or the atmosphere is that water molecules containing hydrogen are much lighter than water molecules containing deuterium, so they evaporate more easily and more can be lost.easily, over time, as water-containing molecules evaporate. if it lags behind normals, a ratio of dyum to hydrogen builds up, and by calculating from the ratio measured today, we can calculate how much water has been lost over billions of years of evolution and on Venus It's pretty much nothing. This is solid evidence, but it begins to point us in one direction and without any further exploration of the surface we have had to rely on an accumulation of indirect evidence to begin to paint a more detailed picture of Venus's watery past as we almost always do.

For all of our understanding of the planets, the evidence that built this picture has been accumulated over decades of exploration, from the first varnish emissions landing on the planet to the pioneering Venus orbiter and the more recent Melan mission, which Not only did it transmit extraordinary radar surveys of the surface of Venus, but it provided the first complete topographic map of the planet collected over a 4-year period in orbit, combining all the data accumulated over decades of exploration, it has allowed us to delve into the past of the planet using the same tools. that allow us to model the future of climate change here on Earth to create climate models of Venus in the past, present and future.

The results of this most recent analysis by a team at NASA's Godard Institute for Space Studies all point to the same conclusion. In the distant past, Venus was a planet covered in shallow primordial oceans. Some estimates suggest that this water world was far from a fleeting blue planet like our own, which could have existed for about 2 billion years and perhaps only disappeared about 700 million years ago. It's a tantalizing idea that a world so similar to our own has existed for so long with liquid water on its surface that we know life quickly took over our Blue Planet, 500 million years after Earth formed, so There seems to be good reason to be suspicious. that if Venus really was as wet as models predict, it might have come to life, too.

Exactly what happened in the lost rivers and oceans of Venus, hidden behind the clouds, has yet to be discovered, we have not yet returned to look for anything. Signs that life once took hold here Our exploratory attention has focused on Mars as a planet that not only has a fertile past but is also a possible target for human colonization in the future. We know for certain that no life, at least no life that we understand, could exist today on Venus and perhaps even evidence of some biology on that long-lost water world has long since faded under the oppressive heat, volcanism. unrestrained and extreme pressures of the planet today Venus has the slowest rotation of any planet in the solar system taking 243 Earth days to complete one rotation on its axis this period is known as a siderial day which is different from a solar day the time that It takes the sun to return to the same point in the sky on Earth.

The sidereal day at 23 hours 56 minutes and 4.1 seconds is very close to the solar day, which lasts almost exactly 24 hours, but on Venus the difference between these two periods is much longer even though the planet takes 243 days to rotate on its axis when combined with its orbit a solar day on Venus lasts 116 16.75 Earth days, meaning that each day on Venus lasts almost 4 months on Earth And not only that, but Venus also rotates from east to west, one of only two planets to do so along with Uranus, so on this toxic world a sunrise literally lasts for days as it slowly moves across the sky.

This slow progression of the Sun in the sky of Venus due to the progressive rotation of the planet has raised many questions about how in the past the planet would have warmed and how the climate would have been affected by such a different rotation compared to that of the Earth today the climate of Venus is what is known as isothermal there is a constant temperature between the sides of day and night and between the equator and the poles this is because the thick atmosphere literally acts as a blanket that dissipates heat from the Sun, so the only real temperature variation on the surface of Venus occurs due to altitude differences in its past;

However, this may have been very different with a more Earth-like atmosphere, so the sun would have been hitting the planet's surface for days on end. To complicate things further, we know that a planet's spin is intimately linked. related to its climate and we have strong evidence to suggest that the speed at which a planet rotates is directly related to its chances of habitability, until very recently it was assumed that the slow rotation of Venus must have been caused by the presence of a thick atmosphere early in its history that in effect acted as an interruption in the planet's spin;

However, recent studies now suggest that the planet could have had such a thin atmosphere. of the modern Earth and we are still done with its slow rotation gradually as we begin to build a picture of ancient Venus, we begin to see beyond today's cloud cover to an ancient planet with an Earth-like atmosphere and a day that lasts more than 200 Earth days. As the sun hit the ocean-covered surface to make sense of the climate of this Earth-like Venus, the Godart Institute team needed to make another adjustment or postulation to be more accurate in the model with the Sun hitting one side of the surface.

For much longer than on Earth, the rate of evaporation from the oceans would be much higher and potentially incompatible with the water world we suspect exists, but by simply adjusting the amount of dry land on the surface of Venus, especially in the tropics, the effect is dramatic. with a higher percentage of land, the models suggest that even slow rotation would not dry out the planet and could have retained enough water to be mature to support the emergence of life by combining all this data that the G team has painted. our most up-to-date image of early Venus and it is a captivating image within the nascent solar system.

It is an Earth-sized planet with an atmosphere similar to what we see on Venus today. The days lasted for months as the sun slowly crossed the sky. from west to east rising and setting over a vast shallow ocean, eventually data from radar measurements taken by NASA's Melan mission in the 1990s were used to paint the last strokes of this long-lost world filling the L lands with water, the topography of this The ancient world emerges with the highlands exposed like the Venusian continents. Everything points to the possibility that Venus could have been the first habitable world in our solar system.

So what changed? To find out, we must look not only at the planet in isolation, but also at the star around which it orbits. No planet lives its life in isolation. Venus, like all planets, is not just part of a configuration of planets and moons, asteroids and comets, but is also part of a solar system. A driven system more than anything else. Today, because of the star at its center, the sun shines brightly in our skies, bathing our planet in enough starlight to keep the oceans from freezing, but not too much to evaporate them. The Earth is in the sweet spot that we call the Goldilocks zone, but as we have already seen in this chapter, nothing in the solar system lasts forever and what we see today is not what we will see tomorrow or what we would have seen yesterday as our sun ages, it is gradually burning hotter and hotter, this is because as the process of nuclear fusion ages, the fusion of hydrogen mainly into helium gradually leads to an increase in the amount of helium in its core.

This increase in helium causes the sun's core to contract, which in turn allows the entire star to shrink in on itself creating a pressure increase that results in an increase in the fusion rate and therefore production. of energy from the sun increases if tomorrow the sun burns hotter than today, of course it makes sense that in the early days of the solar system our sun shone much less, it is a life cycle that is common to all main sequence stars, the category of star that includes our sun and, as the most common type of star in the universe, we have been able to study this life cycle in great detail, allowing us to make immensely detailed predictions about our child's characteristics in the past and in the future. future turning back the clock the current consensus among astronomers is that 4 billion years ago the faint young sun was at least 30% dimmer than today, this colder sun would certainly have had a major impact on all terrestrial planets , the Earth would have been much colder and, since it received much less solar energy, it remains a mystery why our planet was not frozen.

Instead, at that time on Earth the first life was just beginning. liquid water that we are pretty sure covered its surface at the same time 3.5 to 4 billion years ago the young Sun would have bathed Venus in a warmer glow this ocean world found itself in its own sweet spot a world kept in a delicate balance With the Sun weakened and restricted, the Earth's atmosphere of Venus could act as a soft blanket keeping the surface warm and covered by a large amount of liquid water, but even with this additional solar energy we believe that Venus would have been much colder than the earth.

In fact, today we believe that the temperatures at that time would have been like a nice spring day here on Earth. It wasn't going to last slowly. The young Sun grew brighter and its increased energy output caused temperatures to gradually rise, which in turn began to rise higher and higher. water vapor in the air thickening the atmosphere and sealing the fate of the planet, although the mass of Venus may have persisted for billions of years as the surface warmed and the atmosphere thickened, the fate of this planet was already established driven by an unstoppable process that we have recently become.

Very familiar here on Earth with the greenhouse effect, it is a process that has the power to both protect and destroy a planet, but despite this power, it actually boils down to fairly simple physics: it is about how solar radiation interacts. with the constituent parts of an atmosphere in the case of the Earth as Solar radiation reaches our atmosphere. Part of it is reflected directly into space. Some is absorbed by the atmosphere and clouds, but most of the sunlight, about 48%, passes directly through the atmosphere and is absorbed by the Earth's surface, where it is heated. So much solar radiation reaches the surface is because gases in our atmosphere, such as water vapor and carbon dioxide, are transparent to light in the visible spectrum.

When you think about it, that's pretty obvious because there is a visible light source in the sky, the Sun, and we can all see it, but it's a different story when the sunlight heats the Earth's surface and radiates it not as visible light. but as thermal radiation of longer wave infrared light, we cannot see this light except as it radiates. From the surface of the Earth, carbon dioxide and water vapor absorb infrared, trapping that energy and that is why the planet maintains a higher temperature that is closely linked to the constituent parts of the atmosphere the higher its level of gases such as water vapor, carbon dioxide, methane and ozone.

The greater the greenhouse effect and the greater the rise in temperature, despite the very real threat this now poses to the future of our planet, the greenhouse effect alone is not necessarily a bad thing: the Earth would have an average temperature of around -8°C without it, but as we are currently witnessing here on Earth, the balance of those gases changes and things can change very quickly at some point in Venus' past, water vapor levels elevated to The atmosphere due to the heating of the Sun caused the greenhouse effect to become precariously more intense with less and less energy from the Sun escaping.

Environmental temperatures began to increase exponentially until the day came when the last drops of rain fell on the surface of the Earth. planet the heat evaporating rain long before it could reach the ground Venus had reached a Tipping Point with rising temperatures feeding more and more water vapor into the atmosphere, an uncontrolled greenhouse effect occurred that moved the oceans away, causing which led to the planet's surface becoming so hot that carbon trapped in rocks was released into the atmosphere, mixing with oxygen to form increasing amounts of another greenhouse gas, carbon dioxide, with no water left in the surface and without other means to remove it.

The carbon dioxide accumulated in the atmosphere would put the planet on a course thatwould result in the scorching body we see today and therefore that of Venus. moment when the sun came to an end earthlings take note when it comes to the greenhouse effect there is a precariously thin line between keeping a planet warm and frying it Of the four rocky worlds only one has managed to navigate through the instability and constant change of our solar system for the last 4 billion years and maintain the characteristics necessary to support life Mercury lost its fight early when it was thrown towards the sun Venus flourished at first before slowly boiling and Mars, the garbage dwarf, froze.

It was long ago a wasteland, the only planet among Earth that has persisted with adequate stability over the past 4 billion years to allow liquid water to remain on its surface and an atmosphere thick enough to maintain its climate. calm, no events that are too hot or too cold have occurred. We have been shaken and extreme temperatures have risen and fallen, but never outside the parameters necessary to support life in a chaotic solar system full of planetary energy. The Earth is a shining example of stability and evidence of this can be found around every corner. and the corners of the planet today The Earth is dominated by life, the land and the seas are filled with Millions and millions of species with thousands of new life forms discovered every year somehow, even when disaster threatened, the Earth has remained a living world as countless species have come and gone.

Life that has always disappeared has always persisted, it is woven into the fabric of the planet, it is an integral part of every continent and every ocean life plays a crucial role in maintaining the balance of life. atmosphere that keeps our planet warm, but we know for sure that it cannot last until the Kamchatka Peninsula. Eastern Siberia is one of the most inhospitable places on Earth, a volcanic wasteland dotted with thousands of hot springs. It is here where we find some of the most resistant living beings: Extremophiles survive here and are able to withstand temperatures and pH levels higher than any other terrestrial life. ways we've discovered Kamchatka is part of the Pacific Ring of Fire, and despite its remoteness, biologists have long been drawn here to explore its toxic bubbling cauldrons for signs of life.

Complex life, animals and plants struggle to survive in temperatures of around 50° C, so the search For Life here is about looking for single-celled life forms, WS bacteria and ancient ARA microorganisms that are somehow able to resist in this hostile environment. Life forms such as acidilobus aticus, an ARA that can be found in a hot spring where the water is so acidic that it reaches a pH of two and where temperatures rise to 92° C. In other parts of the hydrothermal field, bacteria such as desulfurella acetivorans that live happily in pools that are close to 60° C, but these are the real Hot Heads in one of the In the largest and hottest pools investigated by scientists, a large number of microbes have been found that live at temperatures close to 97 °, making it one of the hottest, if not the hottest, environments ever studied for signs of life on Earth, but to find the hottest heads on planet Earth, you don't need to look at the earth, but to the depths.

Under the sea, in the farthest depths of the Atlantic, around the black smoke hydrothermal vents that emerge from the ocean floor, we find strains of ARA that can survive temperatures of 122° C and perhaps even higher than these forms of rare life Forms live at the very limits of biology. Unique adaptations to its cellular chemistry allow the proteins and nucleic acids that create the structure of the microorganism to function while the membranes that protect the cells use different fatty acids and lipids to keep the cells stable in the environment. Higher temperatures may lead to even more resilient life forms that we are yet to discover, but the thermophilic microorganisms we have identified and investigated so far in places like Kamchatka point to the fact that life has its limits.

Evolution by natural selection can only adapt to a certain point. and although it is impossible to imagine what life on Earth will be like in about 100 million or even a few billion years, we know that biology is limited by thermodynamics and therefore we can say with some certainty that there will come a time in which the Earth is too hot for living beings to exist. Natural selection will eventually run out of options as the laws of physics overtake it and all life will come to an end. When this will happen, no one can be sure, but as the sun ages and warms.

Temperatures on Earth will rise rapidly today, the planet's average surface temperature is 14.9°C, but with just a 10% increase in the Sun's luminosity, the average temperature will rise to 47°C and the increase of temperatures will cause major storms across the planet. rains will remove carbon dioxide from the atmosphere and it will be locked in as sedimentary rocks form, trees and plants will struggle as they are robbed of the gas that sustains them until photosynthesis finally ceases, our planet's lungs will fail and The precious oxygen produced by green plants and algae will decrease when the main food source disappears, the food chain will collapse and the era of complex life on Earth will come to an end.

Heat-loving Extremophiles may flourish for millions more years, but eventually Nuclear Physics will come to an end. work and as average temperatures rise above 100°C the last pockets of life will be extinct from the earth, we can say with confidence that this will happen because we can map the future of our sun with much more precision than the future of the earth. Understanding nuclear physics allows us to predict what happens inside the cores of stars and therefore we can see the past, present and future of stars like ours written in the night sky. The skies are filled with bright examples of stars that give us insight into the future of our sun Arcturus, for example in the constellation Bootes, is one of the brightest stars in the northern hemisphere;

It is about the mass of the Sun, perhaps a little heavier, so in the distant past it would have had remarkably similar characteristics to our current star. although Arcturus is between 6 and 8 billion years old, potentially 3 billion years older than the Sun, and since it is no longer a main sequence star, it is now in the red giant phase, has run out of fuel, has It has swollen up to 25 times its original diameter and is about 170 times more luminous even though as its core slowly burns, it is cooling. To see even further into the future, we need to look toward the brightest star in the northern sky, Sirius, the Dog Star, as it is commonly known, twice the mass of the Sun and still completely on the main sequence but obscured. by the glow of Sirius a is a faint companion, a serious bee, this is a star that has already burned its fuel, has swelled into a red giant and the outer layers have drifted into space, leaving the core of a fading star, about the size of Earth, known as a white dwarf, these stars are just two examples among many that point us to the ultimate destiny of our Sun, a destiny that we believe will unfold over the next 5 billion of years approximately.

Like Arcturus, when the sun exhausts its hydrogen fuel, its outer rim will inflate and enter a red giant phase that will expand millions of kilometers into space, engulfing Mercury first. Venus's fate will be sealed next as the sun expands further, with some models predicting that Earth may escape the burning edge of its neighbors heated to 1,000°C but hanging beyond the edge of the dying star as it its orbit is extended due to the Sun's decreasing mass, dead but not destroyed. Earth and Mars will orbit as if burned. relics of what once were the era of the four rocky inner planets will end the billions of lives lived on the surface of one of them is but a distant memory, but within our solar system lies another family of rocky worlds whose time on the sun may be far beyond the asteroid belt, millions of kilometers away from the sun-kissed planets of the inner solar system.

The gas giants Jupiter and Saturn are home to another family of rocky worlds. Jupiter alone has 79 known moons orbiting it. shapes and sizes we have been observing these moons since Galileo Galile saw four of them IO Europa gained and Kalisto knew them as the Galilean moons more than 400 years ago with his telescope Transforming our understanding of our current place in the solar system, we have explored the The Galilean moons not only from afar but up close and we discovered that they are dynamic worlds. IO is fiercely volcanic and the ice moon Europa shows tantalizing evidence on its surface that points to a subterranean ocean located beneath its icy crust.

Ganid and Kalisto constitute the last two Galilean moons. moons and, like Europa, are rocky worlds with abundant water ice on their surfaces and perhaps their own oceans lurking beneath these three rocky, frozen worlds, all located in the cold reaches of our solar system touched by the distant Sun but barely warmed. dormant until perhaps someday the aging sun will reach out and turn these bodies into ocean worlds for the first time. The next planet to emerge Saturn also has its growing family of moons, among its collection of more than 60 confirmed satellites is Titan, the only known moon. with a dense atmosphere and liquid lakes on its surface, although they are mainly methane, not water, and Enceladus, an icy Moon like Europa, with a liquid ocean deep in its ice, until we step back and explore further, we cannot be sure of what's underneath. its surface, but the possibilities that the Cassini probe has so tantalizingly hinted at make it one of the most interesting places to visit within the next generation of interplanetary expeditions.

All these ice worlds lying dormant in the icy reaches of the solar system offer promise. of a very different future, one in which the rocky worlds of the inner solar system have been burned to ashes and a new generation of worlds waits to awaken. Ice worlds will become water worlds heated by the expanding Sun until our dying star finally collapses into a white dwarf Mars is a mirror to our dreams and nightmares to the naked eye the planet exhibits a blood-reddish hue in the imagination God of War Star of Judgment through a small telescope is the most earth-like of the planets with cinear deserts and white polar ice crowning a world we could imagine visiting, perhaps even settling in the 19th century.

Astronomers were convinced they saw prayers, mountain ranges, and canals carrying meltwater from high latitudes to arid equatorial cities. Some thought the Martians were a peaceful civilization far ahead of the threat from others. the Gulf of space minds that are to our minds what ours are to those of perishing beasts vast, cold and unfriendly intellects looked at this Earth with envious eyes wrote HG Wells in his classic science fiction novel The War of the World in 1897 Nature Mars remained a mystery well into the 20th century because the planet is small and distant and therefore difficult to observe with ground-based telescopes.

Even the Hubble Space Telescope, high above the distorting effects of Earth's atmosphere, produces images that at first glance would not have been prevented by Wells's imaginative publication of polar caps, high clouds and dark regions surrounding deserts. The first flyby of Mars by NASA's Marin Four spacecraft on July 15, 1965 abruptly ended the romantic notion of Mars as a twin. habitable or potential enemy of the Earth. These images revealed an arid surface reminiscent not of our Blue Planet but of our Moon desiccated during the night. We discovered with certainty that Earth is the only planet in the solar system capable of supporting complex life, and contemporary accounts of the Mariner impact during the flyby suggest that this was a powerful realization.

In November 1965, the Bulletin of the Atomic Scientists carried an article titled The Message from Marin Four and the message was Bleak. The shock of Marin's photographic and radiometric reports is due not only to his denial of the terrestrial image of Mars, but also to the Revelation that there is no secondopportunity, at least not in the solar system. President Lyen B. Johnson was reported to have remarked that life as we know it, with its humanity, may be more unique than many have thought. The hesitation in the first words reveals that Mars is here as a symbol of our cosmic isolation.

It is as if deep or perhaps not so deep in the subconscious the power of the 60s. The intermediaries, even the president, suddenly understood that the Earth is much more fragile and precious than a dispassionate analysis of their politics might suggest. risky during the Cold War or perhaps from perspective. The Apollo 8 Earthrise, the photograph that brought such a positive end to a turbulent 1968 by placing the Blue Earth against the gray Moon, was three years away, but Red Mars provided a preview of the answer. Carl Sean co-authored a paper that jokingly suggests that all was not lost.

Marin four took only 22 photographs with a resolution of more than a kilometer in a strip crossing the region in which the astronomer Peral LEL had drawn channels from his observatory in Flagstaff, Arizona, in the early 20th century. the heat of the Arizona desert LEL wrote that Mars was Chile, but no more so than southern England, which certainly supported a civilization of sorts using several thousand photographs of similar resolution taken by weather satellites in Earth orbit. Sean and his co-authors found only one feature that unequivocally indicated the presence of a civilization on Interstate 40 in Tennessee. They concluded that Marin four would not have detected human civilization if it had passed by Earth, we do not expect intelligent life on Mars, but if there was intelligent life on Mars. comparable to that on Earth, a considerably more sophisticated photographic system than Marin 4 would be needed to detect it the nonexistence of a Martian civilization was confirmed by The Marin 9 mission in November 1971, the first spacecraft to orbit another planet Marinina 9 achieved a With a photographic resolution of 100 m per pixel and no sign of past or present intelligent life was detected, the twin Viking landers in 1976 failed to detect even microbial life, although the combined results of the suite of microbiology experiments carried out by the spacecraft space are not considered unequivocal.

Because Martian soil may be enigmatic, as a phrase from NASA's official report coins, chemistry may have masked any biological activity in retrospect. The fact that Mars is not teeming with life today is not so surprising that Mars orbits 50 million miles farther from the Sun than Earth and receives less than half the solar energy. It is a small world with a tenuous atmosphere that provides little insulation or greenhouse effect. NASA's Curiosity rover in Gale Crater has measured temperatures above 20°C at midday, but in the early morning hours it is experienced -120 as Alfred Russell Wallace wrote in 1907.

Any attempt to transport water through the Martian surface today would be the work of Mad Men instead of intelligent beings. There are no canals, no cities or envious eyes. The planet is a frozen hyperAR desert. Too far from the Sun to support complex life, but this has not always been the case, observations from our fleet of orbiting spacecraft and landers have revealed a complex and varied past. Once upon a time, the red planet shone, blue streams ran down slopes and rivers. winding through valleys carved by a water cycle from the earth to the sky and back again from the mountains and highlands to the sea, this presents a huge challenge to planetary scientists, in short, no one would have been surprised if Mars It would always have been an inert rock because it is a small planet far from its star but the geological evidence is unequivocal the surface tells a different story Mars then remains an enigma as a wandering red star that sparked the imagination of the ancients as a telescopic image too small and shifting for visual or intellectual clarity it became our twin.

When the spaceship flew by, surprising us as we considered our cosmic isolation, the red planet was relegated in our Collective Consciousness to the status of just another rock that glowed in the night, Then we land and discover a world that was once habitable and could be Once again, a map of Mars can be read like a history book, unlike on Earth, where constant erosion, tectonic activity and volcanism have erased the deep geological past. Mars has been relatively dormant for most of its life, scarred by the collisions of the turbulent first billion years after formation. of the solar system can still be seen from orbit ancient cataclysms documented beneath a thin film of dust NASA's Mars Global Surveyor spacecraft spent 4 and a half years mapping Mars in the late 1990s and provided detailed maps with colors corresponding to differences in altitude, just like on Earth there is significant variation, but the geological features on our smaller sister world are much larger and bolder.

The highest elevations on Mars are located at this elevation of a large volcanic plateau and home to the largest volcano in the solar system, Olympus Mons, at more than twice the height. height of Everest Olympus Mons Towers 25 km above the Amazonus plain lowlands to the west and its base would fit within France almost cutting a deep scar southeast of Olympus Mons is Val Marineris, named after the Mariner 9 spacecraft that it discovered. a canyon that dwarfs anything on Earth the Grand Canyon would fit into one of its side channels the lowest points of Mars are located in the helas impact basin the largest clearly visible impact crater in the solar system from the highest points at the rim of the crater to the floor Hass is more than 9 kilometers deep it could contain Mount Everest the atmospheric pressure on the floor is twice that at The Rim high enough for liquid water to exist on the surface in a narrow range of temperatures these are extreme altitude differences for a small world 30 km from the summit of Mount Olympus to the ground of Helas on a much larger Earth, for comparison, there is only 20 kilometers difference between the summit of Everest and the Challenger.

Deep in the Mariana Trench lies the most striking and oldest elevation difference on Mars. is that between the northern and southern hemispheres of the planet known as the global otomy Mars is an asymmetric world, the northern hemisphere has on average 5.5 km less altitude than the southern, there is no consensus on how the dichotomy was formed, apart from It was early in the planet's history and before the large impacts that created the Utopia and Kryy basins about 4 billion years ago, at some point later the lands of northern L were resurfaced by volcanic activity in a similar manner to the soft lunar seas, which explains their lack. of craters relative to the much older terrain to the south The oldest terrain on Mars is located in the Nois Tera region of the Southern Highlands.

It is characterized by strong craters that are reminiscent of the far side of the Moon. Even small craters in the Noan highlands are heavily eroded, suggesting the regular, if not persistent, presence of liquid water; there are dry river valleys and deltas and evidence of water accumulating in the craters and overflowing their walls. forming interconnected networks of lakes. This is how we know that Mars was once a warmer, wetter world. At least occasionally, evidence is written across Noah's Land, in contrast, the younger Hesperia Plum terrain shows much less evidence of regular water erosion, but bears the scars of occasional catastrophic floods that cut deep valleys during very short time periods and may have large temporary lakes or seas formed.

The plenary Amazonis region shows few signs of water flow, fewer impact craters and less evidence of active volcanism, suggesting that it formed more recently when Mars was significantly less active. geologically the persistence of surface features for many billions of years in the Noan Hesperian and Amazon regions has led to the historical epochs of Mars being named after the distinctive terrains that still bear the characteristic marks of climate and activity geology that formed and sculpted them. The Noan period was the earliest and wettest and coincided with the origin of life on Earth about 4 billion years ago, when conditions on both worlds appeared to have been very similar, the Martian atmosphere may have been denser. than Earth's and dominated by carbon dioxide, but important questions remain about how such an atmosphere could have warmed Mars enough to produce the warm, humid climate and how the Maven spacecraft currently in orbit missed that atmosphere. around Mars aims to answer this question the Noan period Ended when Mars became increasingly cold and arid around 3.5 billion years ago just as life was taking hold on Earth the Hesperian period The time of catastrophic floods It extended from the end of the Noan until about 3 billion years ago, when Mars entered its current frozen arid phase, marked by occasional volcanic activity and the large-scale movement of ice, but with very little evidence of water flow during the long three billion.

The frozen year from the end of the Hesperion to the present day is known as the Amazon. This is a summary of what we know about SAS. Savants pose a significant challenge to planetary scientists given a warm, humid, and seemingly stable world at the beginning of its history. The loss of atmosphere and the descent to the current aridity. What happened to water on Mars? Was it lost in space? Does it persist today as surface ice or in rocks or underground deposits? If so, how much water is still accessible? Could we exploit the old ones? Mars reservoirs to sustain a human colony and perhaps most significant of all, life emerged on the planet during the Noan period coinciding with the origin of life on Earth and could that life still be present on Mars today?

The current fleet of spacecraft orbiting Mars and roaming its surface has been designed to answer these questions. Mars today is a planet full of activity. Communications with Earth and the Martian Internet are managed by the Mars Reconnaissance Orbiter M, an orbital bridge between worlds that carries the high-altitude instrument. camera with resolution high enough to see basketball-sized features on the Martian surface the Mars Color Imager Marque Camera monitors the Martian climate and the Compact Mars Chrism Imaging Reconnaissance Spectrometer identifies mineral deposits, particularly those formed in the presence of surface water that orbits with the mro is the atmosphere of Mars and the volatile Maven Evolution Mission, this cameralist spacecraft operates between 150 km and 6,000 km above the Martian surface measuring the composition of the atmosphere at different altitudes and observing how the tenuous gases are blown from the planet by the solar wind Mars Odyssey is the veteran of the Fleet in orbit that arrived in 2001 and is still operational in a polar orbit searching mainly for water ice on the surface Mars Express is a Space Agency mission Europe that delivers high-resolution photographs, menology data, near-submarine surface radar investigation and atmospheric measurements. including the search for methane, a gas that on Earth is associated with biological activity.

India's Mangal Yan space probe is primarily a technology demonstrator, but carries a secondary science package capable of investigating atmospheric composition. The latest arrival to Mars is the joint European Space Agency. Russian exomars. Trace gas orbiter that will observe seasonal changes in the Martian atmosphere and search for subsurface water deposits the spacecraft will form the communications bridge for the isa exomars rover that will land in 2021 the two most recent Mars explorers are the rovers opportunity and curiosity rover opportunity landed on plum meridian near the martian equator on january 25, 2004 with an expected lifespan of 90 earth days in a spectacular testament to jet propulsion.

Excellence Opportunity Engineering Laboratories remained operational until a planet-wide dust storm covered its solar panels in June 2018, after more than 14 years and a 45 km journey on the surface of Mars exploring the craters Endeavor and Victoria on February 13, 2019, the opportunity was finally declared dead. Younger and much bigger opportunities. Mars' companion is Curiosity, the most massive and most capable spacecraft to ever land on a planet beyond Earth. The landing itself was a huge engineering effort. Ingenuity and audacity.The enormity of the mission is best described through the words of Alan Chen, NASA operations lead for the Curiosity Mission at 10:31 PDT on August 5, 2012, watching The Landing in the jet propulsion laboratory next to To the team, the engineers described it as 7 minutes of terror. 7 minutes to maneuver a spacecraft that had taken 8 years to design and build and with a program cost of more than 2.5 billion dollars. 13,000 mph at the top of the Martian atmosphere to a soft landing on the planet's surface the tension reflected how high the stakes were for the Mars Science Laboratory's mission to give the Landron Orbiter its full title as a high-risk flagship science mission. in the same category as Voyager, the Hubble Space Telescope, Viking and Cassini, and was beset by cost and schedule overruns and controversies, in many ways this is not surprising, it is a new technology and an ambitious scientific goal.

The goals are difficult to implement and achieve and, in part because of this, offer great rewards. In retrospect, no one would question the value of any of these missions that have provided some of the greatest insights and most inspiring images in the history of exploration, but this never stops Bean from rival accountants and scientists with more charitable agendas and budget challenges of their own, and even considering cancellation, this is naive, funding for science is almost always reticent from a political class whose view of knowledge acquisition is utilitarian, the much deeper value of exploration as a critical part of the inner journey of our species that brings us into a direct confrontation with the mystery of our existence eludes them at least until occasionally the Johnsonian president (not Alexander Boris) at any moment may be, it may simply be that life as we know it with its humanity is more unique than many have thought and we must remember this, meaning that the cancellation of one project does not mean an increase in funding for another, the budget is more likely to be lost to science at the time of writing. , the same problems play in another NASA.

James Web Space Telescope flagship mission, as Robert D Bal wrote in an op-ed for space news in December 2008, at the height of the controversy over the Mars Science Laboratory implementing flagship missions, costs and overruns. calendar are not uncommon, but history shows that the mission returns frequently. dwarfs the expense, the Hubble Space Telescope experienced a development cost that exceeded its approved budget for the project several times and was launched much later than originally planned. In retrospect, wouldn't any rational space scientist admit that Hubble's return was worth the investment given February's atmosphere? However, no amount of philosophy or reason would mitigate the costs of the failure of the Mars science laboratory.

Mission: a landing accident was possible and unthinkable. Getting almost a ton of the fragile rover to the surface of Mars with millimeter precision is not trivial, which is perhaps why the engineering solution did not seem to put much stock in the fact that Mars has an atmosphere. thin, so slowing down a spacecraft when it's traveling about 10 times faster than a bullet is tough, and yet the atmosphere is thick enough to apply enough frictional heat to destroy a spacecraft without proper protection and turbulent enough to cause significant uncertainty in the landing site of an unsteered vehicle, this makes the most obvious engineering solutions redundant, you can't just deploy a parachute and float to the surface, the Viking Landers of the 1970s used a combination of heat. shields during parachutes to break arrows and retro rockets successfully, but the Curiosity engineering team discarded this proven solution because it did not allow for high enough precision or the soft landing required for precise delivery of a large rover with delicate wheels that They had the Viking Landers.

With legs built like tanks, the Viking Landers also carried their heavy descent rocket systems to the ground, which didn't matter because they stayed put. Curiosity would have had to carry all this unnecessary mass around Mars for years, the opportunity for Rover, its sister Spirit and the The previous Mars Pathfinder employed a combination of arrow-breaking parachute rockets and air bags to cushion the craft's fall. space, but these earlier Rovers were lightweight compared to just over a fifth of the mass of the gigantic curiosity: a Rover of this size and complexity bouncing across the surface in an airbag cocoon was not considered feasible primarily due to the large mass of the airbag system needed to cushion the impact, the opportunity to be lightweight, the rover's landing system was almost twice the mass of the rover itself.

The entry, descent and landing procedure chosen out of curiosity was described by Mission Leader Adam Steltzner as a result of reasoned engineering thinking, is a beautiful example of the truism that reasoned engineering thinking and common sense , at least the kind possessed by the average golf club driller, do not always match the curiosities that the untrained eye seems to see. It may be crazy or maybe too complicated, but it wasn't and it worked hidden inside a protective layer. Curiosity found the outer layers of the Martian atmosphere 125 km above the surface and traveling at around 20,000 kmph at 10:23 p.m.

Pacific Daylight Time on August 5, 2012, the spacecraft at this stage wrapped within a protective enclosure flew completely under the control of its onboard computers without any intervention from mission control on Earth. This was the first time that an autonomous guided entry system was employed for an interplanetary mission that used a combination of thrusters and balance mass ejection to change the center of mass and trajectory of the spacecraft and guide it with a precision of layout of around 10 km towards the chosen landing site. This guided rather than ballistic trajectory allowed a much wider choice of curiosity landing sites than for previous landers, which required around 100 km of flat, safe terrain around the nominal landing point, but also required that the rover will fly alone;

The round trip time for a radio signal to Mars was more than 13 minutes. When Curiosity landed making control impossible from the jet propulsion laboratory in California during the first stage of descent, a heat shield constructed of a unique material known as carbon ablator impregnated with phenolic P protected Curiosity from the peak temperatures of around 2000 °C generated by friction in the thickening. The Martian atmosphere, 4 minutes after beginning the entry phase, slowed to just under 3,000 kmph. Curiosity's parachute deployed at an altitude of 11 mm above the surface. The supersonic parachute is a vast and complex structure. 80 suspension lines more than 50 m long attached to a 16 M canopy that has decelerated to a speed of 700 km per hour with the help of the parachute, the heat shield was discarded at an altitude of 8 km, which allowed the onboard radar to obtain a view of the ground and provide high-precision altitude and speed measurements with the parachute fully deployed in a relatively dense low-level Martian atmosphere, the Curiosity floated in the Martian sky for 80 seconds, descending each time slower at an altitude of 1.8 km, traveling at a leisurely speed of 280 kmph, NASA's timeline demands a deep breath as Curiosity separates from the parachute system and free-falls toward Mars for engineers NASA's website says it's like jumping out of a plane for the first time.

Free fall was designed to allow Curiosity to separate far enough from the parachute system so that it doesn't accelerate toward it when 300 M below, its retro rockets were fired and the powered descent phase of the landing for the Viking Landers began. This was the final phase, but out of curiosity, after the Rockets had taken the Rover to an altitude of only 20 M with a descent speed of less than A 1 m/s, almost in hover, the bold final phase of the Landing protocol launched the sky crane, the rover slowly emerged from the rocket base held by three nylon cables and a 7.5 m long electrical connection umbilical cord, four of the rockets angled from the vertical, To avoid damage, the rover continued firing, allowing the entire delicate system to approach the surface at a walking pace of 5 M.

From the surface, Curiosity cleared its wheels stored for the 8-month journey from Earth at 10 :32 p.m. The rover confirmed that its wheels were in contact with the Martian surface and issued a final command through the electrical umbilical to the sky crane. I'm down, cut the cables and fly after a 500 million kilometer journey. Curiosity was safely delivered to Mars. 2.4 km from its nominal landing point, a triumph of engineering, ingenuity and curiosity were sent to Mars to explore Gale Crater, a 150 km wide impact crater formed in the late period Noan or early Beran period, when liquid water would have been present at least occasionally on the surface.

In the great tradition of astronomy, the crater is named after the Australian amateur astronomer, planetary observer, comet hunter and occasional banker, Walter Frederick. Gaale, who discovered a large number of comets as well as a number of geological features on Mars in the early 20th century. Using telescopes he built himself in his backyard, the main reason for choosing Gaale Crater was the unusual central structure of Mount Sharp or Aolis Mons, which rises more than 5 kilometers above the crater floor. There is still debate over exactly how Mount Sharp formed, but the layers visible from orbit along its flanks suggest that these are eroded remains of sedimentary rocks that once filled the crater and were deposited over time after the impact.

Subsequent erosion by the relentless Martian winds removed much of the surrounding rock to reveal the ancient crater floor once again. Leave the imposing central structure intact. Exposed deep sedimentary layers are extremely attractive to geologists because a cross section through rock is a cross section through time as surface and atmospheric conditions change. Different types of rock are deposited and chemically modified as the curiosity moves up the slopes. Mount Sharp climbs forward across Mars and scientists are closely following it Joy Crisp, deputy project scientist at NASA's Jet Propulsion Laboratory, explained the choice of landing site in the weeks before launch.

Mount Sharp may be one of the thickest exposed sections of layered sedimentary rocks. in the solar system The rock record preserved in those layers contains stories billions of years old about whether and for how long Mars may have been habitable, just as the rock layers exposed in the Grand Canyon of the Earth reveal the history of our planet. planet the exposed sedimentary layers of Mount Sharp are a storybook that the winds of Mars have opened ready for curiosity to read at the time of this writing. Curiosity has traveled almost 19 kilometers from its landing site on the plains to the lower slopes of Mount Sharp. stopping along the way at each interesting site to characterize the geological environment.

Curiosity's scientific instrument suite is the most sophisticated ever installed on a spacecraft. The Rover is a mobile geological laboratory capable of analyzing the Martian surface and the layers just below. NASA loves acronyms. Curiosity. acquires samples using the SSS, the scientific and surface sampling system, is composed of three parts, the sasar sample acquisition process and handling subsystem, Sam sample analysis on the Mars instrument and the chemistry instrument and Chemin minerals, the main components of sasar that is assembled at the end of Curiosity's robotic arm is an integrated shovel and sample processing system Chimera and a drill to acquire surface and subsurface samples.

The scoop and sample processing system surely have one of NASA's most inventive acronyms: C t h i m r, a pronounced Chimera after the Greek's many-headed creature. mythology that represents the collection and handling of the in situ analysis tool of Martian rocks, someone deserves a prize for transferring them to Sam, which includes a gas chromatograph, a mass spectrometer and a laser spectrometertunable and Chemin, the first X-ray defraction experiment ever performed. space and the most sophisticated modern technique for characterizing mineral samples on Earth science returned out of curiosity is just beginning as older data is analyzed and published and new data from its ascent up the slopes of Mount Sharp and through Martian geological time continues but they are current.

The results are consistent and greatly improve the detail of our image of a planet that was warmer and wetter when Gaale formed about 3.5 billion years ago in early October 2012. Curiosity piqued to locate the rock nest that the Geologists named and collected a handful of Mars, the sample of fine-grained dust and soil was introduced into the Sam and heated to 835 °C. The baking process revealed the presence of significant amounts of carbon dioxide, oxygen and sulfur compounds. Sam's analysis also suggested the presence of carbonates that form in the presence of water, perhaps most surprising of all is that the Rock Nest soil not only provided circumstantial evidence of ancient water: around 3% of the sample's mass It was water suspended like small ephemeral drops of salty liquid.

Curiosity is sitting on the floor of a Lost Lake. body of water that filled Gale on the Noan Hesperian boundary sedimentary deposit patterns suggest Lake Ro Rose and fell in multiple cycles over tens of millions of years a transient landscape of ancient stream deltas and ponds is bounded by the crater rim When An illumination on the ancient river beds that descend from the crater rim Curiosity has found sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon, all the components necessary for life. Summarizing the results in August 2017, Michael Mayor, NASA's lead scientist for the Mars exploration program, posed a fundamental question for this.

The mission is whether Mars could have supported a habitable environment based on what we know now. The answer is yes. In June 2018, two new discoveries strongly reinforced the idea that Mars was once a habitable world and perhaps still is. Curiosity found complex organic molecules a few centimeters below the planet. surface in rocks known as shales that form from silt deposited on lake beds, this means that all the ingredients for life were present at the time Gail Crater filled with water. Molecules detected include benzene, propane and butane. Even more tantalizingly, Curiosity also observed a strong seasonal variation in methane levels in the Martian atmosphere today, reaffirming and improving previous observations of methane spikes from orbit, the important additional information from Curiosity was that the methane reached its It peaked repeatedly in the warm summer months and decreased in the colder winter, which is what would be expected if the methane had a biological origin.

This is not irrefutable evidence of life on Mars today. It is thought that geological processes can explain such seasonal variation, although if this were Earth, a biological explanation would favor the appropriately cautious Michael Mayor said this in June 2018. Are there signs of life on Mars that we don't know about, but these results tell us that we are on the right path? Science is a humble and cautious pursuit and since Viking times, we have known that the chemistry of Martian soil is notoriously complex and can easily trap any scientist, so we should leave it there. Curiosity continues its journey through Martian geological history emboldened: it is indeed driving across an ancient lake bed where for a reasonably long period of more than 3 billion years ago conditions were favorable and all the ingredients for life were present, although we should not speculate or read too much into the results to date, we can let our imagination wander for a moment to imagine what Gail Crater might have been like in the late 19th century.

Noan, as life was taking hold on its sister world, we found ourselves on the shores of a lake that partially fills Gale, fed by runoff from snowmelt at the northern end, where Mount Sharp now stands, a small island broken The blue surface is not the mountain of today. but a small Central Peak remained as a result of the impact, a place of great beauty where every Marshan afternoon the pale sun sets in the west, beyond the island, the rays shining faintly on Still Waters, broken by the shadow of the peak to the edge of the crater. sphere that marks the passage of time in a lake populated by microbial Martians crater counting techniques developed from our exploration of the Moon allow us to place our observations of Mars today in a historical context allow us to construct an absolute timeline if We see evidence that water once flowed across a surface or collected inside a crater and we can date the area using crater counting, we can then estimate when the water flowed and when it disappeared, as we have discussed, the curiosity is Explore Gale and paint a vivid picture of what happened there.

The count allows an independent estimate of the rover's ground base measurements. A recent analysis using orbit images taken by Mro found 375 craters ranging in size from 88 M to 23 km within Gale Crater, implying an age of 3.61 billion years with an uncertainty of around 60 million. of years, this places the formation of the crater and the geological events that took place within it during the end of the early Noan Hesperian and this time period is consistent with observations of the presence of water at many other sites of a consistent age. similar during a A wide range of independent observations is extremely important in science.

A vision or set of observations alone can be tempting, but rarely convincing. Multiple independent observations reduce uncertainty and give scientists more confidence in their understanding when our goal is to understand the sequence of events on an ancient Earth. A distant landscape that no human being has ever visited. Caution and consistency are vital commodities as we currently only have one active rover and landings are, by nature, rare and confined to limited geographic regions. Orbital observations of much larger areas of the planet are vital. Tool MRO's high-altitude camera has provided some of the most beautiful and detailed high-resolution photographs in the history of space exploration, covering more than 99% of the Martian surface.

Features as small as a meter wide can be seen in these images and the camera can work too. In the infrared, which allows the identification of different minerals at the surface, there are many beautiful photographs in the MRO library that reveal evidence of persistent lakes and river systems, particularly across the No Aian terrain of the Southern Highlands. Sites like Jezero Crater clearly show the meanders. River channels that flow into deltas. Some images constructed using visible light and data from the spacecraft's spectrometer reveal well-defined river channels flowing out of the crater and the presence of carbonates and clays that form where there is persistent liquid water.

For these reasons, the Jezero crater. is one of the three primary goals of NASA's Mars 2020 rover. Some of the most recent finds are associated with the Arabia Tera region, which lies between Noaki and the Southern Highlands and the great northern lowlands, where water could have flowed into a possible Northern Ocean. Researchers from University College London and the Open University studied an area of ​​Arabia Terror equivalent to the size of Brazil using high-resolution mro images. The study mapped a network of more than 177,000 kilometers of ancient river channels, not the usual excavated dry river valleys, but rather a network. of inverted channels raised lines of sand and gravel deposited in river beds that persisted as the land around them eroded long after the rivers dried up.

Similar ghost rivers are seen in desert environments on Earth in Utah Aman and Egypt, where erosion rates are slow for identification. of the ghost rivers allows Arabia Terror to be identified as a fossilized flood plane, somewhat similar to the lower sections of the Ganges River on Earth, the lowland interface between mountain rivers and the sea, this is an important discovery because it feeds An ancient and still unresolved scientific debate about the nature of Noan's climate. No one disputes that rivers once flowed on Mars or that many impact craters once housed lakes. The key question is one of longevity: Was Mars warm and wet for long periods of time or was it mostly a frozen planet on which water occasionally melted, perhaps triggered by sporadic volcanic activity or changes in the orbit of the planet.

The tension arises because climate modelers find it very difficult to simulate an ancient Martian atmosphere thick enough to provide a stable climate for hundreds of millions. of years that would have been lost at a rate fast enough to produce the Mars we see today In a recent review, for example, Robin Woodsworth concludes that the weight of geoc chemical and geomorphological evidence points toward a late Noan hydrological cycle that was intermittent, not permanently active and The latest state-of-the-art Martian climate simulations suggest that an early Mars with water scarcity and episodic melting events may be a suitable paradigm for much of the later Noan and early Hesperian climate before the recent analysis of data from the Mars Global surveyor.

It was thought that there was a relative absence of river channels in Arabia Terror and this was interpreted as evidence that episodically wet frozen Mars ice may have been concentrated in the Southern Highlands and therefore lower elevations such as Arabia Terror may have generally been more arid and, therefore, deprived. of river channels, this appears not to be the case Arabia Terror was once very wet, in fact this debate does not have a consensus resolution at the time of writing, which reminds us of important points about our knowledge of Mars and science In general, we are describing and trying to understand and contextualize events that occurred more than 3.5 billion years ago at or around the time when life on Earth began, that is, an immense period of time during which the parameters orbitals have changed, solar output has varied, and countless impact events have created the planets that track the evolution of an atmosphere going back in time from current measurements based on geological and geochemical evidence from some landing sites and orbital images.

It is extremely difficult; suffice to say that there remains an unresolved tension between the small size of Mars and its great distance from the Sun and the clear evidence of an ancient The water cycle is either episodic or persistent, as Wordsworth writes in the introduction to his review of it. The nature of the early Martian climate is one of the major unanswered questions in planetary science. The complexity and apparent intractability of the mystery is reason enough for many scientists to study the character of Mars. from The Scientist requires not only comfort but also attraction to the unknown, acceptance and delight in the complexity of nature.

There is no simple history of any planet. Each of them is too big and too old, and some are subject to too many variables for us to ponder. What that means for our own existence as individuals and as a species: the specific fact of our existence is inextricably linked to the evolution of our planet through an incomprehensible web of cause and effect that traces back through major and minor events, many beyond Earth itself and filtered by The multidimensional civilization of evolution by natural selection connects us with all living beings that existed before, from the origin of life almost 4 billion years ago and the origin of our planet 500 millions of years before and the origin of the sun. system and the laws of nature who knows when maybe during the Big Bang or maybe infinitely far away in time there are many things we cannot know the search for certainty is foolish and the lesson is to find Delight in not knowing while simultaneously engaging to expand the domain of the known, that is the key to science, the key to happiness and the only reasonable response to the existential challenge of existence, because it is the truth, if you don't like that.

Take solace in the fact that the domain of the known The knowable is vast, possibly infinite, and perhaps, paradoxically, the knowable things on Mars may exceed those on Earth because Mars has been in a deep geological freeze for much of its life. It's moreeasy to investigate the deep past that on Earth and that deep past may include the origin of life The traces of geochemical alchemy that led to the emergence of self-replicating information carrying carbon molecules on Earth 4 billion years ago are long gone time, although clues can be found in the common structures and chemistry of living things today on Mars.

Geochemistry was frozen and archived in regions like Arabia Tera, so life began or still exists underground on Mars. Such a discovery may provide insights into our own origins that simply would not be possible by studying Earth's eroding and ever-changing ecosystems. This may be the gift of unknowable Mars - it is less unknowable than Earth - the Eridania region of the Southern Highlands may provide the most convincing evidence yet of a warm, wet early Mars with conditions no different from those on Earth. The analysis we describe below is a beautiful example of how the placement of scientific instruments aboard multiple spacecraft in orbit around Mars can be combined with our knowledge of the rate of crater formation. on the Moon to characterize an environment and trace its history through deep time, is also a beautiful example of the interconnected nature of science. and the value of exploration, we have already learned about the Moler elevation maps aboard the Mars Global surveyor.

This topological data, together with Mr. visual data revealing the location of the valley networks, suggests that the Eridania basin was once a giant lake, possibly the largest. It once existed on Mars at a depth of 1.5 km in some places and contains three times more water by volume than the Caspian Sea. On Earth we know that the terrain is around 3.7 billion years old thanks to the crater count that the Chism spectrometer on board the mro reveals the mineralogical composition of different areas of the Eridania basin and this can be used together with topological and visual data to build a three-dimensional picture of the landscape and its chemical composition in the deeper areas of the Eridania basin.

Eridania, magnesium and iron-rich clay minerals are common. deposited as talc sheets of saponite Serpentine and so-called tot clays, which are characteristic of seafloor environments on Earth. Materials known as iron-rich phyllosilicates are also observed, which again are characteristic of FL deposits from the terrestrial sea. The mineral jarosite is detected, suggesting the presence of chemicals. erosion of sulphite deposits there are many different carbonate signatures containing manganese, magnesium and calcium ions further up the basin walls. Chlorides are found that are indicative of evaporation in shallower waters. It is argued that the most likely explanation for the origin of the deep clay carbonate and sulfite deposits is volcanic activity at the bottom of a deep lake because very similar deposits are observed in hydrothermal sites on Earth, the iron minerals detected are similar to those formed in Earth's early iron-rich oceans before the release of large amounts of oxygen into our atmosphere through photosynthesis, all this beautiful topological, visual, geophysical and geochemical data can be combined to produce a picture of what was happening in the Eridania Basin about 3.7 billion years ago.

The geochemistry of the low-lying regions is indicative of a volcanically active hydrothermal environment in the deep sea with salt-rich deposits at higher elevations suggesting slow evaporation in shallower waters. The basin contained an iron- and mineral-rich ocean energized by active volcanism deep within the waves, a cauldron of complex geochemistry churned by the constant flow of energy from the inner planet. a surprising conclusion because, at the same time, a few hundred million kilometers across the solar system on Earth, many biologists believe that life began in similar deep-sea volcanic environments. The theory that life on Earth began in hydrothermal vent systems is common, although not universally accepted.

Either way, the idea is based in part on the observation that all organisms living on Earth today share an associated chemistry. with the establishment of gradients in the concentration of protons across membranes, known as chemiosmosis. Proton gradients are also characteristic of the geochemistry of alkaline hydrothermal vent systems in acidic oceans that were common on young Earth and perhaps young Mars, an analysis published in 2017 claims to have detected evidence of biological activity in rocks deposited by Hydrothermal activity at least 3.77 billion years ago in the Nua Guk crustal belt in Quebec, near the Ishua rocks of Greenland. The evidence comes from tube-like coils of the ion oxide mineral hematite similar in size and shape to structures established by ion-oxidizing bacteria in hydrothermal environments today it is possible that the rocks at Nook are much older a radiometric date using samarium neodymium The decomposition process suggests an age of 4.28 billion years, which the would make them by far the oldest rocks on Earth and a surprisingly early date for biological activity.

These findings are controversial, in part because of the difficulty of understanding how Earth's active geology has modified the samples over such broad time scales. This is where Mars may have an advantage over Earth in helping us understand the processes by which the chemistry of a planet became the chemistry of life. The environment in Eridania is much better preserved than that of Nuu AOK; It has been in sterile, almost frozen conditions for more than 3 billion years, the definitive laboratory for studying the origin of life, if life began on Mars. The history of the Eridania Basin and the possible scientific promise it holds were reconstructed using the results of different instruments on different spacecraft over many years spanning several scientific investigations. disciplines geology chemistry laser spectroscopy altitude measurement and photography surface age estimation required Apollo moon rock samples from 50 years ago and radiometric dating techniques that required an understanding of nuclear physics surface age estimation requires a model of the entire solar system to interpret the measured crater density, illustrating another important idea: the solar system is a system, no planet is an island, no planet can be understood in isolation, just as the structure of any living being on Earth cannot be understood in isolation.

Isolated organisms are the product of evolution by natural selection, the interaction of the expression of genetic mutations and mixing with other organisms in the ecosystem and the broader environment, the planets were formed in a chaotic fusion from movements as random as the impact of a cosmic ray on an Earth's surface. primordial DNA strand and any world The worlds that emerged from chaos have had their histories deeply shaped by their mutual interactions throughout their evolution. The intense late bombardment is a beautiful example, if in fact we discover that life began in the Eridania Basin, what a magnificent illustration of the unit of knowledge that would be understanding developed over centuries the life's work of thousands of explorers field geologists chemists biologists Astronauts Engineers distilled into the discovery of a second Genesis but more than that, due to the pristine nature of ancient environments on Mars such a discovery would offer insight into our own Origins that may not be available to us here on Earth Mars is a time capsule containing the frozen chemistry of an ancient world similar to Earth when life began, but while Earth's deep past has been largely erased 4 billion years ago. of GE iology in the action of a complex global living ecosystem that has transformed the planet and its atmosphere beyond all recognition.

Mars is a fossil from the deep past, this raises the wonderful possibility that another world, although an integral part of our system, could be the key to deciphering the mystery of the origin of life here the reason we exist is almost as if We would have to leave the Cradle to really understand it. About 3.5 billion years ago, changes were taking place on Mars. The warmer and wetter episodes that characterized the planet for millions of years during the Noan became less frequent and the climate shifted imperceptibly at first toward the coldest and most arid state we recognize today the water that flowed freely on the surface during the noan was locked in gigantic deposits of ice The lakes solidified and the rivers dried up the planet was not dying, much less the fireworks of the last intense bombardment had faded but the rumblings from the depths kept up the violence.

The shield volcanoes, including the mighty Olympus M, continued to grow even as global temperatures plummeted and underground lava flows occasionally melted. the ice deposits that caused catastrophic floods that defied the imagination in their scale and violence the age of Noah became the hesperion the age of floods or, rather, less portentously and more accurately, the age of occasional floods The Hesperian period is named after the Hesperia plum a Giant lava field northeast of the Helas Basin in the Southern Highlands. The plane was partly resurfaced by the volcano at its center Tyrus Mons and spans nearly 2 million square kilometers first photographed by Marin 9 in 1972.

It is a relatively flat landscape with few visible rocks. formations the most prominent surface features are the craters which allow us to date it Tyrus mons is a very different volcano than Olympus Mons and the giants of this is much older completely formed not long after the helicopter impact 4 billion years ago and entered into eruption frozen water or soil a process that produces large amounts of ash instead of lava what geologists call a pyroclastic eruption as a result of its age and composition Tire was more prone to erosion than the giants of this world and today is located just 1.8 km above Hesperia Plum The Hesperian period coincided with increased volcanic activity, particularly at this time, but there is not necessarily a causal link between volcanic activity and the transition from Noan to Hesperian.

What is clear is that volcanism became the dominant geological force on Mars as long-lived water cycles. Noan sulf form clays and carbonates in the more acidic atmospheric conditions created by the release of sulfur dioxide from volcanoes, while volcanic activity was the dominant force sculpting the softer Hesperian landscapes, spectacular and notable exceptions exist. in which the water reaffirmed its dominance, if only for a moment. echos chasma is an ordinary valley today the images taken by mro reveal a deep slope. Lateral depression located north of the Marin Valley, 100 km long, 10 km wide and between 1 and 4 km deep. It would be impressive on Earth, but it is dwarfed by the magnificent neighboring valley system from 3 and 2 billion years ago on frozen Mars Hesperius.

Things were different high up on this elevation, lava surged upwards through the crust and met large deposits of ancient ice releasing large amounts of water which descended from the Southern Highlands, meltwater was channeled into the chasma of echoes, where he created one of the shortest and most spectacular wonders of the solar system. The highland waters fell over the cliffs roaring 4 km deep into the valley. Over the largest known waterfall in the history of the solar system, around 350,000 cubic km of water cascaded through the valley, the equivalent. of a 70x 70x 70 kilometer cube in less than 2 weeks, being Hesperian Mars, the atmosphere was not substantial enough for the liquid to persist on the surface and the water disappeared as quickly as it arrived, leaving little evidence of the Great Falls etched into the canyon.

Walls Echos Casma was unique in scale, but the cycle of volcanic eruption followed by fleeting catastrophic floods was repeated in many places on the planet throughout the Hesperian; However, in the thinning atmosphere, the presence of liquid water was probably always fleeting, increasingly so as time went on, Hesperian became Amazonian around 3 billion years ago, give or take 500 million. years or so, when a Mars expert is asked when the Amazon began, they will usually saywhich depends on who you ask, but certainly two billion years ago, long before complex multicellular life existed. On Earth, Mars was virtually indistinguishable from the planet we see today, the Red Planet did not completely die.

Volcanic eruptions persisted and have occurred in the very recent past. There may still be eruptions in the future, but we know that Mars changed from a world that supported liquid water on the surface under a thick atmosphere through a period dominated by intense volcanic activity and episodic flooding to a hyper-arid icy planet with a tenuous atmosphere more in keeping with its small size and place in the solar system, this drama unfolded very roughly. During the first 1.5 billion years of its life, the challenge is to understand why the climate of a rocky planet is a dynamic system. complex formed by innumerable interactions, feedbacks and instabilities and inevitable changes over geological time scales.

A thin envelope of atmospheric gases can be dramatically affected. by volcanic and tectonic activity and impacts from space and on longer time scales by changes in orbit and inclination and changes in solar output The Earth appears to be a notable exception the most dramatic atmospheric change in the last 3 billion years has been the gentle introduction of oxygen According to pH photosynthesis, Mars today has a thin atmosphere composed mainly of carbon dioxide. We know that this atmosphere must have been significantly thicker in the past and possibly at even higher pressure than today's Earth because there was once liquid water on the surface.

They have therefore lost most of their original atmosphere and it is important to understand where it went and why ancient atmospheric carbon dioxide molecules could have frozen on the surface of the polar caps and become locked underground as carbonate minerals. or they could have been lost in space or some combination of the three to measure the composition of the current Martian atmosphere and understand how it evolved over time a dedicated mission reached orbit in September 2014 Maven, the Mars atmosphere mission and Volatile Evolution does not have high-definition cameras and does not provide dramatic surface photographs because the questions Maven was designed to answer are about the invisible envelope of gases that surround the planet if curiosity is the extension of our hands and our eyes .

Maven is our nose sniffing the air for clues about the past in which the spaceship operates. A highly elliptical orbit that brings it up to 150 km above the surface and beyond 6,000 km, this eccentric trajectory means that in each orbit Maven experiences a broad profile of the Martian upper atmosphere, allowing it to build a three-dimensional image of the gases. that still remain and how their distribution changes with altitude and time. Maven measurements show that Mars is losing atmospheric gases today at a rate of about 2 kg per second. The question is how the atmosphere is being lost and where it is going.

The Maven team carried out an ingenious analysis based on observations of the concentrations of two different isotopes of the noble gas argon (argon 36 and argon 38). Argon 38 is chemically identical to argon 36 but is heavier because it has two additional neutrons within its core The ratio of argon 38 to argon 36 is sensitive to the rate at which the atmosphere is lost to space through a process known as sputtering of high-speed electrically charged particles from the solar wind that strike atoms in the atmosphere higher and they literally throw them into space because argon 36 is lighter than argon 38 the relative abundance of argon 36 in the upper atmosphere increases in technical terminology argon 36 has a larger scale height than argon 38, this means that argon 36 is preferentially lost to space through sputtering and the ratio of argon 38 to argon 36 increases since there is no other way to remove argon from the atmosphere, it does not react with anything and does not freeze it anywhere near the observed temperatures In mars.

The argon measurements provide a very clear indication of how the Martian atmosphere is affected by the solar wind using measurements from Maven at different altitudes during its elliptical orbit and surface measurements of the argon isotope ratio from Curiosity, this Beautiful and elegant experiment allowed the team to determine that 66% of the argon in the Martian atmosphere has been lost to the planet's surface. Once this argon loss rate has been determined, the rate of other atmospheric components can be calculated. The published results concluded that evidence from Maven observations suggests that a large fraction of the Martian volatile inventory has been removed to space and that loss. to space has been an important process in the evolution of the Martian atmosphere over time, in particular a large fraction of the dominant component of the Martian atmosphere, the powerful greenhouse gas carbon dioxide, has been lost to space through from the interaction with the solar wind with a smaller amount.

The authors conclude that these changes appear to be large enough to explain the change in Martian climate inferred from the planet's geomorphology without decreasing levels. of greenhouse gases into the atmosphere to keep warm and protect its lakes and oceans Mars was destined to become a frozen desert world, but why hasn't Earth suffered the same fate? After all, we are closer to the Sun and bathed by a more violent solar wind. Why has our atmosphere survived solar attack for several billion years after the Martian atmosphere was stripped? The solar system is indeed a system, although we might feel isolated on a ball of rock in the dark.

That is an illusion. No planet is an island. The system evolves as a diagram is drawn of the food chain that supports all complex life on Earth today and at the base is a stream of photons generated 150 million kilometers away inside the Sun. Green plants They are the interface between a star and civilization. Our understanding of Mars. demonstrates that a planet's relationship with the sun is not just light and sweetness, the star can provide energy for life, but the solar wind can also destroy life or prevent it from emerging through the damage it can cause to planetary atmospheres. from which the solar wind emerges. the atmosphere of the sun known as corona the temperature on the surface of the sun is 6,000°C but the temperature of the corona exceeds one million°C heated by the energy transferred from the surface by the powerful solar magnetic field twisted and coiled by the rotation of the star in At such high temperatures the atoms cannot hold the electrons together. like plasma.

Some of these particles move so fast that they completely escape the sun's embrace and flow outward across the planet. solar system at speeds greater than 800 km/s this is the solar wind when these high energy charged particles reach Earth most do not collide directly with the atoms at the top of our atmosphere because we are protected by our magnetic field, they are Harmlessly deflected by stretching and distorting the field on the night side of the planet, the stretched field occasionally reconfigures itself by accelerating electrically charged particles back through the magnetic field lines to the Earth's poles, where they collide with atoms and molecules at the upper atmosphere, exciting them and causing them to move. emit light this is the Aurora, the northern and southern lights of the Earth, the Aurora can be seen by those lucky enough to be far enough north or south on the right night, when the sky is clear, the Sun is active and interplanetary magnetic fields are favorably aligned.

From the elevated vantage point of the International Space Station, the Aurora is revealed as halos dancing around the poles. It is an unforgettable site, undoubtedly one of the wonders of nature, but as is often the case in science and in life, the experience is greatly enhanced. For knowledge, lights that dance faster than the eye can see or perhaps the brain can comprehend are a direct result of the structure of atoms. Electrons switch between allowed energy levels determined by the number of protons in the atomic nucleus that holds them captive. Oxygen shines at high altitude. red an atom is struck by a charged particle accelerated along the Earth's magnetic field lines poleward the interaction changes an electron to a long-lived excited configuration if the atom is not involved in a mid-air collision during about 100 seconds an eternity in atomic At that time, the electron will move closer to the nucleus and a red photon will be emitted at lower altitudes.

A different reconfiguration within the oxygen atoms causes the emission of green photons. This time the atom must avoid collision for about a second, still an atomic eternity in the densest. Nitrogen molecules excited by the air add a deep red or pink to the lower edges of the towering light curtains during intense displays. This is quantum mechanics written in heaven. The structure of atoms is revealed to calculate colors. Physicists treat electrons as waves trapped within a deep atmosphere. Well created by the electrical charge of protons, particles imagined not as tiny flexes of matter but as fields that can span large volumes of space, the energy to power the screen comes from nuclear fusion reactions inside the Sun, a million-dollar factory. times the volume of the Earth.

Converting hydrogen to helium at a rate of 600 million tons per second, the weak nuclear force acts slowly and reluctantly to convert protons to neutrons in the central nuclear alchemy that results in the creation of neutrinos that flow across 150 million kilometers at a speed close to that of light before passing unimpeded through the entire planet on its journey towards infinity, therefore, 60 billion per square cm flows through your head every second without even a push because Your head is almost completely empty space and the neutrinos rarely get close enough to barely interact with the whole. Distributed Molecules May Happen Once in Your Lifetime Nuclear Forces Acting Inside the Sun Also Assembled the Heavy Elements That Make Up Your Body Inside Old Stars Long Ago From Hydrogen and Helium Forged in the First Seconds After the Big Bang Carbon Oxygen Nitrogen Sulfur The gravity of phosphorus and iron assembled the stars by forcing the collapse of the primordial interstellar clouds, causing them to heat up at their centers and triggering nuclear reactions that release the energy to stop the collapse for a few billion years, long enough for life to emerge on the planet. gradient between nuclear furnaces and the cold of the expanding Universe all these thoughts are ignited in the imagination by the display of the aurora our experience is enhanced by knowledge a central component of the network of physical processes that make the Aurora shine is our magnetic field that deflects the solar wind harmlessly beyond our planet and allows it to return in a much fainter form to the poles without this the processes that Maven observes stripping the atmosphere of Mars would occur on Earth the magnetic field is one of the Most important differences between our worlds The Earth's magnetic field is generated by what is known as a dynamo, which is easy to explain in general terms but extremely complex and not fully understood in detail.

The basic physics is simple. The Earth's core is largely made up of molten iron, which is a plume of electrically conductive fluid. of molten liquid rise and cool as they approach the mantle, and the Earth's rotation spins these columns into ascending and descending circulating flows. This circulating flow acts like a dynamo and generates a magnetic field. The stability of the dynamo is related to the temperature gradient between the core and the mantle, the radius of the core itself, the speed of rotation of the planet, and many other subtleties. The speed of heat flow through the mantle is affected by geological processes. including plate tectonics and volcanism the precise nature of the flows depends on the non-iron constituents of the core, for example the content and distribution of SU etc., its Fishlyn field gives every indication of be a delicate phenomenon.

It was certainly delicate on Mars. We suspect there was once a Martian Dynamo because the Martian crust is stillpartially magnetized in places. particularly in the ancient Southern Highlands, suggesting that these rocks cooled in the presence of a global magnetic field. The Helus impact basin that formed around 4 billion years ago shows no signs of magnetization, suggesting that the Dynamo closed before this impact. Impact basins that formed more than 4.05 billion years ago. years ago show signs of magnetization the martian meteorite alh84001 dated 4.1 billion years ago also shows clear signs of having formed in the presence of a magnetic field these observations lead to Baseline's current opinion that Mars had a magnetic field not very different from that of Earth, which appears to have shut down just before the Hass impact, from that moment on the atmosphere was exposed to the full force of the solar wind and the maven results tell us that this was probably the key factor in the loss of the Martian atmosphere, it would be tempting, but it is incorrect to suggest that the loss of the magnetic field was the trigger that drove the change from Noan to Hesperion.

The time scales probably do not match and in any case the loss of the magnetic field would not have led to an immediate loss. of the atmosphere sizzling as a gradual process that still continues today, there have been speculative attempts to link the Dynamo shutdown to the Hass impact or to multiple impacts around the time of the last heavy bombing. The idea is that mantle warming may At the time of writing, the sequence of events is reasonably well established, but there is no consensus on how, or even if, they are causally linked. A complicating factor is the relative instability of the Martian orbit; the planet's obliquity; the inclination of its spin axis varies tens of degrees on time scales of a few hundred thousand years in response to gravitational interactions with the other planets. planets and the Sun in comparison, the Earth's axis shifts smoothly between 22.1 and 24.5° in a 41,000-year cycle and even this small change is partly responsible for the Earth's periodic ice ages.

Imagine what happened to the Martian climate when the polar regions with their reserves of carbon dioxide and water ice were tilted towards the Sun by 20 or 30°. The stability of the Earth's axis of rotation is maintained by the damping effect of the Moon, which is unusually large in relation to our planet. The Earth-Moon system could almost be considered a double planetary system. The more we learn about other worlds, the more fortunate our presence on Earth will be. It appears that the Red Planet is simply too small, lost its heat more quickly than Earth from its smaller core, and, through its thinner mantle and crust, geological activity fell sharply after reaching a peak during the Hesperion and the Hesperion. planet faded, the atmosphere remained thinner than Earth because The planet's lower mass and its gravitational pull and unprotected by a magnetic shield was stripped away by the solar wind and the surface approached temperatures more consistent with an orbit away from the Sol.

The fate of Mars was sealed during its formation 4.5 billion years ago. Too small and too far from the Sun to have remained an active and vibrant world. Today, faint auroras still dance in the Martian skies, photographed by Isa's Mars Express spacecraft. Blue ghosts of a Martian past generated by localized magnetic points scattered across the planet and the last traces of carbon dioxide in the atmosphere energized by the relentless solar winds despite its three billion year existence Mars had a bright and active that resonates through the centuries and may yet have profound consequences for us, confined for now to its planetary neighbor, a solar system.

Over the course of a lifetime there may have been and may still be life on Mars we are searching intensely and the next generation of spacecraft may find evidence of Martians in the next decade the discovery of a second Genesis would have important philosophical, scientific and cultural consequences It would mean that given the right conditions, liquid water, active geology and a pinch of organic matter, we would know that life emerges with a sense of inevitability through the totally predictable action of the laws of nature, it would be a confirmation that we, along with all living beings on our planet today.

They are a consequence of the planet, an extension of geology, we would understand that any magic that we perceive in the depths of our souls has its origin in the interface between water, heat, minerals and gas, we are bubbling a chemistry that thinks that If it happened on two neighboring planets in a single solar system it happened everywhere we would understand that we are part of a great living Universe we are not children of God but we are not alone either of greater importance I think is the role that Mars must play in our future Mars is Rich in potential, it has reserves of frozen or even liquid water below the surface and a great wealth of mineral resources, everything that is necessary to sustain a civilization due to its history, this is a world in waiting, a Treasure Island in stasis, I believe that in my lifetime there will be Martians the Martians will be us we will go to Mars and make it our home partly because there is nowhere else to go Mars is the only planet beyond Earth that we could even contemplate a landing in the near future Marin's message because it was not interpreted correctly there is a second chance for us on Mars when we feel ready to take advantage of it.

I don't mean that we will leave Earth en masse for the new world. This is blatant nonsense, the Earth is by far and away the best planet we know of anywhere in the universe, we were born from it and sculpted precisely and perfectly to flourish on it through the action of evolution by natural selection, but now it is possible to build a colony on Mars. I imagine a group of pioneers. in the new world living off the land and building the infrastructure necessary for tens of hundreds and ultimately thousands of people to follow in their footsteps across the solar system and extend the human frontier for the first time in many centuries.

Frontiers are important, the intellectual frontier is the domain of science and where would we be without the pioneers who were drawn there the physical frontier is the domain of adventurous engineers and dreamers and dreamers need a place to go in Vana's film Herzog encounters at the end of the world a man named William Jerser describes the type of person who gravitates toward Antarctica, the last of Earth's frontiers. I like to say that if you take everyone who's not tied down, they all fall to the bottom of the planet, that's how we got here, you know, we're all loose.

It ends and here we are together. I remember when I first came here. I enjoyed the feeling of recognizing people with my travel marks. I thought, "Hey, these are my people, doctors washing dishes and linguists on a continent without languages. Mars is the step." Beyond Antarctica and maybe we all need to take it in our imaginations, our civilization feels free to me, we are at a loose end, huddled in a little corner of our system, watching the wandering planets and the spinning stars and the cycles of the day and night and we wonder what the hell we are doing, we are all linguists on a continent without languages, as a consequence we fight around eating up the Earth's increasingly precious resources, trying to expand and build more things and grow on a thin layer of air on the two-dimensional surface of a small rock without thinking about the three-dimensional path marked by the lights at night Robert Zubin, the visionary engineer whose work is inspired among others by Elon Musk, likes to say that ideas have consequences and the worst idea in the story of humanity is that we must compete for limited resources this is false the solar system contains raw materials beyond our or Desir's needs and they will become resources when we decide to access them the international tensions created by competition for resources terrestrials are Based on the totally false and dangerous idea that resources are limited false false false we have the technology and perhaps as we drift more and more aimlessly we can discover the will to unlock the limitless treasures in the vast solar system of which we are a part and that we need to change our Collective Consciousness, we burn too much for this world alone, but that does not mean that we must extinguish the flame, we must forge a new path that transcends the competition between nations.

That requires the total rejection of mentality that wrongly compels us to retreat or fight for dwindling resources on a single groaning planet, we must transform into a multiplanetary spacefaring civilization and this begins with the colonization of Mars, an achievable goal forged from human desire. explore and expand without crashing into someone else's border fence or damaging our planet beyond repair Imagine the magnificent intellectual and physical sights the new technologies the opportunities the excitement of creating a new society the joy of extending our collective experience, hopes and dreams to a new world and worlds Beyond Mars has a fundamental role to play in our future if we don't go there we will never go anywhere and if we don't go anywhere we will die here, breathing new life on the old red planet we will breathe new life For us it will be our first step beyond the cradle and towards the stars, the Earth before life was known 4.5 billion years ago.

The Sun could barely rise to signal the coming dawn. The planet was still shaking from an indirect collision with the Mars-sized Thea, now fragmented into a ring of debris that, over time, merged with debris ejected from Earth to form the Moon 4 billion years later. Two people who owed their existence to the energetic geology of Hadan Earth stepped onto the surface of the Coal rubble and considered their position in the sky from their point of view. Armstrong and Orrin saw a peaceful, pristine planet that has been many different worlds since its formation. Do we know how we can speak with authority about events that happened billions of years ago?

Beyond not only memory but also life on Earth itself. How do you calibrate that timeline? The answer is in the Rocks. Apollo delivered many treasures, countless engineering advances over a generation. The simple pleasure of exploration inspired the ascent of the Earth from Apollo 8, but scientifically speaking the treasure was Rock 382 kg of rock collected at six lunar landing sites on the Moon, since on Earth rocks can be dated with great precision using natural clocks provided by the radioactive decay of certain atoms, the chemical element rubidium, for example, occurs naturally and quite frequently in a form known as rubidium 87, which is found in many potassium-rich minerals, is unstable and It has a half-life of 48 billion years, which means that over a period of 48 billion years, half of the rubidium-87 atoms that were present in a rock when it was formed will have decayed and transmuted into another type of atom. of strontium 87 an older rock will have fewer rubidium 87 atoms and more strontium 87 atoms there is a little more than that of course How do we know how many rubidium and strontium atoms were present when the rock formed?

The smart part about the dating procedure is that we don't need to know it. The method called the isocon method is based on the fact that there is another naturally occurring form of strontium that is not produced by radioactive decay known as strontium 86. Strontium 86 is stable and chemically identical to strum 887, the only difference is that it has one more neutron. within its nucleus, this means that any strontium-86 atom within a rock today was present when Rock originally formed by counting the number of Rubidium-87, Strontium-87 and Strontium-86 atoms in a selection of samples taken from a rock, it is possible calculate the absolute time since the rock formed on Earth.

Some of the oldest crustal rocks are found off the southwestern coast of Greenland at a place called ishua using strontium ridium. We know that these rocks formed 3.66 billion years ago with an uncertainty of 0.06 billion years. The oldest known rock on Earth was found in Jack Hills, Western Australia. It formed 4.44 billion years ago with an uncertainty of 0.008 billion years all known samples of the Earth's crust are less than 4 billion years old because the boiling surface of the Earth hadan meant that the rocks were melting and reforming By constantly resetting radiometric clocks, the same analysis can be carried out on meteorites that have fallen to the Earth's surface from space, most of the more than a thousand known ones formed between 4.4 and 4.6 thousand ago.million years, which is consistent with independent estimates of the age of the solar system using, for example, Helium seismology measurements of the amount of helium in the sun. core The youngest of the lunar rocks returned by the Apollo astronauts was 3.2 billion years old and the oldest was 4.5 billion years old 12 of the samples were more than 4.2 billion years old The variation in the age of lunar rocks in the Apollo landing site is extremely interesting and important and if it forms the basis of the most accurate technique for dating areas of the Moon from which we do not have rock samples, we can make a graph showing the age of the rocks collected at each site landing site and also on the Russian Luna 24 robot. sample return Mission plotted against the number of craters per square kilometer at the site the dark spots around the labels of the various missions will represent the uncertainty of the measurements of the ages of The rocks and crater account for two very low and uncertain points from the The craters Cernus and Tao come from rocks collected by Apollo that are believed to have been thrown into the landing SES by impacts that created these two distinctive lunar craters in the much further past. recent.

Two solid lines curve across the graph delineating the oldest measured points. The sites have more craters, which is easy to understand because there has been more time for meteorite impacts to accumulate. Surfaces that were created in the more recent past, such as the Copernicus crater, have experienced far fewer subsequent impacts. Now imagine that there is an area of ​​the Moon from which we do not have samples but we do have photographs of that place from space we count the number of craters per square kilometer let's say we get an average of 0.2 craters above a diameter of 4 km per square kilometer this allows us to say that the surface formed approximately 3.2 and 4 billion years ago, similar in age to the Apollo 17 landing site, this is one of the simplest uses of the graph, the most important For our purposes, we can extrapolate the Moon graph to Mars, we have to do some modeling. dependent estimates on how the number of impacts changes because Mars is a larger planet with a stronger gravitational pole and to account for Mars' different place in the solar system, closer to the asteroid belt, the source of most of objects that impact, we can do this with some confidence and this is the main way we estimate the absolute age of different regions of Mars the Noan terrain is the oldest and has the highest density of craters followed by the Hesperian and the Amazon the northern lowlands have been resurfaced by volcanic activity in the most recent past that we know of because they are relatively devoid of anything much like lunar seas;

In this way, the absolute dates we cite for events on Mars are all ultimately tied to the radioactive dating of lunar rocks and this is one of the main reasons. why Apollo Rock samples from different landing sites are so scientifically valuable there is another key line on the graph a dashed line will be called constant production rate the number of craters plotted against age would follow this line if the moon had been subjected to a constant rate of impacts throughout its history measurements follow this line until we reach surfaces between 3,800 and 4,000 million years old, when the number of craters increases dramatically, implying that in the early history of the system solar there was a time when the rate of impacts was much higher.

Today, not surprisingly, we might expect the young solar system to have been filled with debris from planet formation and therefore a more violent place, but there is a complication if we assume that the impact rates observed in the older lunar terrain, such as Since the Apollo 16 landing site in the Decart highlands remained all the way from the Moon's formation, then the impact rate would have been incredibly high, the amount of mass that fell on The surface of the Moon would have been similar to the mass of the Moon. We know that didn't happen, so we assume that the rising impact rate curve on the graph is, in fact, a peak that peaked around 3.9 billion years ago and then returned to the rate of much lower impact than times before this violent peak.

In the rate of impacts from space it is known as late intense bombardment. The cause of the late intense bombardment is unknown, but one leading theory is that Neptune shifted its orbit from inside to outside that of Uranus and the resulting gravitational perturbation deflected a malstrom of icy objects in the distant Kyper belt toward the planets of the solar system. interior we could reflect on the interconnected nature of knowledge and the solar system Exploration of the Moon gave us the intellectual tools to date the surface of Mars using the scars left by objects deflected into the interior of the solar system by events that occurred far away in the space and time, beyond the orbit of either world, is a story that began before the solar system actually existed 5 billion years ago, a vast interstellar cloud of dust and gas at least 65 light years away. in diameter, that's 6.1 * 10 ^ 14 in kilometers, began to collapse and merge under its enormous weight, fragmenting into a collection of smaller dense cores, one of these gigantic groups formed what is known as the presolar nebula, the embryo from which each part of our solar system would develop in this dense cloud of gas composed almost entirely of hydrogen and helium, from which each atom would hang that would go on to form the Sun, the planets and each element that would define the character of each of these worlds, including the ingredients of Life.

The components of you and me that triggered This Cloud Past the Tipping Point and moved on to the next stage of its stellar evolution are lost in the eons of time, but surprisingly we have been able to gather fragments of evidence to guide us by studying some Of the oldest meteorites ever discovered on the Earth's surface, we have been able to glimpse the moment it all began. Locked within these ancient meteorites are the unmistakable signatures of rare forms of iron that we believe can only have been created under a very specific set of conditions. The only place in the universe where these rare isotopes can form is in the hearts of stars. short-lived giants at the very moment they explode in other words, they are the product of supern noi, this clear chemical signature of Rocks dating back to the earliest days of the solar system, more than 4.5 billion years ago, suggest that our The solar system emerged among a cluster of thousands of stars in a large stellar nursery, perhaps not unlike the Orion Nebula, the star-forming region closest to Earth. 1,500 light years away and can even be seen with the naked eye in the night sky