A Natural History of Mars

About 3.7 billion years ago, a little north of the equator, a flash flood swept a large rock into a fast-flowing river and swept it downstream into a delta. Where the river met a lake that had formed inside a huge 45 kilometer wide crater at the impact site. from an asteroid that had hit a long time ago, the rock eventually splashed into the crater lake and sank to the bottom. Floods like this were quite common on ancient Earth, but this wasn't Earth, this was Mars, but at a time in the deep past when it was much more. Like Earth, it had large bodies of liquid water on its surface, it had a protective and insulating atmosphere, it had a warmer climate, and perhaps it just had life as far as we know, although it no longer has any of those things here.

Over the eons, we often talk about the radical changes and countless revolutions our planet has undergone over time, but while Earth's

natural

history

has unfolded over the past billion years, another saga Epic planetary has been developing right next door, even though we've been asking questions about that red dot in the night sky for a long time and have recently started to find some answers thanks in large part to our curiosity and perseverance. So, what happened on Mars? How and why did it happen from there? warm, wet, potentially habitable planet, to the cold, dry, inhospitable planet we know well today, the main reason seems to be that, while we had some surface level similarities at an internal point, Our Two Worlds were on very different trajectories , strange things to many different people over time.

In human

history

, the ancient Greeks counted this strange moving point of light as one of the planets or Wanderers and its foreboding reddish tint meant that several ancient cultures interpreted it as a divine symbol of the violence and conflict of war, but it wasn't until Galileo for the first time. We observed the planet through a telescope in the early 17th century, Mars began to mean something very different as astrology gave way to astronomy, our views of Mars transformed from a mystical celestial body to an actual physical place, a Completely different world, complete with vast geological features.

The landscapes we could see were mapped out and we dreamed of visiting and it also opened the door to another tantalizing possibility when we looked at Mars. If we didn't have the technology to get good answers, it would take until the second half of the 20th century, when our relationship with Mars was transformed once again, for us to finally investigate this possibility because Mars went from being a place we could only observe from very close range. away to a destination we could actually travel to or at least ship machines on our behalf. The Landers orbiters and now the Rovers have revealed to us a dry, rocky world with no obvious signs of life and have also offered us the long-sought After the opportunity to gain new insight into the planet's

natural

history, let's take the Perseverance Rover, for For example, our most recent robotic representative to arrive at the red planet since 2021, Perseverance has been working on a very important mission to explore and study the now dry lake.

That crater bed that we mentioned earlier here is looking for evidence of any ancient life that might have called that crater lake home billions of years ago and the data that Perseverance has collected has also allowed us to trace ancient geological events from that period. most dynamic of The History of Mars, like the story of that flood almost 4 billion years ago, back then the planet had a thicker atmosphere and was much warmer, wetter and suitable for life, but to understand how and why Mars changed to what it is today, we must go back to its Formation see The history of the origin of Mars was very similar to that of Earth, with some important differences.

Both planets formed about 4.6 billion years ago from clouds of dust and rocky debris that orbited our sun at their centers. There were partially molten iron cores that gave both planets powerful magnetic fields. It was the result of the Dynamo effect, the generation of a magnetosphere by rotating convection that acts and electrically conducts the liquid iron in the outer core. Now we are lucky to still have an active and powerful magnetosphere here on Earth, more than 4 billion years later, it acts. like an invisible shield that protects our atmosphere from erosion by the charged particles of the solar wind expelled by the Sun, but Mars has lost its magnetosphere and with it the protection against those solar winds, over time they took away its thick atmosphere, its heat, its protection. against radiation it is liquid water and it looks like it may have once had life too because the Mars Dynamo went out sometime after 3.7 billion years ago, we can say that because those are the youngest Martian rocks that are still magnetized, which What happens when lava cools in the presence of a magnetic field?

We're still figuring out exactly why it went out, but a large portion of it may have simply shrunk in size. Mars is only about half the diameter of Earth, so its core cooled much faster after the planets formed. This turned off the Dynamo effect. and exposed the atmosphere to the full force of solar winds, planets, rivers, lakes, and perhaps even an ancient ocean disappeared when water froze, became trapped in rocks, or was lost to space without a thick atmosphere. that retained it, although they left behind the Valleys Beds of lakes and coasts that they carved into the planet's surface Primary objectives in our search for past or present Martian life because the question is whether life would have emerged during that era of habitability long ago, Could some especially resistant lineages have stayed, perhaps moving underground? or to the polar caps where, after all, there is still a certain amount of liquid water.

If the study of life on Earth has taught us anything it is that life finds a way and species, especially microbes, can often adapt to thrive in even the most extreme environments, or else. Could any evidence of past life have survived after all those billions of years? While we haven't found any definitive evidence of Martian life, we have still found some clues in 2018, for example, Perseverance is Big Brother's Curiosity, made an intriguing discovery, collected data showing that the concentration of methane in the thin atmosphere of Mars (a gas that on Earth is produced primarily by living organisms) appeared to have seasonal cycles, suggesting that the gas could be leaking from underground reservoirs, which could potentially be a byproduct of microbial life below the surface, where there could be liquid water and where there is better protection against radiation, in addition, both curiosity and perseverance have also found a variety of organic molecules in Martian rocks on the surface that are more than 3 billion years old.

All life we ​​know is carbon-based, so organic molecules are the necessary raw materials and possible traces of ancient carbon-based life are now unclear. None of these discoveries mean that life definitely used to exist on Mars or still exists today. Both could also simply be the result of chemical and geological rather than biological processes. We don't know for sure yet, but there are basically three possible options: Mars never had life, Mars had life at some point but became extinct, or Mars had life and still has life today, and discovering it might even require another transformation in our relationship.

With the Red Planet, we may have to bring Mars to us by returning some of the most promising samples to Earth. We could study them in much more detail than our Rovers alone on the planet itself, so in late 2022, Perseverance carried out one of its most important orders, collected a sample of rock from the crater, packaged it in a tube of titanium and left it in a nearby assigned location. This was the first of many samples of rock sediment and atmosphere that Perseverance has been tasked with carefully collecting, and a robotic mission will arrive in the early 2030s that will recover some of the samples and return them to Earth for analysis.

Scientists hope that studying real samples from Mars in our laboratories from that ancient crater lake and other promising sites could be the key to solving the question of life on the planet whatever the answer will radically change the way we understand the nature of life itself is by biology common or rare in the universe life on Mars is related to life on Earth is that life based on the same underlying biochemistry and genetics or a completely In other words, in a different system, Are there other ways to be alive? Is life infinitely resilient, able to adapt to even the most difficult times and persist in some form, or can a planet lose its entire biosphere, down to the last microbe, if conditions get bad enough? and you can see how answering these questions, especially the last two with data from Mars' past, could be important for the future of life on Earth.

Those curious about the microcosm join host Hank Green and Devoki Shock Rivardi in another program produced by our Journey to the team. microcosmos if you haven't seen their videos yet, you are really missing out each episode uses incredible images to immerse you in the small invisible world that surrounds us, check them out on youtube.com microcosmos we know that Mercury, Venus and Mars are all have very little water So why do we have so much? Find out in our episode where the water came from and thanks to this month's Marsing eontologists Raphael Huss Jake heart 1M Annie and Eric Higgins John Davidson ing Melody lamb Carnival and Colton become an ionite on patreon.com for eons and you can profit funny like sending me a joke to read.

Here's one from Sarah W. What are animals' favorite basil herbs? And as always, thanks for joining me on Adam Low Studio, please subscribe on YouTube. com eons for more prehistoric stories both planets formed about 4.6 billion years ago from clouds of dust in rocky debris or to surprise see Marge's March