JPL and the Space Age: The Hunt for Space Rocks

Every day the Earth receives visitors from outer

space

tons of

space

dust that mostly goes unnoticed but sometimes larger objects can be seen streaking through the night sky. They are meteorites. Only a few of these shooting stars survived the fiery descent through the atmosphere. for having resisted their Their size is very small and they are given a new name: Meteorites, most of them are never found, but in 1954 a meteorite made its presence known in an extraordinary way. It happened in a small town in Alabama where Anne Hodges was taking a nap on her couch. When she woke up to a sharp pain in her left side, a meteorite had crashed into her ceiling and hit her.

It is the only verified account of a meteorite ever hitting a person. Of course, larger

rocks

fell from the sky fifty thousand years ago. A meter-wide asteroid crashed into the ground and vaporized in what is now the state of Arizona. All that was left was this 600-foot-deep hole, the best-preserved asteroid crater on Earth, and that's what happened to the dinosaurs 65 million years ago, that catastrophe. It not only exterminated the dinosaurs, but also three-quarters of all animal and plant species existing at that time. Tracking asteroids and comets is serious business and is an important aspect of the work the Jet Propulsion Laboratory does as part of NASA's broader effort to protect our planet from cosmic marauders.

They didn't have a space agency. Fortunately, we joined the search for space

rocks

. Asteroids and comets are as old as our solar system. They formed four and a half billion years ago in the middle of a rotating disk of interstellar gas and dust when the cloud contracted. our star, the sun lit up, you can imagine when the solar system first formed, it began as a giant cloud of gas and dust that begins to coagulate under the influence of gravity. begins to put it all together this is how the rocky planets Mercury Venus Earth and Mars endured incessant bombardment from other objects as they traced orbital paths around the Sun one of those collisions between Earth and a Mars-sized object gave us our most distant moon, The gas giant planets Jupiter Saturn Uranus and Neptune emerged, but even here there was likely chaos.

Uranus may have suffered a huge collision, one explanation for why it is permanently tipped on its side, the only planet in our solar system that exists in such a state, most of the mass ends up in the planets or the Sun, but there were left small pieces and eventually those pieces formed into what we know today as asteroids and comets, while asteroids are debris that reside primarily between Mars and Jupiter, the vast majority of comets are found far beyond the orbit of Pluto. A region called the Kuiper Belt is believed to contain millions of them, and much more distant, surrounding the entire solar system, is a celestial sphere.

The Oort cloud, billions of comets may reside here. It's from these distant places. places where some comets find their way to our planetary neighborhood, we now know that there is a kind of cloud of icy rocky bodies that are called long period comets or Oort cloud comets, these objects are probably remnants of the original gas cloud of which our solar system collapsed about four and a half billion years ago and are still out there. From time to time they make their way into the inner part of the solar system and can enter and then we see them as comets compared to asteroids with their dark surfaces. comets or boasts when a comet approaches the sun.

The dusty ice on its surface heats up and lights up, turning into a cloud of gas and dust that often has a tail that can be millions of miles long. To the ancients, comets were seen as harbingers of impending doom, but today fear has been replaced by fascination because these interlopers are relics composed of the oldest and most pristine matter in our solar system and it seems likely that we have them to thank for having brought to Earth a long time ago the elements that have allowed life to develop on our planet, we know for sure that a fairly large asteroid or comet is responsible for the extinction of the dinosaurs, so from that point of view they can be incredibly destructive, of course, we wouldn't be here without it, maybe we'd be walking. lizard people, I don't know, but it's true that life today is largely the product of an asteroid impact, a destructive one.

On the other hand, we believe that these objects have played a very powerful role in the potential to build life. On this planet and perhaps in other places, if we start from the beginning, which is the seed of an asteroid or comet, that small grain becomes a place where molecules can meet and form more complicated molecules so that they become places of nucleation for chemistry to occur so we can Let's start with simpler things, even like two hydrogen atoms, but eventually they build longer and longer chains of molecules, some of which can be very complex and eventually all of those complex chemicals can migrate to a planet, so we think comets and asteroids play a role.

It played for billions of years in seeding our planet with some of the chemistry it may have needed to eventually evolve life. The best known of all comets is Halle. It visits Earth approximately every 76 years. Its appearance in 1986 was a highly anticipated event. This was the first time since the dawn of the space age that it was possible to venture out and meet Hallie, and no one was more excited about that possibility than the then-new director of NASA's jet propulsion laboratory, Bruce Murray. Murray was determined to revitalize JPL, which he believed was becoming too cautious with missions that he dismissed as gray mice; he wanted the laboratory to create daring new technologies used to explore destinations that would excite the public.

He labeled these types of missions as purple doves because it would be impossible for Murray to ignore them. A mission to Comet Halle was commissioned, a once-in-a-lifetime event, but any spacecraft headed to rendezvous with Hallie would have to overcome a major challenge. Comets in general are in crazy orbits, there are similar retrogrades, some are very tilted, so they are not easy. goals to reach, especially if you want to reach and pass them fairly slowly so that you can study them in detail. Hallie's comment in particular was in an elusive orbit, so there were several proposals for how to get to the right targets. orbit Foreign's retrograde orbit means that it rotates around the sun in the opposite direction to the Earth's orbit.

A spacecraft flying over Halle would be like two cars speeding past each other, offering little time for exploration. Any attempt at Rendezvous and flying alongside Halley posed even greater challenges. but a radically new idea emerged: to design a spacecraft to be propelled by the pressure of solar photons from sunlight, similar to how the wind pushes a sailboat, so it takes an enormous amount of energy to reduce speed, when you come to a stop, you need a lot of fuel and The idea of ​​the solar sail is that you would need the fuel because you could use the change in solar pressure on the sail to manage your acceleration and deceleration.

That's what made it a really interesting, fascinating technology and also problematic because it's not something that anyone has ever done. Before it was really a science fiction idea, it was pretty far away and a lot of other people at JPL thought it was crazy. Two different concepts were proposed to capture the power of the Sun. The bolder of the two was called a helium gyroscope. structure that resembled a dozen helicopter blades stacked on top of each other every four miles long they had to use the sun to rotate up to 200 times per second in comparison the solar sail seemed almost conservative the astronauts had to deploy a sail from the space shuttle Razor-thin stretching half a mile long on all sides, Murray was so enthralled with the solar sail that he recruited colleagues, including his friend the popular scientist Carl Sagan, to help drum up support for a Halle Mission.

It was an effort that reached from the halls of Congress to Hollywood. Now what would I do right with this? It takes you where you want to go, so one mission that's being talked about is meeting Halley's Comet and I've always wanted to do it. No one has ever looked at an ordinary close-up and lives. mainly in the outermost part of the solar system, in fact, it lives mainly among the stars, it is a piece of interstellar matter and it would be great to find out what it is. Also, this thing itself is tremendously exciting because how it would be put together in the first place. in Earth orbit it would be bright enough to see with the naked eye through a pair of binoculars.

Solar sails and Helium Gyros were ideas well ahead of their time, but there was another purple pigeon whose development was beyond solar electric propulsion, also known as Ion Propulsion. Dr. Kenneth Atkins of the Jet Propulsion Laboratory described that The advanced propulsion system has an iron propulsion capability that is 10 times more efficient than our conventional chemical rockets and I believe this is what gives us the ability to achieve a comet encounter when ion propulsion is like the solar sail. He failed to gain ground. Murray later advocated for a sample return mission flying through Halle's tail to capture some of its dust and bring it back to Earth for recovery by astronauts.

It was another purple pigeon that never took off despite pleas from scientists. For the first time in history, our children could tell their children that they are citizens of a nation that, for the first time, didn't simply helplessly watch Hallie fly by, but actually came out to greet her and explore her in the end. It was the Soviet Union, Japan and Europe who continued with missions to find the comet, which became known as the Halle Navy, a space fleet without an American presence, but guided by two scientists recently arrived at JPL who were experts in the comet. tracking celestial bodies.

Our real fight in the next Halley missions was that we had to predict where the comet was, that was my job for the Soviets, for the Europeans, for the Japanese and then we ran international helicopter surveillance, which was the ground program to observe. the comet in the infrared in the visible region to obtain astrometric data of where the comet was at a given time. Halley's Comet was a kind of training ground for me, at least to generate and write software that could compute some of the interesting questions that were being asked. He particularly asked questions like how close Halley's Comet is to reaching Earth and so on in a face-saving gesture.

NASA repurposed and renamed a spacecraft near the end of its life and flew it past a comet, but there was no camera on board and it wasn't Halley's Comet, eventually Hallie disappeared from view just as that Bruce Murray, frustrated by what he believed was a U.S. retreat from solar system exploration, resigned as director of JPL four years before Halley arrived. Murray burned a lot of crests with his campaigns for purple pigeons and other things to save JPL and at the time, well, now it's NASA headquarters, he doesn't like it when centers go off on their own to try to promote what they they want to do and not what NASA headquarters is.

What was agreed with the White House should be done as long as none of Murray's purple doves took flight during his tenure, many of them would do so in the following years and, looking back, perhaps what was more important for JPL than sending a spaceship to Hallie was the lab's pioneering work in prediction. The comet's path to that achievement laid the foundation for JPL's future global leadership role in tracking near-Earth objects that could pose a threat to our planet and everything strange on it, seven years after Halley's visit. Three astronomers were searching at the top of Palomar Mountain in California. the night sky for comets, could you introduce yourself and tell me what you are doing there?

Yes, I'm Carolyn Shoemaker with a stereo microscope that was built especially for viewing our movies. Well, Mr. Shoemaker, what are we doing and what's happening tonight? Well, what I'm doing here is laying out our game plan for tonight. We'll probably shoot about 50 movies tonight. His luck had not been good for months. They had experienced bad weather and cloudy skies. It was snowing and it was almost the lowest level. point of all our years in Palomar, third consecutive monthWith virtually no observation during what appeared to be another disappointing night, the clouds briefly parted and rushed toward the telescope and captured a disconcerting image: It was an object near Jupiter, but it looked nothing like They wondered if it was a comet , simply a reflection of Jupiter or perhaps some scene from the Edge galaxy.

It turned out that astronomers Eugene and Carolyn Shoemaker and David Levy had discovered a comet and one like never before seen named after the three astronomers Shoemaker Levy 9. It turned out to be a comet that eight months before its discovery had broken into pieces due to to the gravitational influence of Jupiter and over the next month we learned that this comet not only orbiting Jupiter was very unusual for a comet, but it would impact Jupiter and it was It wasn't just one impact, it was 21 impacts because the comet had split into a pearl necklace and by the way, it was a real challenge to calculate the individual orbits for all those fragments and I was able to confirm that with the software I had recently developed.

Actually the first real impact probability calculation exercise was for Jupiter. This is a totally new event for the first time in the history of civilization. The history of the telescope we are seeing the impact of a comet against a planet because of this. We are mounting the largest single campaign, the largest observation campaign for a single event in the history of astronomy. The good news is that it is going to make a spectacular disappearance in Jupiter's atmosphere. The bad news is that it will do so on the wrong side. What Levy meant by the wrong side of Jupiter was that the fragments estimated to be up to a mile in diameter would crash into the back of Jupiter as seen from Earth and that meant that no telescope on Earth would be able to witness the actual impacts as they occurred, but on their way to Jupiter was JPL.

The Galileo spacecraft by mere chance Galileo would be in a position to witness the life of the impact. The Galileo spacecraft was en route to Jupiter and could look at the impact zone directly, while from Earth all impacts occurred at the back and rotated roughly into view. An hour after each impact, the crash sites would be visible from Earth, allowing ground-based telescopes to witness the aftermath. The enthusiasm in the astronomical community for such an extraordinary event quickly began to generate more sensational press. I'll be the Sun though, it's one of those tabloids that slips under your six-pack of coke on the way out and still says the comet crash will start the US Ice Age.

No government agency will verify the day imminent Doom, but sources say that's only because they want to avoid large-scale panic and unrest. the report of Mr. William Brock. I understand there are some members of the press here today and if Mr. William Rock is among them, I would like to speak with them after the talk. Please, amidst Yeoman's witty comments, they were actually very serious. implications computer modelers are going crazy there is a whole community of people within the DOD who do nothing more than model the effects of an impact, a nuclear detonation on Earth or an asteroid impact on Earth, the problem is that They don't have any data, so what?

They would love, of course, a 100 million megaton impact on Earth to refine their computer calculations. There are some obvious problems with that, so the same computer modelers are tweaking their code for Jupiter. I have another question here that we only had approximately. More than a year of warning of this event raised an interesting question: What do you think is the minimum warning time we would have for any comparable event on Earth? That's something we've been thinking about. An asteroid that is likely to hit Earth is one that we probably already know about and therefore, if the orbit is sufficiently well determined, we can simply integrate with the appropriate perturbations into the computer.

The exception to that, of course, are comets, long-period comets that can actually come out of the sun. We were surprised, but these appearances of long period comets are much less frequent than asteroids, but if a comet came out of the sun, it would catch us, they were stickers by surprise and there is not much we can do. to do about it, but it is a very low probability event, just as Chodes and Yeomans predicted when the first fragment of Shoemaker Levy 9 crashed into Jupiter's southern hemisphere on July 16, 1994. Scientists didn't know what to expect because they were just little dots with Tails and some were saying that these impacts would just fade away, we wouldn't even see anything and then shortly after the expected time for fragment a, we got a report that it was actually a bright spot on the surface of Jupiter, so was clearly visible and we knew that the day of the fragment was not one of the largest: a huge fireball erupted creating temperatures above 40,000 degrees Fahrenheit the plume would rise nearly 2,000 miles above Jupiter's atmosphere over the next six days at least 20 more fragments collided with the giant planet as we moved forward, some of the largest when they hit Jupiter were releasing, by some accounts, millions of megatons of energy when they hit, in part because they were arriving at high speed, but also because these fragments were probably at high speed. at least hundreds of meters in diameter each, so in your mind I think A is a kilometer-sized object, maybe E is A is one and a half and then G I suspect we're getting to within about three kilometers of what We're seeing.

It's not deep in the atmosphere, well the projectile hits deep and all the Hot Stuff burps up to the surface, so these effects we're seeing are above the normal atmosphere, they're above the ammonia cloud. The wonderful features that we're seeing here are something that has been brought up from the depths and was now deposited on top of one of these collisions with fragment G, which was the largest, and generated energy from something like 6 million megatons of explosive TNT, which is 600 times larger. the global nuclear arsenal if you were to ask what size crater would form on Earth, if we are right in our estimate of size and energy, if it hit a continent, a crater approximately 60 kilometers in diameter would form. coming out of that crater would essentially cover the Earth with a layer of fine debris that would simply block sunlight, simply darken the entire Earth, it wasn't hard to imagine the repercussions of such an event directed at Earth, but there wasn't much of a response from of NASA or the Department of Defense to address the problem that began to change four years later after a prediction that an asteroid could hit Earth in 2028 became front page news that it was a false prediction and the scientists who they made.

The prediction at the center of the minor planet was based on approximations. On the other hand, we were able to calculate the probability of impact and there was no chance of this asteroid hitting the Earth, so this became front page news in the New York Times and many other newspapers here we had a prediction that an asteroid could hit the Earth and another group, uh, Don and I said no, it can't hit, so there was massive confusion and I think this was a wake-up call for NASA at the time. In the wake of this media frenzy, NASA was responding to a directive from the US Congress to discover 90 percent of all near-Earth objects large enough and potentially close enough to cause global extinction. of life on our planet.

Today it is estimated that there are almost a thousand of these large objects around. 90 percent of them have been located, but there are many more smaller but dangerous near-Earth objects. So far, almost 5,000 of them have been detected and designated as enemies, that is, potentially dangerous objects. Most asteroid searching is done from the ground. telescopes, but determining their sizes and potential to cause damage is made difficult by the faint light these dark objects emit, but an infrared space telescope originally called Wise has been helping to fill this information gap. This was a mission to study the entire sky in four infrared. wavelengths of light, so longer wavelengths than our human eyes can see, and the mission goals were pretty simple: just make this amazing map of the sky with the goal of seeing everything at these different wavelengths. vibe.

It also turned out that this project was quite unexpectedly good at detecting asteroids, as it turns out that Wise was spectacularly effective at not only observing these objects but also discovering new ones after the coolant aboard Wise needed for stargazing ran out. It was renamed neowise and repurposed as an asteroid

hunt

er for an infrared telescope. do something that light-seeking telescopes can't do determine the size of an object. This is because we are measuring the heat coming out of the body, so instead of sunlight bouncing off the surface, we are actually seeing the sunlight being absorbed by the asteroid and then re-radiated as heat, so you can imagine that if we can measure the distance to the asteroid and we know its brightness at these infrared wavelengths, we can calculate how big It is because that is left out of the equations, but space the second life of the telescope is coming to an end now in development it is a successor mission now we are working on the near-Earth object reconnaissance mission this is a new mission of the NASA's goal is to really go out and map the entire population of near-Earth objects as completely as possible, in particular we're focusing on objects that are large enough to cause what I would call severe regional damage, which means which are 100 or 200 meters wide and that is equivalent to something like a 200 megaton nuclear explosion, which is pretty bad from my point of view, this is a fascinating problem for several reasons, one fundamentally it is a natural disaster that we can prevent through fairly simple means, we can literally look up and, if we do a thorough enough job, we can predict whether there is something heading our way or not, and even if the answer is no, everything seems clear , that's a very good answer, it means it's something we don't have to worry about, so from my perspective the solution is nice and neat. something truly wonderful and rare in science, comets generally have no qualms about making themselves known, but asteroids with their darker colorations are much more difficult to detect.

The first images of them were taken by ground-based antennas that use radar to create ghostly images like these. The first up-close visit to an asteroid came a year before the Shoemaker Levy-9 collisions, when the Galileo spacecraft was able to take a slight detour to capture some additional science. A NASA mission that had the sole purpose of asteroid exploration was accomplished by At the Maryland Applied Physics Laboratory, its spacecraft called near Shoemaker flew over one asteroid and then entered orbit around a second called Eros. This was the first time a spacecraft orbited an asteroid. After spending a year observing Eros, the team decided to boldly end the mission to attempt a soft landing on the asteroid, something never done before and something the spacecraft couldn't do. was designed to achieve such a feat, it required radar.

Scientific measurements provided by the JPL Deep Space Network and the experience of JPL navigators at this time. I just completed the latest set of navigation fixes, it is the latest optical navigation update and we provide that fix in case we want to very slightly adjust the timing of the next set of maneuvers and the group that has done the orbit determination for both close radiometrics. The use of Doppler radio tracking and optical navigation using landmarks on the surface of Eros are performed here in the jet propulsion laboratory. Yes, we are showing that the Doppler residuals are going down.

Alright. We are 1.7 from the landing site. Dave, yes. Let's now look at the range of inclination that maneuvers began as navigators and as mission designers. This is the kind of challenge we want. It's a very new, exciting and challenging type of mission for Rendezvous and asteroid and to try to touch it on the surface as gently as we can and I think we're certainly excited to find out what happens and how gently we can leave it. The images are truly spectacular, yes guys you can celebrate. Now it seems we reached less than two meters per second and survived long enoughAs for tracking on the surface we now have two lanes long we have a two lane lock after surviving the landing the spacecraft continued to operate for another two weeks an impressive end to an already successful mission.

Alright, the first spacecraft to fly near an asteroid. and Comet was a JPL mission whose purpose was not to chase near-Earth objects but to test a dozen advanced but risky technologies that larger, more expensive missions were hesitant to use. This was an effort to demonstrate that future projects could be smaller and less expensive. and capable of sometimes flying autonomously at the top of the list of innovations was ion propulsion, a technology pioneered by NASA's Glenn Research Center that years earlier had been proposed for a mission to Halley's Comet. Iron Propulsion is designed to give fast and flexible access to the solar system for Future Missions.

The first time I heard about it was in an episode of Star Trek, it was an episode called Spock's Brain for those of you who are Trekkies. and for me one of the interesting things about working on a project like this is that we are really managing to turn this fantasy into reality and that is very exciting. Mark Raymond, a self-proclaimed space nerd, decided when he was a child that he wanted to be a rocket scientist and was now living the dream after being handed the reins of the deep. space one, a spaceship that really looked like science fiction.

Ion thrusters use atoms of xenon gas that are shocked, the perturbation of which produces an electrical charge and the ions are shot out of the engine at tremendously high speeds, up to 90,000 miles. per hour, but because all of this occurs on atomic scales, the thrust is incredibly gentle and slow. Going from zero to 60 miles per hour will take deep space in four days. The thrust of our thruster is comparable to what I feel for the weight of it. A single sheet of paper in my hand, that's how hard the iron propulsion system pushes the spacecraft, but over time the thrust increases and ultimately we can reach very, very high speeds.

This is what I like to call acceleration with patients. The spaceship is also smart enough to know this. how strongly the Sun and the planets attract you and can actually determine where you go. I like to make an analogy about how powerful the combination of autonomous navigation with ion propulsion is compared to what we can do today. These two technologies are like having your car find its own way from Washington DC to Los Angeles pull into a designated parking space and do it all while getting 300 miles per gallon seven six green dash five of course deep space one first had to take off and that required a rocket to have a conventional propulsion system testing the spacecraft technologies of the next century within minutes of launch the high-risk billing of deep space seemed already in play when we launch a spacecraft we calculate where it will be in the sky and what time will its radio transmitter turn on and the signal didn't appear, that's not where you want to have problems on the overseas mission, there were many moreThere are more problems on that spacecraft than on other spacecraft I have flown since I just report again, you haven't seen anything download yet, a lot of things go into that because we're pushing the limits, we're building these things for the first time.

Favorite problems this moment in the flight The nervousness finally passes when the spacecraft reports that it is alive and well The team spends the next two weeks preparing to turn the spacecraft's eye on the propulsion system for the first time This was the big day in the one we were really going to turn it on, go to warp power, emit that cold blue ray and start flying with our powered flight 185900 Ace, this is the flight, go to India radiation Charlie zero one eight X-ray zero one in 1859 this is the moment that is expected to change the future of deep space exploration this will change to true it will go through the startup sequence so we had all these people here we sent the commands to the spacecraft and sure enough just In time, the spacecraft went through its own final procedures to start the engine. the engine worked great here we go everyone in Mission Control was all excited the people in the hallway were all excited it looks like we're on hold 20 recycles we're looking at uh the spacecraft had powered for four and a half minutes and then stopped, so we immediately began trying to diagnose the problem.

They filter themselves. It's noisy. There is a lot of crowding after regrouping. The team tries to restart the engine. Director. You are authorized to radiate the command. DSN file. Charlie uniform zero six five Alpha. zero one oh we have to inform you that the thruster went out again in the time limit and we turned it off and now we are in standby mode. Is there an evaluation of what, because of the sequence with that, is there a discussion right now about that? I am contacting you so that every time an arc occurs, the high voltage will be cut off and turned back on automatically.

That's right, several attempts are made, all with the same result. It's time for that to happen. Our spirits lowered. A little more ion propulsion was the main goal. Here we were unable to achieve more than four and a half minutes of thrust, and in fact our minimum success criterion for deep space was to drive with the ion propulsion system for 200 hours. Well, we still had another 199 hours, 55 minutes and 30 seconds to go. While disappointing, these types of stops weren't a total surprise. Similar events have occurred during laboratory testing because they should be cleaned up. There may only be a small piece of contamination left in the propellant in the ion engine, maybe from um.

Since launch, when the entire spacecraft shook violently, can you set up the times when we did a number of things, including rotating the spacecraft so that the engine was pointed toward the Sun and away from the Sun, which would loosen this particle so you could just walk away? After two weeks of using the sun to alternately heat and cool the spacecraft, the propulsion system was tested again. The era of ion propulsion had arrived during the course of the mission. We put it to the test. We tested it exhaustively. We showed that we could count. in it to power the spacecraft we can navigate with was wonderful, it meant that many later missions that would have been impossible without ion propulsion were possible.

What followed was a whirlwind of testing the other technologies on board and just nine months. After launch, when almost all of the mission's goals were met, the team was eager to fly by an asteroid called Braille, which was a great way to take all of these new technologies and demonstrate that planetary science could be done. We're there, let's use all this. fancy things to go take pictures of something the Braille asteroid was co-discovered just six years earlier one of the two co-discoverers was Eleanor Glow Helen a jpler and a pioneer in the search for asteroids finding the asteroid was an impressive feat for the asteroid It was so dark that deep space was almost unable to detect it and just hours before the encounter, a software error caused the spacecraft's computer system to overload, requiring a reboot.

The fact that the spacecraft was very temperamental almost made it impossible for us to make that encounter. We went into safe mode the morning we were supposed to do this flyby. I got a text back then, you know, we didn't have cell phones, we just had these pagers, but the pagers were fancy and you could get a text. I got this text saying we're in safe mode and I said, wait, the match is tonight. It takes three days to recover safely. Oh my God, I better get to work racing against the clock. The team transmitted new instructions.

The last order was transmitted with only a few minutes to spare. The scientific results were modest. The few images of the asteroid were taken at a greater distance than expected, causing them to appear out of focus. Still, this had been the smallest celestial body ever targeted by an approaching spacecraft. 17 miles, an impressive achievement that convinced NASA that the mission deserved a second try. The next target would be a comet, but in November 1999 the most serious crisis of the entire mission occurred: the Star Tracker spacecraft, which observes the stars to determine the orientation of the ship. stopped working without it, the spacecraft was left in a state of confusion knowing that neither up nor down nor right to left the star tracker in Deep Space 1 is responsible for telling the spacecraft how it is oriented in the zero gravity of space. , we know where it is and where it's going, but we can't tell where it's pointing without the star tracker, the spacecraft for all intents and purposes couldn't accomplish anything of value without the star tracker, there was no reasonable rational perspective of power continue the mission, but I didn't.

I want to give that up, easily normalize all of this to a number and decide what to add or subtract. The team began working on ways we could rescue spacecraft from the entire solar system with a fatal catastrophic failure for which there wasn't even a concept. How could we recover everything we had to work with was what was on board the spacecraft plus, of course, ones and zeros that we could send to it. They are followed by months of very, very long hours every day, constant stress, this feeling of you know what I want. To get this spacecraft back up and running, there ended up being only one possible solution: shipping new software that would reconfigure the spacecraft's camera to do double duty as a star tracker and camera.

The scientific camera was not designed to do that and had a much narrower range. field of view the star tracker has a giant wide field of view that can see a significant part of the sky the scientific camera is like trying to drive your car by looking through a soda straw basically what we needed to do from then on was to pick a direction we wanted to push find a star near there and then push towards that star for a while and then after a while the Navigators would tell us now we need you to point the push in this other direction like, oh , okay, let's go look for a star there that we can push like a sailboat sailing With the wind in deep space one zigzagged its way towards a comet called Borelli the closest approach would be September 22, 2001. 11 days before it was 9 11. the day the United States was attacked by four hijacked foreign planes, it just turned the world upside down personal emotions about it it was for God, we are going to achieve this, we are not going to let this stop us, the laboratory is Completely empty, there are guards everywhere with guns, you know?

There are guards with shotguns at the front door and you know we have special permission to be the only people allowed in the lab because we have this operations job to do. It was very emotional. He said many people had their American flags. IM volunteer. The JPL search and rescue team had an idea of ​​what was going on in New York, so I wore my search and rescue helmet that day, we had faced so many difficulties, we had had to make so many decisions and you know, in space deep had not been designed or built to find a comet and the encounter at Borelli did not go as we expected, instead it was perfect years of care over this damaged and injured spacecraft, it was quite rewarding, the scientists were elated with what were then the highest resolution images ever taken of a comet.

The dogged team of engineers could also take pride in having opened a new chapter in robotic space exploration. Later, when the spacecraft was running out of fuel and no other scientific destination was within reach, the mission was officially declared. today deep space won the small spacecraft operated by a small team with big hearts silently rotates around the Sun it's nice here we go during the same year deep space flew by the asteroid Braille NASA's first mission dedicated exclusively to the exploration of comets was underway the vehicle was not a balloon, although this was part of a critical pre-launch test, the main objective of this mission called Stardust is to send a spacecraft to capture samples of a comet and then bring them back to Earth , what has been ejected from the balloon is a model of the capsule that will contain the comet particles.

This drop test is to determine how hard the capsule can withstand landing. The landing area is The DugwayProving Grounds, a remote military installation in northwest Utah. The winter weather causes a cold. departure, but hopefully the moist ground will allow for a soft landing. They landed right on the road. A comet sample return mission was first proposed for Halley's Comet. The scientist involved in that original proposal. Don Brownlee had never abandoned the idea and the comet that it is. The comet came from the edge of the solar system, got to the inner part of the solar system where we are, and then we sent a spacecraft halfway to Jupiter.

To face this, it is really a kind of magical situation. I believe Vilt 2 is believed to be as old as our solar system and is believed to contain some of the most pristine and purest materials that exist in the solar system. What was a compelling case was made to greenlight the mission and the price did not hurt his chances of selection. This was one of NASA's fastest, best, and cheapest early missions. The goal was to fly a spacecraft for less money and on a faster schedule. and Stardust simply promised that the spacecraft is simple in design with few amenities and will be powered by solar panels, but no spacecraft has ever been asked to travel as far from the Sun using solar energy as this Mission will have to accomplish. and no spacecraft had ever flown as close to a comet as was planned for Stardust, so the spacecraft is front-loaded with bulletproof armor.

We are playing a game here, we want to get as close to the ordinary as possible to get the best images and gather the information. The largest amount of sample, but we don't want to be hit by particles large enough to destroy the stardust on the spacecraft. The most unusual feature of the spacecraft is its Comet dust collector. It looks like a tennis racket filled with ice cubes, but this blue material is an ultralight compound called Aero gel. Sometimes called frozen smoke, it is a solid that is 99 air. JPL researcher Peter Sue has made a career of finding ways to use this strange material, although it is very fragile but has a very high compressive strength and let me demonstrate this piece to you. of energy weighs about 10 grams this piece of plexiglass weighs about 50 grams that is already five times the weight this is a thousand grams this is another thousand grams is two kilograms so this is 2,000 times its own weight while Aero gel can carry more that its By its own weight, it is also porous enough to capture intact comet particles that move faster than a bullet a year after its launch in 1999.

Stardust collected the first two samples of interstellar dust and then moved on to a dress rehearsal of an encounter with a comet. The Anne Frank asteroid flight to protect the Stardust spacecraft remained at a safe distance of more than 2,000 miles. The engineers were delighted with the test and the scientists were even able to observe the asteroid from afar. A year passes before the encounter with Vilt II and as the day approaches, the comet is uncooperative, dimmer than expected, which likely means there will be far fewer dust particles to collect than desired when it comes to the brightness of the object, the photometry is somewhere between five-sevenths and five-tenths the amount of dust we expected to observe.

Yes, less light comes out of the object, this time there is less flux. The only way to collect more dust is to fly closer to the comet, but flying closer increases the risk of the mission being lost. Now, originally, we weren't going to use these observations to change our plans, we were just going to use them to confirm that we're still in the ballpark. This meeting offers a rare insight into how such lobbying decisions are made in real time. With just three days left on the table, our JPL navigator engineers, scientists, a representative from NASA headquarters and by phone spacecraft contractor Lockheed Martin, given concerns that debris blocking the comet could ruin the encounter or even destroy the spacecraft, the question on the table is how close in case the flyby is.

I didn't make a lot of noise about going to 300 at that time because there is a chance that we will lose all the images that we went into at 150. if we go in at 150 uh or so or close to uh, collecting the particles, but if we go that close, there is a four times greater chance that we will lose the image sequence during the flyby, so what scientific evaluation? But my recommendation is that we aim for 250, which is a modest correction, it is better than staying at our target value of 300 kilometers that we did in the past.

I'll use a simulated golf analogy, they're proposing the hole and we're making adjustments as we go and there's still a working probability, I mean it's not saying it won't work, it's just what do you mean, yes, but you mean probability, Well, I don't know, I'm not saying it's going to be absolute failure, I'm not saying it's going to be absolute success, you know, if we open ourselves up or expose ourselves to some new risk that we haven't imagined and that's really stupid, we will always be crucified and If we lose Closed Images, we take a gamble that we have always known. the comet could disintegrate at any moment it could go out it could turn on it's an uncontrolled beast okay I think another data point is independent of science, I won't support a 150 kilometer flyby, I'll be totally against it, so your recommendation is 250. 250.

After all this back and forth, the team agrees that the trajectory will be changed to bring Stardust 50 kilometers closer to the comet. If Build 2 has any more last minute surprises, there are contingency plans preloaded aboard Stardust that will hopefully allow the spacecraft to respond on its own Yes, we have a lot of static here Good morning, I'm Stardust Mission Control on the NASA's jet propulsion laboratory in Pasadena, California, is now one day after New Year's Day 2004. The time has also come for the comet's flyby. It's also just one day before JPL's opportunity rover lands on Mars.

It would be difficult to imagine a busier time. Its applications. We are going to an unknown environment. No spacecraft has come so close to a common. Is that consistent with the four-degree role we expected? see at the moment of closest approach Stardust is still sending a signal that it has survived the encounter, come on, life is tremendously good, we have been through the worst and we will still be in contact with our spacecraft soon. The spacecraft will transmit news that it has captured thousands of particles and, to everyone's delight, images of the comet. You've already seen these images.

The rest of the universe looks like this. You know it's true. Thank you. Nothing looks much different. It looks very different from what we hardly expected a kind of pile of rubble that looks like things just a dark black object broken charcoal briquettes or something like that it's a kind of soft and boring thing we were completely wrong vilt 2 was a much stranger object of what we imagined the comet's surface was dotted with towering pinnacles, steep cliffs, and strangely shaped craters. It was absolutely amazing. The first image we got showed these tremendous features now called left foot and right foot, which look like someone in a big clown suit just put their left foot and right foot on the surface of the comet now these are comet sized features. a kilometer that are hundreds of meters deep the flyby, although it had been much more dangerous than expected, dozens of planes had bombarded the spacecraft at a speed of a million particles per second like an erupting geyser The jets are explosions of material from a comet caused by the Sun's feeding.

We fly on these missions. It is possible to model everything we believe will happen. The closer you get, the more dust you will get. Maybe there are some big jets waiting shooting at us. and our prediction was no and we were proven wrong, quite wrong, but we survived with its abundance of comets and interstellar particles safely aboard Stardust, sandblasted but still resilient, began its two-year journey home, a Once close to Earth, Stardust will launch its capsule. It will have to endure the intense heat of re-entry through the atmosphere. A parachute will then deploy which should provide the capsule with a soft landing in Utah.

Helicopters will recover the capsule and then this cosmic cargo will head to a laboratory. at Johnson Space Center in Houston for detailed examination, that's the plan, but a parachute didn't open on another JPL mission called Genesis. His capsule containing samples of the solar wind crashed into the Utah desert. Fortunately, enough particles survived the harsh landing to be useful to the scientists, but no one wants to see a repeat of such a devastating experience. After a seven-year, nearly 3 billion-mile journey, the capsule re-entered the atmosphere at a speed of nearly 47,000 miles per hour, the fastest re-entry of any human. -Recorded object witnessing the spectacular entry where scientists flying aboard a NASA Ames Research aircraft, the Blazing capsule filled with comet particles now appear to be itself a confirmation of the comet.

Stardust was the first sample return mission since the Apollo astronauts brought rocks from the Moon to Earth inside the capsule containing thousands of comet and stardust samples that were shared with scientists around the world. These particles, the only known samples from the outer solar system, were once part of a primitive ice-rich body that formed far beyond Pluto, but surprisingly many of the rocks. The dust particles were similar to those found in primitive meteorites that formed near the Sun. These particles were apparently transported to the distant comet-forming zone in the outer regions of our solar system. Another discovery was the presence of the amino acid glycine, a fundamental component of the Its detection of life has added credibility to the idea that the materials necessary for life to arise may be scattered in abundance throughout the Universe, while Stardust brought back samples of the surface of a comet.

JPL's Deep Impact mission was designed to crash into a comet in hopes of revealing what materials reside inside five four three two one we have the ignition and liftoff of a Delta II rocket carrying Deep Impact NASA's journey to unlock the mystery of the origin of the Solar System and the air begins to light up being launched into space are actually two Deep Impact Mothership spacecraft and its cargo a small impactor the size of a washing machine that will be launched to collide with a comet. The two spacecraft were built by Ball Aerospace and JPL was responsible for overseeing the management and creating the especially complex software needed for the mission we had 12 months to complete.

Complete the assembly of the Prime spaceship. Complete the assembly of the impactor spacecraft. Review the entire environmental testing program. Repair flight software. Repair fault protection. Fix all the mistakes we found along the way and discover in parallel how to hit the comet. a comet was something no spacecraft had ever done, and to have any chance, computer simulations needed to be created at JPL. More often than not, the first simulations were unsuccessful and then, two months before launch, an almost catastrophic mistake was made. There was that black day in November when Someone came in and accidentally deleted all the footage we were working on for after launch.

It all happened one night deleted because someone thought it needed space on a server and it was like how the hell can we recover from this? It was working intensely for long hours and the pressure did not ease after launch. The trip to the comet called Temple One was short, only six months, when only halfway there the comet was already in sight. The JPL flight team barely had enough time to settle in. Before the encounter occurs, it normally takes many months to launch a spacecraft and test everything in flight and learn its idiosyncrasies and get everything calibrated and working well, so launch the spacecraft in only six months from of then having a The meeting was very challenging we were sleeping in our offices level of hard work and I came one day, you know, to my office and I had my bedding ready and someone had rejected my sleeping bag and had put a mint in my pillow and I left a little note that said complimentary turndown service and it was, uh, yeah, they were crazy, crazy days and what Deep Impact was expected to do sounded a little crazy too, which has been described as hitting a bullet with a bullet after the impactor is released.

The onboard navigation system has to visually find the comet to execute three homing maneuvers.Free possibilities to focus on the comet. The impactor once we release it has an automatic navigation system like the one we introduced with deep space and it locks onto the comet. you try to make sure you're going to get it right and you make that first correction based on information from very far away, so each successive correction as we get closer will be better and smarter, so there wasn't a lot of real information. All of this will happen on the 4th of July, but the Comet Temple, not one to be outdone, has already been setting off its own celestial fireworks.

Comets are known to sometimes have sudden outbursts that release massive amounts of gas, ice and dust that briefly increase their brightness. One concern is that if Temple One decides to explode during the encounter, the impactor's automatic navigation system could become confused; In the worst case, the impactor might miss the comet completely. what the team wants to happen on a national holiday turn all subsystems of the impactor spacecraft green right now it's the 4th of July it's 90 minutes until impact thanks to the first trajectory maneuver of the impactor or it's on march impact flight impact CM Thruster shoot with accumulated times increasing the copy thanks clay confirm your good radiation attempts they look as expected, they accumulated on time it is also correct and we will give you a more complete report later Daddy, thanks the comet still It's not done with its surprises.

Right now it's the comet, that's why we're going there. It presents us with a very strange shape. We've been watching it all day as we get closer. We initially thought this was something of a pickle as we got closer. It looks more like a banana and the last resolution we have in the rotation that's going on is that we're looking at the ending and the ending is basically triangular, so it all depends on what that comment does and what kind of face it gives us and we have we have to figure it out so that's the challenge and it seems like this has been quite a temperamental comment over the last few days we've seen several outbursts yes that's right we've seen it. the explosion of the real jet that illuminates it, so it is very exciting for scientists and distressing for engineers and, even worse, the results of the first maneuver of the impactor were not what was expected.

It was the largest motion outside the comet we have ever seen. Even more than any of the simulations, the knowledge raises the possibility that a deep impact may miss the comet entirely, and there's starting to be talk that everyone is really worried about whether we can correct that and get back in in less than a second at this point. Go ahead, I would like to add information to that deep line by saying that we are approximately one kilometer from the ground uh navigation solution. It was an extra pair of hands, so I basically moved around when problems arose, as it turned out.

That first correction took us into the weeds a little bit, they're aware of it and they're worried about it, but they also think it's supposed to bring us back. It was hair-raising after itm2, which is equivalent to 31 meters per second of flight. fly in thermal let's go offline for two minutes, damn, sitting next to me, he looks like a ghost because all the blood is leaking out of him and he says: watch out, I need to go off the grid for a few minutes, you know, he goes off the grid and then he comes back five minutes later and looks better and you know he leans over to me and whispers saying I just threw up because I was so sick because of how big I was and I wasn't sure if we would have come.

Whether we come back or not, we can't do anything about it, all we can do is trust in the work we did. We saw the comet in all three cameras. We have seen it in the impact chamber. The two cameras aboard the flyby spacecraft. In addition to providing live commentary during the event, Don Yeomans Yeomans is unaware of the concerns about the trajectory maneuvers, but he has his own reasons to be anxious because they needed some Stooges to come out and talk to the media, whether it was a resounding success or a horrendous failure, so I was very concerned to receive this question after the fact that, as you know, Dr.

Owens, NASA has spent 240 million dollars on this Deep Impact Mission and you missed it, so this is our best image to date. It's going to get much, much better now it looks bright, but it's actually a very jet black object that's being overexposed to show the light. It's rotating around an axis that's more or less up and down, from what you're looking at. the small end of the problem here is a Nine Mile problem, just so you remember, that's right, we have started shooting the itm3 flight for the itm3 copy, the last of the three Thruster Burns is underway, it can't be done nothing more, the mission is shown in public Tech, we are going to record in our last state change enabled for goodbye, final images before Shield mode, we have a performance disable of all adcs, basically we are left with what keeps the hardware talking , the adcs, you are on your own copy, there are some of the images that come.

From the spaceship, oh look, it seems that we no longer have a pickle, but an eggplant. Yes, we are now moving from pickle to eggplant. Here it looks like we have some clear surface features there. to the right, a dark depression, maybe look at the Jets, look at all the Jets, yeah, I have a little voice in my ear telling me we can put the impact camera image on our monitor right now, okay, this one it's the place in the impactor image where we're headed for impact the spacecraft is doing remarkably well for something that's about to vaporize it's getting closer maybe taking some serious dust hits our brave little spaceship is in our environment very hostile here not only are we going faster than a speeding bullet we are going about 10 times faster than a speeding bullet and that puts Superman to shame.

We expect to lose the spaceship at any moment, but it's doing a great job. Just before we check it out, this is Mike, this is Telecon, we've lost the block copy, I mean, my God, that's incredible. Congratulations, the mother ship flying below the comet recorded the consequences, the impact was much more dramatic than expected, generating a bright flash of light, an immense fluffy cloud. of ice dust and gas that the surface of the comet was extremely fine weaker than powdery snow it was a big surprise this was not an ice cube comment a crater and an ejector that is considerably brighter and considerably more material was released from What I thought was also unexpected.

The considerable amount of organic material that was detected is yet another indication that comets and asteroids may have provided the early Earth with the building blocks of life. We have all the data we could ask for and the team scientist is ecstatic, we can believe they are Getting paid to have so much fun, there was more fun the next day, The Comets, Bill Haley's original backup band in The Comets, were on a nostalgia tour and made a surprise visit to JPL to offer his musical congratulations. News of their presence spread quickly. and soon a spontaneous celebration broke out.

These comets were bobbing before there was something called a space age and they still knew how to make a stunning impact on their own years before, after Voyager's last planetary encounter, the legendary Chuck Berry had played this same spot now jplers could too brag about having rocked out to the sounds of the first rock and roll band thanks deep impacts impacter was no more, but the mothership had survived and the team was eager to sign up for another mission five years after the one the temple encounter deep impact flew for a second comment partly also JPL's Stardust mission was also reused.

He revisited Temple One to see the aftermath of Deep Impact's collision with the comet and Deep Impact was followed by NASA's Goddard Dart mission. The spacecraft flew toward a small Moon orbiting an asteroid to demonstrate how they could deviate slightly from their course. Tracking asteroids and comets is an international effort. A Chinese lunar orbiter flew past an asteroid on the European space agency's Rosetta mission. with the JPL scientific instrument on board it achieved the first mission to deploy a lander on the surface of a comet and NASA's New Horizons mission has bragging rights as the most distant object ever explored after its flyby of Pluto after JPL's innovative sample return missions The Japanese space agency has gone a step further with its Hayabusa 1 mission landed on an asteroid collected small grains of material and brought them back to Earth, the Japanese repeated this remarkable achievement for the second time a decade later.

NASA's Osiris-Rex mission has also collected samples from an asteroid now on its way home, scheduled for destination in 2023. Technological advances from JPL's Deep Space 1 mission were used on the laboratory's Dawn mission using ion propulsion. Dawn was able to orbit two worlds in our solar system for the first time. Vesta and Ceres, the largest objects in the asteroid belt recently launched is NASA's Lucy mission, which is to visit asteroids that share the orbit of Jupiter and Psyche A spacecraft managed by JPL will soon be on its way to an asteroid made not of rock or ice but of metal flying a spacecraft powered by a solar sail finally succeeded in 2019 with the planetary society small light sail spacecraft 2 this publicly funded mission remained in Earth orbit for three years before returning to enter the atmosphere NASA's recent solar sail mission could not be deployed All of these missions try to learn more about asteroids and comets so we can better defend against For them, one element of planetary defense is called mitigation.

What could be done if a near-Earth object threatened our planet? There are many mitigation ideas. Place a solar sail on the asteroid. Throw rocks from the surface. the asteroid and the spaceship and by pushing on the space grid you could move the asteroid from its earth impacts, of course if you had enough time there is the impactor which is my favorite because it is very simple and fast. The mission and the Deep Impact mission demonstrated the fact that we can hit these targets if necessary, in the worst case, if you had a large object and little time, you could use a nuclear explosion.

It's like the '98 Armageddon movie. We have to bring back Bruce Willis, but the three most important things. to mitigate a possible impact on Earth are to find them early, find them early, and find them early before they find us, and a recent example of that need occurred in 2013. It was a year in which it was known that an asteroid called 2012 da14 would be passing by. extremely close to Earth, a very close approach and it was going to go inside the Geosynchronous Satellite Ring, so it's very close, it's almost scary in the sense that you want to see if it will hit any satellites, but we knew it wouldn't.

We hit and we had been following this for about a year and predicting this approach, so it was an event and we had a NASA television show presented here at JPL where we planned to talk all about the approach, nothing to worry about . it's getting really close and these things are weird but we know it's not going to hit now da14 is not a threat it's not going to hit earth scientists say the closest it will get will be last night which should happen but on youtube all these reports. of a massive fireball in Russia in the city of Chelyabinsk, many of the videos were from dash cameras and showed a really massive fireball that was clearly much brighter than the sun, making it a major event to be reported.

It became evident in our little story of a The asteroid that came very close to the satellites was being fully anticipated. Well, right now I'm joined by Paul Chotis and Paul. We probably have to address this meteor that hit Russia overnight from the beginning. What an exciting day we have. We feel like we are in a shooting gallery here we have two rare events of near-Earth objects approaching Earth on the same day, what can you tell us about this? At this point, first of all, the two events are not related, the meteor over Siberia and over Russia was not related to the asteroid 2012 ba and they are not on the same trajectory or in the same orbit, it is simply a coincidence that they hit and approach Earth on the same day.

How big was this meteor? The meteor we believe was about 15 meters in size, which is about a third the size of da14 itself, okay, so it's much smaller, much smaller and you can see what kind of destruction and shock wave it can produce. a smaller asteroid. It's like Mother Nature is showing us what a small asteroid can really do. It is estimated that the energy released was equivalent to one500 kiloton TNT explosion, many times larger than the atomic bombs used in World War II. The shock wave blew out windows, damaged buildings and caused more than 1,500 injuries, including reports of skin burns and temporary blindness.

Why was this asteroid not detected? The answer was that it had approached Earth from the direction of the Sun. looking towards the sun is a blind spot not only for our eyes but also for telescopes to have had advance warning of The Chelyubinks meteor would have required detecting it in a darker part of the sky the last time an event like Shelia Banks occurred was more ago a century, but the fact that an object so small, believed to be no more than 50 feet, can cause such damage is yet another warning issued by Mother Nature because there are likely millions of near-Earth objects still remaining. this same size to be found, so how should the world prepare for the possibility of a major impact by a near-Earth object in the future?

Several United States government agencies participate annually in practical exercises in which they must react to the impact of a fictitious near-Earth object. The realistic schemes are devised by the JPL Center for Near-Earth Object Studies. The brain to create these fictional Doom threats is the center. Mild-mannered Paul Choudes, the conference is called the planetary defense conference. They've been going for 15 plus years, almost 20 years in each of these, we usually have exercises where we ask ourselves what if, and many of these, I've done. Put together scenarios of an asteroid hitting Earth and simulate that and calculate what we would know when an exercise in 2021 begins with a new asteroid of undetermined size discovered by a ground-based telescope - it's about 35 million miles away.

At about a third of the average distance from the Sun, the discovery is transmitted to the minor planet center in Cambridge, Massachusetts, which collects and catalogs small solar system objects. News about the asteroid is then transmitted to JPL and we collect that data as we go. that usually all of this is automated, so we would calculate its orbit as accurately as possible and the uncertainties in that orbit, which would initially be enormous, and we would determine whether or not there is any possibility of impact now for this particular scenario, which impact is of only six months. away and therefore our software would immediately detect the fact that this could hit the Earth.

We need more observations as it happens so it's pretty good, a time frame of just six months is dire news but initial calculations show the probability of an impact is low at about one chance in 2500. but to have some confidence In this estimate more observations are needed, so depending on where the true trajectory of the impact is for a week, astronomers around the world point their telescopes at the night sky and with each observation the chances of an impact increase continue tracking us. It gives an increasingly better idea of ​​whether it could impact or not, but there is the other question of knowing well what the effects of that impact are and that depends on the mass of the asteroid, which is basically its size, but we never really know its size precisely. unless we have something like radar or visit it with a spacecraft and take images of it.

These two options are not feasible. Radar is only effective when an asteroid is close to Earth, by then it will be too. late and with the impact only six months away, there is not enough time to launch a spacecraft for close observations, so virtually nothing will be known about the size of the asteroid and the damage it could do to the Doll Racer. , this Corridor allows me to progress through a Many of these things, at the end of the first week, the probability of the asteroid hitting the Earth has increased to five percent or one chance in 20.

As for where the asteroid can occur impact, the potential areas at the beginning are literally all over the map. Covering two-thirds of the Earth's surface, large swaths of the Earth are initially at risk and it is our job to get an increasingly better orbit to reduce it so we know where the asteroid is going and can isolate the region from the Earth. where things could get worse over the next few days new observations with ground-based telescopes are not possible due to the glow of the full moon astronomers are taking advantage of this time to search their archives for possible past signs of the asteroid buried in meanwhile, for policy makers An important question is what information should be shared with the public and when the data on which we base our orbital calculations are truly international in scope and available worldwide and the other orbital computers can run their calculations may not be as elaborate as ours, but they get similar results, so it would be very difficult to sit on this impact prediction and not tell anyone that the group suggested that the headline makes no bones about it: a newly discovered asteroid poses a risk to Earth. the impact in six months passes another week the effort to review the past data has borne fruit shows that the asteroid had gone unnoticed seven years before with this orbit data in hand a better prediction of the trajectory of asteroid flight the news is not good, the probability of impact is now 100 percent.

Potential target areas are also shrinking. A new owner is being prepared. New observations confirm that the asteroid will impact in six months. The regions at risk are Europe and North Africa in this particular scenario with only a few months of warning. It's really impractical to think that we could deflect this particular object, so this scenario was designed more or less to address the civil defense problems of what would be done to evacuate areas once you knew more or less where it was impacting and once If you knew more or less its size, if the asteroid measures up to 160 feet, the impact is expected to be as powerful as the atomic bombs used in World War II.

If it is a thousand feet in diameter, the destruction would be measured on a continental scale, half a mile wide. asteroid could mean a global catastrophe. Meanwhile, an international effort has been exploring how a space mission could protect Earth. We talk about it. You know what we could do to mitigate and if there would be a chance, but with six months there isn't much, it soon becomes clear that there is. There is not enough time to attempt a deflection technique that could throw the asteroid off course. The only option left is to attempt to launch a spacecraft armed with a nuclear explosive device, and since so little is known about the asteroid, the recommendation is to send a bomb of the same size. the best possible and then hope for the best, of course this assumes that a spacecraft capable of rapidly arming itself with a nuclear device is possible.

Such a rapid response capability is currently not known to exist, while observations by the Infrared Space Telescope again provide the first information on the size of the asteroid is probably no more than 500 feet in diameter. The impact zone has been reduced to a region mainly within Germany, Chechia and Austria. Cities at risk include Munich, Prague and Vienna. There are now six days until the asteroid hits 4 million miles away. far away and now within range of JPL's radar. The asteroid's size imaging assets are further refined: It is between 300 and 400 feet in diameter. Estimates of how powerful the impact could be range from 9 to more than 150 megatons to give those numbers, meaning a single megaton contains the equivalent of a million energy. tons of TNT arrives on the day of impact the asteroid enters the atmosphere at the precise moment predicted the world can only wait for what will follow today we know more than a million asteroids in our solar system and thousands are found each year the majority reside in the asteroid belt between Mars and Jupiter and pose no threat from that place of concern are the asteroids that are closest, especially those that can cross Earth's orbit.

It is believed that 90 percent of the near-Earth objects that could cause a global catastrophe have been found, but there are estimated to be thousands of asteroids large enough to cause serious damage over a wide region that have not yet been identified. discovered, but that knowledge doesn't seem to keep asteroid

hunt

ers awake at night. These events are so unlikely to happen that it is not something we can actually do. In fact, I feel more confident in the sense that we have the capacity to deal with them. Through the tabletop exercise there was one big takeaway: greater awareness of the extreme challenges that come with a late discovery, the conclusion of that exercise is that that asteroid could have been found earlier, at least seven years earlier, with a better study of asteroids, a more sensitive study, like adios of hair, if a system of With more robust detection including an infrared space telescope, this fictional asteroid could have been known years earlier.

Given a number of mitigation options, there could have been time to build and launch a reconnaissance spacecraft to determine the composition, mass and size of the asteroid. asteroid. With that knowledge, an action plan could have been devised to deflect the asteroid, then what is the best line of defense. the answer is worth repeating: the main goal in defending against the closest objects around Earth impacting your trajectory is to find them early find them early and find them early before they find us strange strange strange