In short
Perseverance rover’s “leopard spot” rock in Jezero Crater may be a biosignature—organics plus minerals on Earth linked to microbes—while the episode explains how scientists search for ancient life on Mars and why sample return to Earth is crucial.
Guests (backgrounds)
- Katie Stack Morgan, NASA Perseverance project scientist; coordinates rover science and led/participated in the team’s biosignature plausibility vote.
- Lindsay Hayes, NASA astrobiologist; discusses the history of Mars life speculation and how to interpret evidence.
- Mandy Nguyen, podcast producer; visits the Mars Yard at JPL to see Perseverance testing.
- Morgan Cable, Perseverance research scientist; works on PIXL instrument for elemental mapping.
- Camden Miller, rover planner/“rover driver”; schedules and guides rover operations from Earth.
Key claims
- Leopard spots are unusual white spots with dark rims; data suggest organics and two minerals plausibly linked to microbial activity.
- Not definitive proof: non-biological processes could create similar minerals.
- Best path to certainty is bringing samples back to Earth (sample return planned after 2030).
Notable examples
- ALH 84001 “fossil” debate (structures later argued to be geochemical).
- Mariner 4 (1965) showing Mars lacks canals and is harsh.
- “Seven Minutes of Terror” landing and PIXL’s x-ray fluorescence mapping.
Written by AI. May contain mistakes. Listen to the episode to check what was said.
Chapters
Tap a time to open that second in VOExploring Jezero Crater and the Potential for Life
1:00 to 5:30
Learn about NASA's Perseverance rover and its quest for signs of life on Mars.
“In the summer of 2024, NASA's Perseverance rover was exploring Jezero Crater on Mars.”
Historical Perspectives on Life on Mars
5:30 to 8:01
Explore scientific history and the evolving beliefs about life on Mars.
“200, 150 years ago, if you asked the average person who understood the concept of planets in our solar system, you know, do you think that there is life on other planets in our solar system?”
The Quest for Ancient Life on Mars
8:01 to 11:10
Understanding the potential for ancient life and the challenges in finding it.
“Mars is still the most similar surface environment of any planet or of any body in the solar system.”
Perseverance's Journey and Rock Selection
11:10 to 14:01
Follow the Perseverance rover's journey and how scientists choose rocks to study.
“But the best way to figure out if there is some life preserved in those rocks is to get those rocks here on Earth.”
Exploring Mars: The Perseverance Rover
14:01 to 17:44
Learn about the Perseverance rover's mission and testing process on Earth.
“and then blasted away so it wouldn't fall on top of it.”
Rover Navigation and Communication Challenges
17:44 to 21:50
Discover how rover planners manage navigation and time discrepancies on Mars.
“Even though Perseverance can navigate to a specific spot on its own, it still needs constant guidance from scientists and engineers like Camden to determine exactly where it should go.”
The Quest for Martian Life: Evidence and Samples
21:50 to 22:31
Understand the significance of rock samples in the search for life on Mars.
“for us to really be confident that we have made what I think would be civilization-level science of finding out for the first time in human history that we're not alone.”
The Quest for Martian Life: Evidence and Samples
23:50 to 24:09
Understand the significance of rock samples in the search for life on Mars.
“It can help you with practically anything on the web, like restoring a vintage motorcycle from a 50-page restoration block, or finally break down that long article you've had open for weeks.”
Implications of Finding Life on Mars
24:20 to 28:00
Examine the potential implications of discovering life on Mars and its connections to life on Earth.
“So you went on this really fun field trip, and I'm just jealous.”
Exploring the Potential of Martian Life
28:00 to 29:44
Discover the implications of finding ancient microbial life on Mars.
“we really get really close to the question of all questions of how does life start?”
Show all 12 chapters
The Journey of Sample Return Missions
29:44 to 31:35
Learn about the challenges and timeline of returning Martian samples to Earth.
“Someone needs to send a rocket to collect those rocks and bring them back.”
The Human Connection to Perseverance
31:35 to 32:50
Understand the significance of the Perseverance rover and its human connection.
“When I think about perseverance on Mars, I think it's really easy to think about it as a lone rover traversing the desert landscape, the rocky red, you know, ground.”
Transcript
Automatic transcript. May contain errors.0:00Morgan Cable:How many third-party vendors does your company use? 20? 200? Thanks to AI, someone on your team probably added three more this week. And your security lead has no idea. Traditional third-party risk management can't keep up. Vanta gives you continuous coverage across every vendor, automatically, so you actually know what's in your stack and what to do about it. AI on, risk off. Vanta.com slash TPRM.
0:34Morgan Cable:You might need MIDI if you ever hairsprayed your bangs into a waterfall or tried to go for a run with a CD player. If this was you then, you might need MIDI now. Perimenopause can start 10 years before menopause. If you're experiencing symptoms like night sweats, weight gain, or anxiety, speak to the menopause experts at MIDI Health. Book a virtual appointment at joinmidi.com. Midlife needs MIDI. Results may vary. Medications prescribed only if clinically appropriate based on a consultation with a clinician. In the summer of 2024, NASA's Perseverance rover was exploring Jezero Crater on Mars. So you could set the scene here.
1:14Morgan Cable:It's the site of an ancient lake. It's not there anymore, but there once was a lake here. Katie Stack Morgan is the project scientist of the Perseverance rover, which is kind of like the brain that coordinates all the different parts of the operation. And in 2024, they sent Perseverance in to investigate a little outcrop of rock in the crater. And when we got there, the outcrop, I would say, didn't look particularly unusual. I mean, rocks on Mars are shades of red and gray and often pretty dusty. But as the scientists went through some pictures Perseverance was sending back, they noticed an unusual rock.
1:56Morgan Cable:We see in the images these totally weird features that we call leopard spots because they look like leopard spots. What is otherwise a red rock has these little white spots in it. And each of the white spots is surrounded by a dark rim. And we thought, whoa, I mean, this is unusual. You don't see this in most rocks that you look at on Mars. We had some of our scientists look at these leopard spots and say, hey, this looks like a kind of feature that I recognize from here on Earth. and it's one that involves microbial life and it's found in sediments like what we're seeing here in the channel. And so that got sent around and said, hey, you know, these things, if they form on Earth, typically have a biological origin.
2:45Morgan Cable:And as Perseverance sent over information like chemical analysis of this rock, scientists found more tantalizing clues. The data suggested that there were organics like carbon and two specific minerals that here on Earth can be the byproduct of tiny living microbes. It was all pretty exciting. We were like, whoa, okay, like we've got organics, we've got this interesting chemistry going on. So we actually took a eyes closed, heads down vote of the science team to see whether people thought this was a potential biosignature. So fortunately, I got to see because I called for the vote. So I got to see what happened, and there were a lot of hands raised in the room.
3:30Morgan Cable:So, intriguing. Now, if life did create these minerals, it probably did it something like three and a half billion years ago. We do not currently have an expectation that there is life in these rocks today. And this remote analysis of the leopard print rock is not definitive proof that there was once microbial life on Mars. There are, for example, other ways that these particular minerals could be produced without life lending a hand. But this month, a peer-reviewed paper came out saying that it is at least plausible that this leopard print could be a sign that life once lived on Mars. It is potentially a biosignature, a trace left behind, like an old dinosaur footprint or a fossilized worm burrow is a trace of ancient life here on Earth.
4:24Morgan Cable:The best way to get more certainty would be to bring samples of this rock back here to Earth, where we could then study them more closely. If we bring these samples home and we find evidence of life in them, I mean, I think I will have considered myself having contributed something worthwhile to humanity. But until then, this is still a pretty cool step towards maybe finding alien life out there. There are a lot of things about this job, working on a rover mission, that are like any job. But then every once in a while, you get kind of like pulled out of that. And then you're like, oh, wow, the things that I'm working on have the potential to, you know, change paradigms for how we think about life in the universe.
5:12Morgan Cable:Here at Unexplainable, we have been interested in Perseverance's quest for a while now. And so in light of this new finding, we wanted to share an episode from our colleagues Brian Resnick and Mandy Nguyen all about the search for life on Mars.
5:29Camden Miller:For ages, scientists have looked at Mars and just wondered, anybody home?
5:36Katie Stack Morgan:200, 150 years ago, if you asked the average person who understood the concept of planets in our solar system, you know, do you think that there is life on other planets in our solar system? Their answer would almost certainly have been yes.
5:50Camden Miller:This is Lindsay Hayes. She's a NASA astrobiologist. And she explains just for a lot of scientific history, people really just assume there was advanced life on Mars.
6:02Katie Stack Morgan:The science community was looking at Mars, not asking the question, are there Martians? But what are the Martians like? And what do they do? And how are they living on their planet?
6:13Camden Miller:And it wasn't just a few fringe scientists. Really big thinkers were in on this idea.
6:17Katie Stack Morgan:Percival Lowell, H.G. Wells, Alexander Graham Bell were all folks who read about Mars and wrote about life on Mars and conditions on Mars.
6:27Camden Miller:In particular, the astronomer Percival Lowell, he hypothesized that an advanced civilization had built these canals on the surface of Mars. And these wild ideas just stuck around for a long while. Lindsay told me about a newspaper clipping from 1915.
6:43Katie Stack Morgan:After the outbreak of World War I, there was articles that were essentially like, the Martians can probably see we're at war. And they probably think, what are those human beings doing? Because they're probably so much more advanced. They probably don't have war.
6:58Camden Miller:The thing is, though, we couldn't really figure out whether there were Martians until we just got an up-close view of Mars. So starting in the 1960s, NASA sent a series of spacecraft to fly by and take a look.
7:11Morgan Cable:In 1965, the unmanned spacecraft Mariner 4 flew past Mars 6 ,000 miles above its surface. Its single camera took photographs that were startling.
7:23Katie Stack Morgan:We realized not only do the canals not exist, but Mars is a lot less hospitable than we thought it was.
7:34Camden Miller:Mars is a desert. It's rough and pockmarked with craters. It's desolate, dead.
7:41Katie Stack Morgan:It certainly wasn't inhabited by the Martian pacifists. It's not only not inhabited by advanced life, it is pretty hard to imagine how life would really be continuing on the surface of Mars.
7:54Camden Miller:There were no obvious signs of life on Mars. But that didn't end the search.
8:00Katie Stack Morgan:Mars is a planet that continues to show us just enough to keep us intrigued. Mars is still the most similar surface environment of any planet or of any body in the solar system. There's still an atmosphere there. You know, it still gets a good amount of sunlight. It's still intriguing in the potential.
8:22Camden Miller:In the decades since the Mariner missions, we've sent landers to Mars and orbiters and rovers to land on the planet. And we've collected a lot of information. We've realized that those scientists from 100 years ago, they were just asking the wrong question. The question isn't who are the Martians. It might be when were the Martians? The quest to find signs of ancient life on Mars is to ask some of the biggest questions possible about life and how it began and how it begins. It could help us understand life on our own planet, where it came from, and perhaps even weirder, show us that it didn't even start on Earth at all.
9:05Camden Miller:So that's what we're going to talk about on this week's show. Was there ever life on Mars? And how would we know if we found it?
9:21Katie Stack Morgan:You're looking at a kind of world that hasn't existed for millions of years. It hasn't existed for millions and millions and millions. It's almost as if time forgot this place.
9:31Morgan Cable:Is there life on Mars? There's a whole universe out there, Steve, beyond anyone's comprehension.
9:39Camden Miller:Since the 1960s, scientists have found evidence of a lost Mars. This was a Mars billions of years ago where there were rivers, lakes.
9:50Katie Stack Morgan:Mars is a very different place today than it was four billion years ago, but you can see evidence of what it was like four billion years ago. What you see are things like what looks like the remnants of a huge river delta, which indicates not only did you have water flowing, but you probably had lots of water flowing over a long period of time that continued to deposit sediments.
10:11Camden Miller:A lot of the evidence of this lost Mars comes from on-the-ground work by rovers like the Curiosity, which has been driving on Mars since 2012.
10:19Katie Stack Morgan:There's a sort of standing joke, oh, scientists have discovered water on Mars again. You know, NASA has discovered water on Mars again.
10:26Camden Miller:Water is essential for all life as we know it. So that water could have had life, even if it was just microbes. And that life could have settled into the sediment of some Martian river delta. And then that sediment could have turned to rock, preserving that evidence that life existed. And those rocks could just be up there, waiting for us to find them. But it's not guaranteed.
10:50Katie Stack Morgan:Not only did life have to exist for long enough to sort of spread and take a hold and be something that was enough happening to be a process, but it also had to be preserved. And then it had to be preserved in a place that we can find. And so there's a certain, you know, needle in a haystack aspect to this as well.
11:10Camden Miller:It's a real long shot. But the best way to figure out if there is some life preserved in those rocks is to get those rocks here on Earth. And so in July 2020, NASA launched Perseverance, its latest rover to explore the Martian surface. Launch sequence to start. What's really cool here is that Perseverance is the first rover that's specifically collecting samples to be studied here on Earth. It's kind of like getting moon rocks back for the first time. These samples will be game changers. Possibly our best shot at answering the question, was there life on Mars? The skies look great. There is little wind.
11:53Camden Miller:The destination? Jezero Crater. This is a place where, billions of years ago, a river emptied out into a lake. It dropped sediments, rocks, and potentially life. And this is the exact sort of place where signs of life could have been preserved. Status check. Go Atlas. Go Centaur. Go Mars 2020. But first, Perseverance had to survive a really dangerous journey.
12:19Morgan Cable:5, 4, engine ignition, 2, 1, 0, and liftoff.
12:26Camden Miller:It wasn't the seven-month flight through space that was so dangerous, but actually landing on Mars.
12:32Morgan Cable:They have confirmation of entry interface. Perseverance is currently going 5.3 kilometers per second at an altitude of about 120 kilometers from the surface of Mars.
12:44Camden Miller:The landing was called the Seven Minutes of Terror. It took about seven minutes for the spacecraft carrying the rover to go from the top of the Martian atmosphere to landing safely at the bottom. And all the while, it had to slow down from around 12 ,000 miles per hour to, well, you know, zero.
13:02Morgan Cable:Our current velocity is about 5.36 kilometers per second and an altitude of about 67 kilometers from the surface.
Read the full transcript
13:11Camden Miller:A lot could have gone wrong. Mars is so far away that any command NASA sent to the spacecraft took several minutes to get there, which meant they just couldn't pilot the spacecraft in real time. It had to land itself in a very rough landscape.
13:27Morgan Cable:She was deployed.
13:28Camden Miller:The navigation has confirmed that the parachute has deployed and we're seeing significant deceleration. But the spacecraft was just too heavy to land by parachutes alone, so NASA needed to use a special maneuver called a sky crane to get the rover down to the surface. Sky crane maneuver has started about 20 meters off the surface. When the spacecraft was just above the surface, it fired thrusters so it was hovering, and then that really heavy 2 ,000-plus-pound rover was lowered down from the spacecraft by cables. Once it was on the ground, the spacecraft detached the cables from the rover and then blasted away so it wouldn't fall on top of it.
14:08Morgan Cable:Touchdown confirmed. Perseverance safely on the surface of Mars, ready to begin seeking the sands of past life.
14:21Camden Miller:Perseverance has been on the surface of Mars for more than a year now, looking for that perfect rock that might contain evidence of past life. But how do you choose those rocks on a planet full of rocks? How do you find that needle in that enormous haystack? We wanted a firsthand perspective here, so we did something fun. We sent producer Mandy Nguyen to Mars.
14:47Lindsay Hays:Well, I didn't technically get to Mars, but I went to the next best place.
14:53Katie Stack Morgan:So what we're looking at is what essentially looks like a large sandbox with rocks of different sizes.
15:00Lindsay Hays:I went to the Mars Yard at NASA's Jet Propulsion Laboratory in Pasadena, California. And this is where I met Morgan Cable, a research scientist on the Perseverance team.
15:10Katie Stack Morgan:We can position these large rocks and boulders as obstacles to be able to test the autonomous navigation of the Perseverance rover.
15:20Lindsay Hays:So this is almost, sometimes it functions as an obstacle course? That's exactly right. The Mars Yard is the best place to test the rover without going to space. It's supposed to be like the Martian landscape itself. Dusty, rocky, and full of boulders.
15:36Katie Stack Morgan:Well, you wouldn't see the trees in the background or hear the birds chirping. But yes, this is essentially what you would see. And maybe in the evening, close to dusk or at night, you might look up and see a little blue dot in the sky and realize that that's where everyone else who's ever lived in human history has been. It's right there in that tiny little blue dot. And you can... And maybe there wouldn't be construction on Mars. Yeah, I know. There is some construction going on here. Let's walk back inside. Okay.
16:11Lindsay Hays:Morgan led me into a small warehouse in the Mars yard, which is where the rovers are. But these aren't the actual rovers that end up on Mars. They're exact replicates.
16:20Katie Stack Morgan:So we have a copy of the Mars Perseverance rover right here, and that allows us to run all sorts of tests, diagnostics, to do some experiments here that might be perceived as a little bit too risky to try on Mars because we can very easily make repairs here, and we can't really do that quite as easily on the red planet, at least not yet.
16:39Lindsay Hays:Can we go look at the rover?
16:42Katie Stack Morgan:We can totally go look at the rover. Amazing.
16:45Lindsay Hays:Look at the rover. Perseverance was kept behind these red velvet ropes, kind of like what you'd see at museums. But we weren't allowed to go closer than about six feet because the static electricity humans generate could tamper with the instruments on the rover. Okay, can you describe to me what we're looking at? Like, it's... This is really big. They are really big, right? Perseverance kind of looks like a huge WALL-E. It's car-sized, 7-foot tall, 2 ,200 pounds, nuclear-powered, with an extendable arm and a drill attached to it. It also just looks so rugged, like the six wheels. I mean, I guess this is the sort of thing ready to just exist on Mars and drive around.
17:27Katie Stack Morgan:All of the instruments work together to be able to give us a more complete picture of Mars' geology and its potential for astrobiology, which is what excites me the most.
17:38Lindsay Hays:The actual Perseverance rover, not the copy, is all the way on Mars now. But it can't get around all on its own. That's where Camden Miller comes in.
17:48Morgan Cable:I am a rover planner, a.k.a. rover driver.
17:52Lindsay Hays:Even though Perseverance can navigate to a specific spot on its own, it still needs constant guidance from scientists and engineers like Camden to determine exactly where it should go.
18:03Morgan Cable:Every Martian morning, we'll point its antennas at Earth and listen for commands and receive the commands, and then once it receives them, it'll start executing them.
18:11Lindsay Hays:But figuring out when that Martian morning starts can lead to some issues.
18:17Morgan Cable:When we landed, we were living on Mars time for about two months.
18:21Lindsay Hays:One Martian day is about 40 minutes longer than an Earth day. So keeping up with Martian time is like shifting two time zones every three days.
18:29Morgan Cable:So yeah, the schedule gets a little crazy when you're living on Mars time. One time, me and my two roommates, we were all sitting at the dinner table, and I tend to wake up earlier. I was even waking up early on Mars time. And so I was eating lunch. My other roommate who was on Mars time was eating breakfast. and our other roommate who wasn't on Mars time was eating dinner. We were all sitting at the table eating different meals at the same time.
18:51Lindsay Hays:All of these scheduling workarounds can sometimes make driving the Mars rover seem like a chore.
18:57Morgan Cable:I think I was on shift one time and we were looking at these pictures of the ground in front of the rover and it was just nothing but pebbles. We're like, this is a really boring workspace. It's just nothing but pebbles. Then it dawned on us, we're looking at rocks on another planet. We're calling it boring. What's wrong with us? Holy crap, we're driving a rover on Mars. So Camden's controlling the rover, but when he wants to know exactly where to look for
19:20Lindsay Hays:signs of life on Mars, he has to talk to scientists like Morgan.
19:24Katie Stack Morgan:We're exploring different sedimentary layers, and we're looking at changes in composition as we go through those, just like a geologist would here on Earth.
19:33Lindsay Hays:Morgan specifically works on an instrument called PIXL, one of the attachments of Perseverance's robotic arm that analyzes the makeup of Martian rocks.
19:41Katie Stack Morgan:A pixel is basically a very fancy x-ray that fires at rocks, and when those x-rays interact with the actual atoms in the rock, they fluoresce. And in doing that, we can actually give you a map of what kinds of elements are in that rock.
20:01Lindsay Hays:The only way we'll know for sure if any of this is life, or at least points to life, is if we're able to look at rock samples up close and back on Earth. with all the equipment scientists couldn't pack onto the rover. We have to bring the rocks home, because sometimes what seems like life at first might not be life at all.
20:20Katie Stack Morgan:You might have heard of a particular Mars meteorite that was collected here on Earth in Antarctica back in 1984. It was called ALH 84001.
20:31Lindsay Hays:Basically, a chunk of Mars was ejected into space by some sort of impact, floated around for a while, and eventually crash-landed onto Earth.
20:40Katie Stack Morgan:We were able to cut that meteorite open, look inside, and we saw some structures that looked an awful lot like cells, tiny little worms. But they were much, much smaller than the width of a human hair. Very, very tiny. And just by your eye, you would say, oh, that looks like a worm.
20:59Lindsay Hays:That looks like life. That must be life. Scientists thought that they had actually discovered tiny Martian life inside this meteorite. But now many scientists think that what looked like fossilized bacteria was actually shaped by geochemical interactions between water and rock.
21:14Katie Stack Morgan:That's why whenever we search for life or evidence of life in other places, we don't just rely on one thing. We don't just rely on an image that might trick our eyes. We don't just rely on one chemical technique that could potentially be confounded by something that we don't fully understand.
21:32Lindsay Hays:It's also possible that we might actually find life in these rocks and not recognize it. It just might be too different from life on Earth for us to identify. But for us to have the best possible shot, we need to get the rocks back to Earth.
21:45Katie Stack Morgan:All of those bits of information need to be collected together and analyzed as a whole for us to really be confident that we have made what I think would be civilization-level science of finding out for the first time in human history that we're not alone.
22:03Lindsay Hays:Perseverance can't get the rocks home on its own, so NASA and the European Space Agency have plans to retrieve the samples with a different spacecraft sometime after 2030, which would be the first time we've ever taken Mars rocks all the way back to Earth.
22:22Camden Miller:This whole journey that Perseverance is on, what if it all works? What would it mean to find evidence of life on Mars? That's next.
23:01Morgan Cable:$15 a month, even unlimited. That's it. Happy ending. Zero tears. Give it a try at mintmobile.com slash switch. Upfront payment of$45 for three months,$90 for six months, or$180 for 12-month plan required. $15 per month equivalent. Taxes and fees extra. Initial plan term only. Greater than 50 gigabytes. May slow when network is busy. See terms. This episode is brought to you by Accenture. When your advertising operations fall out of sync, everything else follows. Spotify and Accenture are working together to reinvent the rhythm of ad sales. using automation, analytics, and smarter workflows to simplify campaign delivery and access better data across the business.
23:35Morgan Cable:The result? Less time spent on operations, more time connecting brands with the moments and fandoms that matter most. Learn more at Accenture.com slash Spotify. This episode is brought to you by Google Chrome. You think you know a browser, but Gemini and Chrome, that's new. It can help you with practically anything on the web,
23:54Camden Miller:like restoring a vintage motorcycle from a 50-page restoration block, or finally break down that long article you've had open for weeks. Gemini and Chrome is here for it. Ready to make anything online make sense? There's no place like Chrome. Check responses set up required, compatibility and availability varies 18+.
24:19Camden Miller:Unexplainable, we're back. Hey, Mandy. Hi. So you went on this really fun field trip, and I'm just jealous. You saw this Perseverance clone up close.
24:30Lindsay Hays:Yes, I did. And it was so incredible.
24:33Camden Miller:What do you think will happen if all of this works and we get these rocks back?
24:38Lindsay Hays:I mean, I think that's going to be such a huge deal. We've never deliberately gotten rocks back from Mars. And if they could tell us anything about if there was life there, I think that'd be like, as Morgan said, civilization defining science if we were to find anything.
24:55Camden Miller:What do you hope? Do you hope there was life?
24:57Lindsay Hays:I mean, of course. I think that'd be so exciting. That's like the big question, right? That like years and years and decades that people have been trying to figure out.
25:06Camden Miller:And it's more than just the answer to, is there life on Mars? Lindsay Hayes, the astrobiologist at NASA I was talking to, she was telling me about like getting a sample of life on Mars could really teach us about where life on Earth comes from or just like where life comes from in general?
25:26Katie Stack Morgan:You know, to me, the reason that I am interested in the search for life, it has to do with this concept of how interrelated life is on Earth, right? All of life that we know of on Earth is all related.
25:41Camden Miller:You and I are related to each other. You know, if you go back on our family trees far enough, however many thousands of years, we'll find an ancestor in common. And that's true of not just humans, but at some point, there's a common ancestor between a human and a chimpanzee, going further back. And even further back, there's a common ancestor between a chimpanzee and a fish. And then going back, there's a common ancestor between a fish and bacteria. And Lindsay has this really epic question.
26:14Katie Stack Morgan:Knowing that all life on this planet seems to be all related to each other, what would life on a different planet be like?
26:22Camden Miller:If we found an example or a specimen that showed there used to be life on Mars, her big question is, well, is that life related to life on Earth? Does the life on Mars share a common ancestor?
26:38Katie Stack Morgan:At which point, wow, that means that, you know, maybe life is created in one place and then sort of spreads between planets or moons.
26:46Camden Miller:It could be we're related to Martians, which is, whoa, how are we related to Martians? If that's the case, maybe life didn't start on Earth at all. Maybe it started on Mars and then somehow, like, got here. She used the term, like, planet swapping spit. Like, as the planets are forming, maybe, you know, a bit of an asteroid blasts off a chunk of one that has some life on it that goes into another planet. But I mean, weirder scenarios can come from there. Like what if life didn't start on Mars or Earth, but somewhere else?
27:14Katie Stack Morgan:Ooh, spooky.
27:15Camden Miller:Spooky. Like where did that life come from? But then like every answer to this question is epic because if it turns out the life on Mars is somehow different or like too different to have a common ancestor with life on Earth, then maybe that means like life spontaneously started there.
27:33Katie Stack Morgan:Which means that life is so fundamental a process of the universe that you can have two different life-generating events in the same solar system. And that totally changes our perception of life. But also, is it like us or is it something completely different? Is life a fundamental process that happens any time there is a habitable environment?
27:58Camden Miller:And in that case, it might mean that anytime the conditions are right for life anywhere in the galaxy around any planet, like, life will just form because that's what it does. So that is just such a woe for me that, you know, if we do get samples back and, you know, as you were describing, there are, you know, a lot of converging lines of evidence and we kind of reconstruct a picture of whatever this ancient, probably microbial life was. we really get really close to the question of all questions of how does life start?
28:35Lindsay Hays:So if we were to find life in these little rocks, we'd either be related to Martians potentially, or it could just be the beginning of finding a lot more life everywhere.
28:46Camden Miller:And this is also a cool thing about the overall missions on Mars is that the surface of Mars is really old. It's like billions of years old. And so anything we find there is going to be just so old and so ancient and just like older than anything we can find on Earth. So we might even find like an earlier form of life than has ever been discovered on Earth, like something even more primordial. Wow.
29:19Camden Miller:I don't know. Yeah, it's really kind of like, I love this contrast of like, a lot of these answers can be figured out from just like a handful of rocks. Isn't that wild to you?
29:31Lindsay Hays:Yeah, that's super, super wild to me. I mean, now we just have to play this waiting game. We're not going to know till probably like 10 years or so.
29:42Camden Miller:Why so long?
29:43Lindsay Hays:I mean, so the sample return missions still have to be planned. Someone needs to send a rocket to collect those rocks and bring them back. Right now, the rover's just carrying all of them. But eventually, they'll have to decide where to place these samples on the surface of Mars so that they can be picked up later. There's no definitive, I think, timeline on that yet.
30:08Camden Miller:Yeah, that's kind of funny. It's like interplanetary FedEx needs to come and pick them up.
30:13Lindsay Hays:That's basically how it's going to be. But I keep, you know, like there's so much work involved into this project. I keep wondering, what if we bring all these rocks back? We spend all this time doing all this work and scientists look at it and they don't find anything.
30:32Camden Miller:You know, it's funny. That's the question I asked Lindsay. And she just told me that, well, she just would want to look somewhere else on Mars.
30:39Katie Stack Morgan:you know, there's the question of like, you know, it took me a hundred tries to make the light bulb and it's not that I failed a hundred times, but I found a hundred ways not to make a light bulb. You know, it's a similar kind of thing, right? And so, you know, let's keep looking. Let's see what else we can find.
30:54Camden Miller:I think I really get Lindsay's persistence here. It's like every answer to the question, was there life on Mars? It's just so perspective shifting. It's so close to that big question of why are we here? Which is why she would want to go back again and again and just try to find the evidence of life. And maybe there won't be, but it seems worth it to look.
31:21Katie Stack Morgan:The search for life is never going to be an easy thing. But the questions that you learn, even if you don't answer, was there life here? The answers you find can tell you a lot more about planets and about the solar system and about life.
31:38Camden Miller:It's just so cool to imagine that on this rusty colored world amid dust and billion-year-old rocks, there is this lonely robot on this mission, you know, kind of completing a dream that scientists have been thinking about for hundreds of years.
31:58Lindsay Hays:Well, I mean, it's also not so lonely. When I think about perseverance on Mars, I think it's really easy to think about it as a lone rover traversing the desert landscape, the rocky red, you know, ground. but after going to NASA and speaking to the scientists I can't help but think about all the people and all the history that is behind this rover and how like yes it's kind of in a way alone on Mars but it's not truly alone. One of the things that Morgan said to me was that with the perseverance it's almost like we're extending our senses to the red planet and so So to me, this rover is a part of us, but across space, you know?
32:49Camden Miller:I love that.
32:58Camden Miller:This episode was reported and produced by Mandy Nguyen and Brian Resnick, with production help from Meredith Hodinot and Bird Pinkerton. It was edited by Catherine Wells, with additional edits from Meredith and me. I also scored the episode, mixing and sound design from Christian Ayala, and fact-checking from Richard Sima. To read more about some of the topics we cover on the show, or to find episode transcripts, check out our site at vox.com slash unexplainable. If you have thoughts about the show, you can always email us at unexplainable at vox.com, or you could leave us a review or a rating, which we'd love too.
33:40Thank you.
From the publisher
NASA found a Martian rock that might have traces of ancient life. It's perhaps the most tantalizing revelation in the century-long search for Martian life. (Updated from 2022)
Guests: Katie Stack Morgan, project scientist for the Perseverance rover; Lindsay Hays, astrobiologist at NASA; Morgan Cable, research scientist for Perseverance; and Camden Miller, rover driver for Perseverance
For show transcripts, go to vox.com/unxtranscriptsFor more, go to vox.com/unexplainableAnd please email us! unexplainable@vox.comWe read every email.Support Unexplainable (and get ad-free episodes) by becoming a Vox Member today: vox.com/membersThank you!
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