Planetary Radio: Space Exploration, Astronomy and Science - Earth Microbes! Welcome to Mars

Episode Date: February 7, 2017

University of Arkansas grad student Rebecca Mickol and her team have demonstrated that some Earth bacteria can survive in the extremely thin atmosphere of Mars. Could Martian bacteria thrive under the same conditions?Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Hey, podcast listeners, got a special programming note for you. On the evening of Thursday, February 16th, we're going to do another Planetary Radio Live. It's been a while. We're going back to KPCC, Southern California Public Radio, to talk about NEOs, Near Earth Objects. And we're going to have a fantastic time with a great panel, Paul Chodas, who runs the NASA Center for Neo Studies at JPL. Paul's colleague, Amy Meinzer, senior research scientist there, head of the NeoWISE mission. Lindley Johnson is going to join us from NASA headquarters. He's the NASA planetary defense officer.

And a guy named Bruce Betts will also be on stage. If you can't join us in person at KPCC, and I think, at least as I speak, there are a few free tickets left for this Thursday, February 16th, 7.30 p.m. show. Anyway, if you can't join us in person, there will be a live webcast. Now, I'll turn it into a Planetary Radio episode very soon after, maybe the following week. But if you want to see us on stage, you can tune in. You can watch the live stream. Easiest way to get there is go to scpr.org and just look for events. And we'll be listed right there.

All right. Hope you can join us one way or another. It's going to be a lot of fun as we talk about Armageddon. Thanks for listening. Here's this week's show. Microbes of Earth, welcome to Mars, this week on Planetary Radio. And welcome to you. I'm Matt Kaplan of the Planetary Society with more of the human adventure across our solar system and beyond. Rebecca Michael has learned that at least a few examples of our planet's smallest living creatures can survive the terribly low atmospheric pressure of the red planet.

She'll tell us about her fascinating experiment. Charles Bolden is no longer NASA's administrator, but he doesn't appear to have lost his interest in the agency's future. That's what we'll talk to Bill Nye about. We'll take the What's Up segment to Bruce Bett's live astronomy classroom. Planetary Society digital editor Jason Davis gets us off to a great start. Jason, welcome back to the show. I am very grateful to you for being the first of the very worthy people we'll have filling in for Emily while she's on her sabbatical. And I suspect we'll be talking to many times over this three-month period while she's working on her book.

So, like I said, welcome back. Thanks, Matt. Thanks for having me. And it's always happy to fill in. We are going to talk about this piece, which actually already came up on the show. I think I talked with Bill Nye about it a couple of weeks ago. You posted it to Planetary.org on January 26th. It's a great piece.

The moon versus Mars as a target for humans. Why would we go back to the moon? Yeah, so that's a great question. And it's kind of been this rumor that's been circulating in a lot of policy circles. It pops up in the media every now and then. And now it's kind of reaching this fever pitch into which are we going to do? Are we going to go to the moon or Mars? And the arguments for the moon that are being put forward are, number one, it's closer and easier to get to. So you could see a quicker payoff on your investment if the Trump administration were to direct humans to land on the surface. And number two, there's a lot of arguments being made for this kind of private

public partnership situation where you might be able to enable some commercial companies to provide services, kind of the way that NASA has done that with SpaceX and Orbital ATK and Low Earth Orbit for the International Space Station. Now, in the article, I spoke to a lot of folks about this possibility, and there was some skepticism, kind of split on whether or not that same business model for low Earth orbit could work at the moon. But right now, that seems to be kind of the leading two arguments for going back. I know it's talked about as a stepping stone to Mars, but are there science reasons for going

back to our satellite? Yeah, NASA's decadal survey that's released every 10 years to kind of define priorities for planetary science, it does mention that there are some important questions to be gained about the moon, about the moon's internal composition. And in fact, NASA would like to send a sample return mission to the South Pole. That's one of the candidates for the next New Frontiers class mission. But when you talk about Mars, you're really talking about these questions of life. And that's the whole reason NASA's Mars Exploration Program exists, is to go to Mars and determine whether there used to be life there, or whether there maybe still is life there. And so there are good science questions on either the moon or Mars, but you're not going to find life on the moon.

So, you know, it is a very different science question. Well, there is much more to this piece, this very well-researched piece, by my colleague Jason Davis. As I said, it's a January 26 post at planetary.org, and we'll put up a link on this week's show page as well. Jason, thanks very much for the preview. And I'm sure we'll talk to you again soon. Thanks, Matt. Looking forward to it. Jason Davis, he's the digital editor for the Planetary Society. Up now, our mutual boss, the CEO, Bill Nye, the science guy. Bill, welcome back to the show. You were just telling me that you were reading something that the now former administrator of NASA has to say.

Charlie Bolden, Vietnam War fighter pilot, veteran, shuttle pilot, and former administrator of NASA, is concerned about Earth science at NASA. He's not expressing concern about the space launch system, big rocket, not really about planetary science, not really about heliophysics, just about Earth science. And his concern is that there are people in U.S. Congress who want to move Earth science out of NASA and put it into, nominally, the National Oceanic and Atmospheric Administration, from NASA to NOAA. But his concern is NOAA doesn't make satellites, they analyze data once the data are beamed down to Earth. And everybody's concern in that little world is that it'll effectively kill Earth science. Once you take it out of NASA, it'll just disappear. The satellites won't get built. They won't be monitored. They won't be maintained and so on. everybody would agree is because there are certain people who don't want to find out anything more about climate change. There are people that just, if you don't know about it, if you don't think

about it, it won't be happening. It's a form of denial. And it's very much human nature, I understand, that when you have this conflict between what you believe and what you see or the evidence before you, you've got to resolve this conflict. And this is an old psychology thing called cognitive dissonance, where you have dissonance about what you're thinking. And so you resolve this dissonance by just presuming that there's a conspiracy or that it's not really happening. Dr. Bolden was just being objective. Hey, I'm worried about earth science at NASA. So anyway, the other thing that I'm very troubled about, Matt, is there's concern that the Mars 2020 rover will slip into the future. They'll have to rename it the Mars 2023 rover or something.

And that would be sad. We want to continue the search for life on Mars. And we want the robotic exploration program to move along no matter what happens in human spaceflight. And, you know, now one of the remarkable things about the new administration and the people that are being brought in to run NASA is there are old school people that really want to send humans to Mars. I think that would be great. You know, we could do it as soon as 2028, 2033, depending on the orbit. But let's not forget that we got to keep robotic exploration going to make sure we have a good place to land and all these important details of actually going to Mars. So it's another just amazing time, Matt, where all sorts of things are

happening in politics that affect space. And we'll continue to follow those things, Bill. Thank you very much. Thank you. Let's change the world, Matt. That's the CEO of the Planetary Society, Bill Nye. We're going to go back to Mars, or at least a simulation of Mars, and learn if there are some Earth microbes that might just be able to survive under the surface of Mars. There was good news last September for those of us who hope to find life elsewhere in the universe. It came from a lab at the University of Arkansas, Fayetteville. The paper was titled

Low Pressure Tolerance by Methanogens in an Aqueous Environment, Implications for Subsurface Life on Mars. Its lead author is a graduate student named Rebecca Michael. Rebecca is in the school's space and planetary science program. With bachelor's degrees in both astrophysics and evolutionary biology, She has interned at both the Goddard Space Flight Center and Kennedy Space Center, but she was at home in Arkansas when I got her on Skype a few days ago. Rebecca, thank you for joining us on Planetary Radio, and congratulations on the publication of this paper in Origins of Life and Evolution of Biospheres. Seems like a very appropriate publication for what you, your findings. Yes. Seems like a very appropriate publication for your findings.

Yes, thank you, and thank you for having me. This work is a real milepost, I think, in our search for life elsewhere in our solar system and perhaps beyond. And I was going to ask you, why didn't anybody think to do this before? But I guess they kind of did. Can you explain? Yeah, so I focused on low pressure. Honestly, most studies of extreme life out in space or on another planet look at temperature and UV radiation, because those are the most damaging effects.

And there's tons of publications on that. But on Mars specifically, the pressure is 1 100100th that of the atmospheric pressure of Earth. At best, right? Yeah. And not many people have looked at it. Dr. Andrew Scherger, he found that there might be actually a 25 millibar limit to life that can survive. We wanted to explore this as well because we work with methanogens in our lab. They are microorganisms that produce methane. Methane has been discovered on Mars, and maybe methanogens

could have contributed to that methane. And just to be clear, we have a sophisticated audience, but for those who aren't aware of them, methanogens, particular kind of fairly primitive life? Yep, some of the first life here on Earth. And they're anaerobic. They don't like oxygen. Yes, they are strict anaerobes. So even the smallest bit of oxygen is lethal. So that's one thing that they might like about Mars. Yes, yep. Except there is a little bit of oxygen in the Martian atmosphere, but that's another, that's another. Tell us about what you actually accomplished in the lab with this device that you guys call Pegasus. So we have a Pegasus planetary simulation chamber. Pegasus is just the name that we gave to it.

It's a cylindrical stainless steel chamber and it's a vacuum chamber. And so we're able to reduce the pressure down to whatever we want, six millibar, which is about the average on Mars. One of our issues though is our methanogens we incubate in a liquid medium and at low pressure, this liquid evaporates. And so that's our main issue with these experiments that we ran. But that was also the novel idea, is we used a liquid medium versus just drying the methanogens out. How did you keep this liquid from immediately boiling away as it normally would in that kind of pressure? Ultimately, we didn't keep it from boiling away very well, and that limited the length of our experiments. One thing we do, we had the methanogens in test tubes, obviously, and we

would puncture the test tubes with a needle so that we could slow the rate of evaporation. so that we could slow the rate of evaporation. We also utilized a Martian regolith simulant, so a dirt example, I guess. We put that on a cotton ball above the liquid so it wasn't touching, but that also slowed the diffusion of water out of the test tubes. I love that, to see that,

because you actually did sort of several runs of this experiment. And one of them, you bought some of that Martian regolith stimulant from Johnson Space Center? Yep, I think so, yes. Pretty cool. I mean, I've touched that stuff and lunar regolith, and it's just fun to think that, okay, I may never really touch the real thing, but this is the next best thing. Yes. So you still had some problem with this, the solution evaporating away, but you got some pretty interesting results. And were they unexpected? Honestly, since no one had done this really before with methanogen, seeing if they could survive in active growth. Yeah,

we didn't know what would happen. And we thought they'd survive, and they did. Basically, they're just subject to desiccation as the liquid water evaporates. But in one of the final experiments in this paper, we created microenvironments in the test tubes where we punctured the test tubes, brought the test tubes to a lower pressure, I think about 50 millibar, which is about 10 times higher than that of Mars. But then we removed the needles to keep the test tubes at 50 millibar. And then for the duration of that experiment, it was 21 days. The methanogens were at 50 millibar in a liquid medium. I'm not sure if in this paper, but in some recent experiments I've done, one of our organisms is actively producing methane at 50 millibar. What really makes this exciting is the findings of methane on Mars, right? Which have been kind of iffy, but it seems like something's going on, whether it's biological or not.

Yes, there are a lot of controversial findings, but there's space-based findings, there's ground-based findings, and there's even findings from the Curiosity rover. There are a lot of arguments for and against it, and there also are a lot of arguments for where is that methane coming from. It could be serpentinization on Mars. Which is just mineralogical stuff. Water-rock reactions. It could be comet impacts, asteroid impacts, even volcanoes.

There's a lot of different options. But of course, we like to think methanogens. And on Earth, almost 90% of methane on Earth is biological in origin. That's grad student Rebecca Michael at the University of Arkansas. I'll be back with her in a minute. This is Planetary Radio. Where did we come from? Are we alone in the cosmos?

These are the questions at the core of our existence. And the secrets of the universe are out there, waiting to be discovered. But to find them, we have to go into space. We have to explore. This endeavor unites us. Space exploration truly brings out the best in us. Encouraging people from all walks of life to work together to achieve a common goal. To know the cosmos and our place within it. This is why the Planetary Society exists. Our mission is to give you the power to advance space science and exploration.

With your support, we sponsor innovative space technologies, inspire curious minds, and advocate for our future in space. We are the Planetary Society. Join us. Welcome back to Planetary Radio. I'm Matt Kaplan. Rebecca Michael and colleagues at the University of Arkansas Fayetteville have shown that certain Earth bacteria can survive in the Martian atmosphere, where the pressure is barely 1% of what we live in at sea level on this planet. The implications for the possibility of past or even current life on, or a few feet under, the surface of Mars are obvious. You obviously had to deal with organisms that evolved here on our planet,

where you even point out in the paper, even on the top of Mount Everest, you're only looking at about a third the atmospheric pressure that we have at sea level. But you did mention an example of where microbes have been found at a somewhat equivalent pressure. Yes. So in the atmosphere, there's organisms at various levels in the atmosphere and about, I think, 20 kilometers up, that's about 6 to 10 millibar, and that's the pressure of Mars. And we have discovered organisms there. On Earth, it's probably not a stable ecosystem at 20 kilometers in the atmosphere. There's nothing else there. But obviously these organisms can get there, survive for however long, and then come back down to Earth.

But right now that's our closest ecosystem. Which, of course, tells us nothing about how microbes might have evolved on Mars, where they maybe had billions of years to adapt to these conditions. Exactly. And on Mars, too, the way we get away from the UV radiation at the surface is methanogens are non-photosynthetic, just a few millimeters of Martian regolith, and they'll be protected from radiation. Does that hint at where you may be taking the research next? Yes. In our lab, we emphasize that we think the methanogens are subsurface. Even if they're just a little below the surface,

they would still be subjected to the low atmospheric pressure. If they're a lot deeper, the pressure might be higher. But a lot of our research also deals with methanogens being able to utilize nutrients on Mars for growth. A separate project I'm working on with a postdoc at NASA, we're looking at the methanogens ability to grow on montmorillonite and nontronite and some other clays that are found on Mars. And we found that certain methanogens can utilize these nutrients as well as hydrogen and carbon dioxide to produce. Wow. We're not too far off from the next rover going to Mars. This one is going to go specifically to look for life, or at least signs of past life, perhaps better informed now because of work by people like you.

Would you be shocked if it were to discover methanogens a few millimeters down under the surface of Mars? I wouldn't be shocked. I think that would be absolutely amazing. It would. It would take a lot of convincing, though. I think there'd be a lot of skepticism, obviously, even on my part. As there should be. Yeah, but I think there's life there. Life evolved on Earth so early on. Mars had a similar origin. I think life had been there. Maybe it's still there. Maybe it's underground. I think there's some microorganisms we're not seeing yet.

All right. From your mouth to the gods of Mars, I hope. There's one other point that I don't want to miss. You did draw a distinction in your work between survival, mere survival, and going beyond that. Talk about that. Yes. In this paper, I want to be clear, we were just looking at survival. So for the methanogens to actively grow, they would need to produce methane. You know, the cells would need to multiply. We did not test that in these experiments. Measuring methane production under low pressure is difficult, and we have not achieved that yet. And so that is why these are mainly survival experiments, except with the last experiment in this paper, the microenvironments, that's where we're trying to show active methane

production, and we're almost there. You're a grad student. Yes. But you're the lead author of this paper. Yes. That happens now and then. We get to talk to folks like you on this show. It makes me think that you have an enlightened mentor standing behind you. He'd like me to say that. Tell us about your boss, Timothy Kroll. Tim Kroll, he is a great advisor, honestly. I visited before I came here for grad school in 2011, and we hit it off. We have the same kind of humor. We really get along well. I owe my success to him, honestly. He's supportive, but he also, he's hands-off. This is my PhD. He'll guide me when I need guidance.

He'll help me when I need help. But it's my choice. I come to him with experiments. His idea was to, initially, the low pressure. But I have a very, my dissertation will be very wide ranging with all the experiments I've done. He's a great mentor. He really is. How far are you from putting those extra letters behind your name, if all goes well? Four months.

Wow. Okay. I should let you get back to writing that dissertation. Just one other person I want to ask you about, because he's just one of my favorite people that I've met through this show and elsewhere. And that's Chris McKay. You gave him a special credit in the paper. Why? He actually was one of the reviewers. And he had some very nice suggestions for making the paper better. He and Dr. Kroll have collaborated a lot on previous studies. I just know him as a reviewer, and I

thanked him for his helpful comments. He's a good guy. I'm not a bit surprised. Okay, I got to ask you about one more thing because I found it in your bio. What is Space Hogs? So Space Hogs, that is one of our outreach groups on campus. And SPACE is actually an acronym. It stands for Space and Planetary Association for Collaboration and Education. Well done. So we just call it SpaceHogs. It was developed, I think, 2011, 2012. And our idea is to spread science awareness on campus and to the public.

One of our most successful events was the 2012 Transit of Venus. We were like, this is important. We should get out there. And it was bigger than we could ever imagine. We had news crews. We had local astronomers, amateur astronomers astronomers and a ton of public we had it out on one of the campus agricultural fields

and people got to see Venus transiting the sun and that was awesome and we work at elementary schools and middle schools and high schools too Great work We'll put up a link to the Space Hogs page as we will to some of your work.

There's a very good Space.com article and also the abstract of the paper, which is available online. Rebecca, thank you. It has been a delight talking with you. And once again, congratulations on these great findings. Thank you very much. That's Rebecca Michael. She's a grad student at the University of Arkansas Fayetteville. And as you heard, she is doing pioneering work on showing whether life could exist or could have existed.

We'll stick with could exist on the red planet. We'll go on now to talk to a form of earthbound life known as Bruce Betts. of earthbound life, known as Bruce Betts. Time once again for What's Up on Planetary Radio. So I am joined by the Director of Science and Technology for the Planetary Society, Dr. Bruce Betts. And we are where? Tell us where we are, Bruce.

Well, Matt, we're at California State University, Dominguez Hills, and we are in my second class of my 14-class Introduction to Planetary Science and Astronomy class, and we're recording live in front of the cameras. Yeah, there are people out there watching us right now as we say this. And so if any of you have ever wondered what we look like when we're recording, then you could watch this. I don't recommend it. Apologies. Tell us, Bruce, what's up in the night sky? All right. We've got Jupiter and Spica dangling near it, rising in the around 10 p.m. So Jupiter looking super bright over in the east, high in the south in the pre-dawn. Speak of the bright bluish star a little bit to its lower right. And if you want a special Valentine's Day, February 14th activity,

go out and look for the moon near Jupiter, making for a lovely sight. Is that for me? No. No, it was not. In the early evening, you will see Venus dominating low in the west. Shortly after sunset, super bright looking Venus. And then to its upper left, kind of over to its left, much dimmer. Mars about 1 200th as bright as super bright Venus right now. We've also got Saturn in the pre-dawn east rising and getting higher over the weeks.

We move on to this week in space history. You love this one every year, Matt. 1971, Alan Shepard hits golf balls on the moon. That's right. He adapted one of the actual scientific devices, had a golf head stuck on it, a six iron, I believe, and hit at least two golf balls on the moon. Said it was an amazing drive.

You can't believe golfers, but he was working in one-sixth gravity. He was. You can actually go online and watch the shots, but they didn't have cameramen to follow it down the gray fairway. All right, we move on to random space fact. And to get the full effect of that, you really have to hear the radio show. But please, go on. If Earth were the size of a racquetball, then Uranus, or equivalently Neptune, would be about the size of a basketball. A little bit bigger than a basketball.

About four times the diameter of Earth are Uranus and Neptune. And which one would bounce higher on plywood? We'll have to try it. It's the only way to do it, see? For those watching at home, we've got racquetball, basketball, Earth, Uranus, or Neptune

that are very similar in size. Before we go on to the trivia contest, do you remember talking about the third stage of the Saturn V rockets that went to the moon, that took the Apollo astronauts to the moon? Yes. Alan Shepard. And that they hit the moon, they impacted the moon. Right. You said biggest thing ever to impact the moon, right?

Biggest human-made objects to ever impact the moon. Good qualifier. I guess human-made objects to ever impact the moon. Good qualifier. And you said you thought that they had used those impacts with seismic equipment. Oh, right, yes. We got a confirmation from our listener, Stephen Donaldson, in Hagerstown, Maryland. He said, indeed, that there was equipment left behind powered by a radioisotope thermal generator, one of those things that doesn't need solar cells.

He actually checked it out on YouTube, and I guess they talked about this. So you were dead on. Yay! Yay! Now, it seems like they would utilize that when they know something's going to hit, and they've got seismometers there, and indeed they did. So we move on to the trivia contest now.

You ready? Please. We asked you what solar system moon is closest in size to Mercury, closest in diameter to Mercury. What solar system moon? How did we do, Matt? We had a huge response. I only saw one person who got it wrong, which is too bad because they had such a clever answer. But they said it was our moon, which is not the case.

But you probably know that it is a moon called Callisto. Yes. Tell us about that moon. Callisto is one of the four big moons of Jupiter, of one of the so-called Galilean satellites. It's the outermost. And it is closest in size to Mercury. It's a little bit smaller than Mercury. Mercury radius about 2,440 kilometers. Callisto radius about 2,408 kilometers. There are two moons that are larger

than Mercury, Titan and Ganymede, both more than 100 kilometers bigger in radius than Mercury. Qualifications to be a planet are somewhat flexible nowadays. I guess they're not flexible. No, not... They're not at all flexible. Well, they're not for moons. I mean, natural satellites or moons orbit other planets. So as soon as you determine that... Once you're orbiting a bigger body, you're hard-pressed to get planet designation. But who knows? It's a somewhat arbitrary definition. We got another couple of cute facts. In fact, we got quite a few from a bunch of listeners. Eric O'Day said it's only a six-kilometer difference between Callisto and Mercury,

and that's less than the 3% difference. There were a whole bunch of people who said that Ganymede is the closest in mass to Mercury because Callisto is, I guess, quite a bit less massive than Mercury is, much less dense. Yeah, I mean, they both are. So Ganymede gets closer because it's bigger, also gets closer because it has a higher density. But Mercury, having a big iron core, making up a lot of it, and rocky body is much, much denser and thus has much higher mass. Whereas the Galilean satellites, particularly Ganymede, Callisto, they're mixes of water ice and rock and much lower density. Well, nobody that I've mentioned so far is the winner.

Our winner is longtime listener, but I think first-time winner, Courtney Katz of Telford, Pennsylvania. She indeed said Callisto. And the way it works is everybody who gets the answer right, we then throw it into random.org, which is a pretty cool website if you need a random number. And who doesn't now and then? We let random.org determine who among those people is the winner. And so, Courtney, congratulations. You are going to get that beautiful Planetary Radio t-shirt. Maybe you'll get one of those first women's styles ones that we now make available. And a, say it with me, a rubber asteroid.

A Planetary Society rubber asteroid. Don't ask how that got started. Rubber Asteroid. The Planetary Society Rubber Asteroid. Don't ask how that got started. And a 200-point itelescope.net account. It's a nonprofit network of telescopes around the world based in Australia. Courtney will be able to use it, use those telescopes all over the world to point them anywhere she wants to. So congratulations, Courtney. We also heard from Mel Powell in Sherman Oaks, California. He says, Callisto has always struck me as the solar system object that most resembles

a disco ball. He says, I make no judgment on that, good or bad. It's just a fascinating looking object. Well, thank you, Mel. Enjoy the Bee Gees. Shall we move on to the new question? Please. About staying alive. Actually, it has nothing to do with any form of staying alive. What was the first star to be photographed besides the sun? First star to be photographed besides the sun. Hint, it is also used or has been used to define zero magnitude on the apparent brightness scale. And I may or may not discuss it later in my class today.

He will. He's going to. You watch. That's a great one. So how do people enter? Go to planetary.org slash radio contest. You have this time until the 14th. That would be the 14th of February at 8 a.m. Pacific time to get your answer in. And good luck. It's that same prize package that we just talked about. I'm done. All right,

everybody, go out there, look up the night sky, and think about what you would say if bright lights were facing you from every direction. Thank you, and good night. I'd say what? Again? He's Bruce Fetz, the Director of Science and Technology for the Planetary Society, who joins us every week, not here, but joins us every week for What's Up. Planetary Radio is produced by the Planetary

Society in Pasadena, California. It is made possible by its hardy members. Daniel Gunn is our associate producer. Josh Doyle composed our theme, which was arranged and performed by Peter hearty members. Danielle Gunn is our associate producer. Josh Doyle composed our theme, which was arranged and performed by Peter Schlosser. I'm Matt Kaplan. Clear skies.