Imagine a future where the Perseverance Rover actually found definitive evidence of life on Mars. What would happen next? The Explore Mars Society recently held a virtual discussion on this topic with NASA’s chief scientist Jim Green and astrobiologist Penelope Boston from NASA’s Ames Research Center. Hosted by Mat Kaplan of the Planetary Society’s Planetary Radio podcast, the panelists talked about the current evidence for chemistry associated with life on Mars, what we can learn from life in extreme environments on Earth, and how finding evidence of life on Mars would change the world.

You can watch thefull presentation on YouTube.

Jim Green:The results of finding microbes might be as revolutionary as cracking DNA. That is awaiting us with this kind of discovery if we do indeed find microbial life on Mars, I think.

Penny Boston:The entire community would go into a frenzy of trying to test whatever features this potential life would have.

Jim Green:Hi, I’m Jim Green, NASA Chief Scientist. On this season of Gravity Assist we’re looking for life beyond Earth.

Jim Green:Recently, I was invited to speak at a very special virtual event that really dug deep into the question of life on Mars, but in particular, what would happen if we found it there? The event was sponsored by Explore Mars, and hosted by Mat Kaplan. You may know Mat since he’s also the host of Planetary Radio. Mat facilitated the conversation between me and a really fantastic astrobiologist and good friend of mine, Dr. Penny Boston from the Ames Research Center. Penny has traveled the world and has found all kinds of exotic life hidden in caves; some real extremophiles. Here’s a slightly edited version of that conversation and I hope you will enjoy it.

Mat Kaplan:Let me set the stage for today’s conversation with a hypothetical. We’ve jumped forward to 2024. A rover named Perseverance, that we’ll be talking more about momentarily, has been rolling across Mars for three years. Another visitor from Earth, a more recent arrival, named Rosalind Franklin, has been pulling up samples from below the surface of Mars. NASA and the European Space Agency have just announced a joint press conference that is going to reveal images and other data indicating that we just may have found strong evidence of life. Will this news, as my boss Bill Nye likes to say, change everything? What do we do next and how will it affect plans to send men and women to Mars?

Mat Kaplan:But I’m getting ahead of myself. So hold that thought for now as we meet two very distinguished guests that will be joining me here. I really can’t think of anyone else. I would rather have onboard to talk about this topic. Beginning with Dr. Penelope Boston. She is the Senior Advisor for Science Integration at NASA Ames Research Center in Silicon Valley. Penny’s personal expertise is the geomicrobiology of extreme earth environments, especially caves and mines and astrobiology. As a lifelong human space exploration advocate, she co-founded the Case for Mars conferences in the 1980s and 1990s. That makes her a founding member of the Mars Underground as well.

Mat Kaplan:She’s a member of Explore Mars. She looks pretty great in a fake space suit. She earned her Ph.D. in Microbiology at the University of Colorado, Boulder. She was, ’til recently, the Director of the NASA Astrobiology Institute based at Ames. And as a former professor and chair of the Department of Earth and Environmental Science at the New Mexico Institute for Mining and Technology. Also, the former associate director of the National Cave and Karst Research Institute. Welcome Penny.

Penny Boston:Thank you. Great to be here.

Mat Kaplan:Dr. Jim Green is the NASA Chief Scientist. He received his Ph.D. in Space Physics from the University of Iowa in 1979 and has worked for NASA ever since. That included 12 years as the director of the Planetary Science Division at NASA Headquarters. Under his leadership, more than a dozen planetary missions were successfully executed including the Curiosity rover and Insight lander, both of which are still quite active and delivering great science on Mars. Jim is NASA’s representative on the COSPAR Planetary Protection Panel where planetary protection guidelines are created and agreed to internationally. COSPAR, that’s the Committee on Space Research. In 19, excuse me. 1915? You’re not that old, Jim.

Jim Green:No, I’m not. [Laughing].

Mat Kaplan:In 2015, Jim coordinated NASA’s involvement in one of my favorite movies, The Martian.

Jim Green:[Laughing]

Mat Kaplan:Talk about infecting a planet. By the way, he also hosts the excellent NASA podcast called Gravity Assist. Welcome, Jim.

Jim Green:Thank you very much, Mat. I’m delighted to be here.

Mat Kaplan:So let’s back up a little bit and talk about the current status of exploration on Mars now and what’s going to be happening there, well, in less than a year now with the arrival of this new rover. Tell us, what’s the status of Perseverance?

Jim Green:Well, Mat, Perseverance is actually moving forward. It’s all down at the Cape and in fact the radio isotope power system is already connected. It’s checked out in many ways. It still has a number of things to do yet but we’re making great progress. So, it is on track for a July 17th open window for us to be able to launch. And that’s when that highway opens up for the next three weeks that can get us to Mars.

Mat Kaplan:This is like almost everything NASA sends around the solar system nowadays an international effort, right?

Jim Green:It is and indeed. This particular rover has got fabulous set of instruments where we have participation from Spain on a, on a weather system. We have Norway having a ground penetrating radar. We have the French working with us on some really great camera and laser systems. And we have an Italian retro reflector. But the whole point of this particular mission is, really, at the end of the arm. This is where we have high resolution images that we wanna be able to really look at the rock record and then make decisions in terms of creating cores. It’s got a core at the very end of it.

Jim Green:What these cores look like, it’s a, they’re like a piece of chalk in size or, or for those that are young enough that don’t really understand what you know, chalks and chalkboards were all about and their education, like a Crayola crayon, you know, one of the large sizes. Once those cores are made, they’re, they’re stuck indeed and, into an aluminum sleeve and then dropped on the surface for then later pickup and bring back.

Jim Green:So by the end of that decade, the 2020s, we hope to be able to have these samples back in our Bio Level 4 facility and begin the process of really looking through them to determine their viability and allowing scientists to get access to them for further research. So we’re doing great.

Mat Kaplan:And even though she resembles her sister on Mars, Curiosity, you’ve given at least a couple of examples in that image and with those cores, especially, of the new capabilities that Perseverance is bringing to the Red Planet. Pretty powerful machine, isn’t it?

Jim Green:Oh, it absolutely is. And the rock record is so important to us, you know. We know that Mars was a blue planet early on in its history. It went through rapid climate change. It was a blue planet during the time we know Earth had life started on it. And so maybe life started on Mars, too. And so we’re really quite excited about going there and interrogating that, being able to bring back those samples and look at them. You know, for all the minerals we have here on Earth, there are hundreds of minerals for which life is such a key part of that create those minerals. And, you know, so if we can find the right set of information, indeed that press conference you talked about would be really lively.

Mat Kaplan:So, sample return. And you know, I often refer to it as the holy grail of robotic exploration of, of Mars and could be for other places as well.

Jim Green:This was how we envision right now working with our international community to be able to get those samples back and it all requires NASA landing a Mars ascent vehicle. We then have fetch rovers that pick up those samples that we laid on the ground and deliver those. And then we launch off of Mars, those samples, in a, a container, and then that container goes into orbit for which then ESA satellite will come down using ion propulsion into lower, low Mars orbit. Pick those samples up and then bring them back to Earth. It’s indeed a, a multinational effort and the planning is going real well.

Mat Kaplan:Penny, you’re a long time Martian. What’s it going to mean to scientists like you to get those samples back here and into our nice big labs on Earth?

Penny Boston:Well, you know as you say Mat, it’s been a holy grail for many decades and pretty much my whole career. I’m sure that’s true for a lot of us. The opportunity to actually get our lab facilities here on Earth to bring all of their power to bear on samples is a new step really, in, in marching forward to be able to analyze Mars materials. The missions that we’ve had so far and the ones to come are magnificent. But there’s only a certain amount that you can smash onto a spacecraft and a lander and a rover before you run out of power and mass and all of that. And so the ability to do these really in-detail studies of the geochemistry, the mineralogy, the foundational bedrock materials, perhaps even some of the fine materials on Mars, will give us insights into the climate history of that planet which is very important to our understanding of climate in general on our own planet and beyond. And also potentially allow us to look at organic materials and various other things that may be significant for the potential history of any life that may have arisen on Mars.

Mat Kaplan:Jim, I wanna get back to you. I gave short shrift to all of the success we’ve already seen on Mars with two active spacecraft on the surface and that flotilla on orbit above the planet. Where are we in what we’ve learned? I mean, we found the water. Are we still following it? And what else have we found?

Jim Green:That’s a really great question in the sense that you know, there are more, there’s more to it than just following the water. You know, we’ve seen evidence of water all over the place on Mars, that’s clear. We’ve seen what we call, a recurring slope lineae where water may actually be pouring down the sides of craters in a seasonal way. This is during a time period during indeed that summer, where, where the sunlight shines on the crater walls, perhaps it sublimated water plug that’s sitting, holding back water in an aquifer and then that water pours out and runs down the slopes.

Jim Green:We’ve measured that. We know it’s water. Now, some of these actually may be drifts of of dust and, and, and therefore producing some discoloration. But there’s so much of it and there’s so many places where, where it’s occurring. You know, we’re pretty convinced that that indeed there is a significant amount of water locked inside the planet. Now, in addition to that, Mars seems to be emitting what we would call, traces of life gases like methane and like oxygen.

Mat Kaplan:I’m knocking on wood.

Jim Green:Yeah. Right. [Laughing]. And indeed, although those things can be generated abiotically, for the methane, we’ve been observing methane from telescopes on earth since the early 2000s but now with Curiosity making those measurements directly over and over again, we do see that seasonal bloom, what we’d call this rush of methane coming out. Although it’s still a trace gas, you know, parts per billion we’re talking about. That is coming from underneath the surface.

Jim Green:Now, that could be generated abiotically. It requires water, requires certain minerals and a heat source like magma or it could be old methane from old life in the past that has also been trapped over time and is, is being released. Or indeed it could be an indication of life there today in the aquifers, is what we would think. So those trace gases now are extremely important. We’re making fabulous measurement of those.

Mat Kaplan:Both for methane and oxygen, there’ve been some conflicting data, hasn’t there? Depending on the observer?

Jim Green:Yeah. Indeed, the oxygen observations that we just released over the last several months is a, is a long-term trend. It’s about five years worth of observations. And it’s a surprising trend. You know, as the planet goes through, its seasonal cycle, we expect during the winter because it’s so cold that a lot of the atmospheric gases, in particular, the trace gases, will collapse down under the surface. And then as it warms up, it, it, it actually then releases those. And what we’re finding is an excess of oxygen during, during certain times. And then at other times we see that the oxygen actually is being removed.

Jim Green:So this has really caused quite a puzzle. We’ve had many scientists really working, trying to figure out what are the, abiotic, in other words, the non-biological reasons that this is happening and we really haven’t come up with a good explanation. So the oxygen observations are really one we wanna stay abreast of and see what Curiosity is gonna find in the future.

Mat Kaplan:Penny, have we seen evidence other than what Jim has just talked about that could indicate biological activity or at least past biological activity up there?

Penny Boston:Well, you know, so far we haven’t had the opportunity to closely examine materials getting back to our previous discussion about sample return. But what we have been able to do, of course, is hook up what we understand about extreme environments on Earth and try to tease out the parts of those environments that are relevant to Mars. It’s pretty clear we have nowhere on earth that is just like Mars; it’s a very, very challenging environment. But we have challenging environments on Earth that have components that really go into that Mars picture.

Penny Boston:And so microorganisms in their vast diversity, they’re unbelievable diversity on this planet have adapted to, you know, wild variety of conditions. Many of them are the conditions that we see in the Mars surface. And particularly of course from my point of view as someone very interested in, in the subsurface, both near and deep subsurface, where there’s more protection from some of the nasty things that you get on the, on the Mars surface.

Penny Boston:So I think that the importance of the gases that Jim has just been articulating is really because the atmosphere of a planet is its breath, essentially. And the breath of life on earth is very, very clear. We have a very complicated atmospheric spectrum, which is, the sum total of all of the complex gases that life on our planet puts out. When we’re looking at a planet like Mars, if we’re looking at life that has been, not as ro- globally, as it is here on earth for a long time, that is something of a relic biosphere.

Penny Boston:Then we would expect to see a much more subdued signal. But the fact that there is this oxygen, um variability and the fact that we see these traces of methane, are very exciting. Because what that might say about life is that, if it exists in a subsurface, there’s a certain leak rate just like we have with spacesuits and spacecraft and Earth itself. And that we may be catching little whiffs of what’s going on underneath. In any case, whether or not it’s biology or it’s non-biology, when you have, a life bearing solar system like ours, in my view, every planet matters to understanding that life even if that life only occurs on one planet. And of course we certainly hope that it occurs on Mars or has occurred on Mars as well as other places in the solar system.

Mat Kaplan: Penny, you have spent a good part of your life going to places most of us would not wanna, go looking for how life has found a way to survive. One of those more milder locations. I remember being with you in Carlsbad Caverns and you pointed to a spot on the wall and you said, “You see that? That’s life eating copper.” So it does sure look like the enormous variety of extremophiles that we find on our planet, It’s gotta give you some encouragement, right?

Penny Boston:Oh, very much. Even though I, I’m a Mars fan for my entire life, of course I have an eye on the other potential habitats. And I think that the fact that we have organisms that appear to be able to tolerate almost everything including high radiation and organisms that have been retrieved from, you know, space exposure and complete desiccation. And, living amongst metals that we find toxic but they’re busy using inorganic chemistry to make those into energy sources, makes me really understand the, the sweep of what our type of life — meaning organic carbon, you know, water matrix is capable of — it’s really quite extraordinary.

Mat Kaplan:Life as we know it. Yeah.

Penny Boston:Yeah, life as we know it. And of course, you know, many of us consider life as we don’t know it and that life as we don’t know it extends to other ways of making life even out of organic carbon. So there are, there are people thinking about other alternative sets of chemistry that might work on other planets. But from the point of view of Mars, my conviction is that we’re really looking for carbon-based life in a water matrix because Mars is not all that different from Earth.

Penny Boston:And certainly as Jim pointed out, early in its history, it was much more similar. And so that early childhood of our rocky terrestrial planets together seems to me very significant. And even Venus in its current state which is quite inhospitable to life as we understand it, but its early history may have also shared in, in a habitable zone. So it’s not, not just Mars alone that is compelling but really Mars as this beautiful red jewel within this entire spectrum. This entire crown of jewels that we have in our solar system and, and what they offer for life.

Mat Kaplan:Have your, your studies and, and what we’ve learned from others in looking for biosignatures, that, that key term. Has it led you to the point where you think that if we had life staring us in the face, we would, we would recognize it?

Penny Boston:Well, yes, maybe. the slide that was just put up shows a variety. And this of course is for my, from my own work. All of these colorful and drippy gooey things that you see are all examples of microbes, as tiny as they are, but making major changes in the rock and mineral environments that they live in. They orange stuff that you see that looks sort of like a pizza or the surface of Io, that’s all rock breakdown material that’s been chewed through by organisms that use manganese and iron, rather than, you know, eating hamburgers for lunch, they eat rock.

Mat Kaplan: Wow.

Penny Boston:And they use those minerals and then they poop out, so to speak, all of this fluffy stuff. And so they’re, you know, they’re major geological agents on Earth but it shows that they can make their living off a geological source. You can see the screaming blue patch that one of my French colleagues is standing by sort of in the middle lower part of the, of the screen. And you can see an example of the same process. You were talking, Mat, about the copper material that I showed you. These are organisms all over the world.

Penny Boston:They’re different and very unrelated but they still are able to do the same thing. And so, that makes me even more excited because it doesn’t have to be the same organisms. It’s finding a pathway of organisms in different places that can use the same energy sources. And so, to me, that seems like an encouraging sign for extraterrestrial life.

Mat Kaplan:Jim, on a jump back now to that hypothetical that I posed of the outset. That press conference which you would very likely be a part of, as I hope you’re still on the job in 2024. You’ve got big news for us.

Jim Green:Right.

Mat Kaplan:What’s this going to mean if indeed we find evidence better than we’ve gotten in the past? I’m thinking of a certain meteorite ALH84001, that, that seems hard to argue with that maybe we have found at least evidence of past life on Mars. What’s that going to mean to us here on Earth?

Jim Green:Well, let me just mention, of course, there is, an important aspect of thinking about that future when we start that announcement. And that really boils down to looking at what’s happened in the past by analogies. The ALH84001 is a good one in the sense that we would organize that press conference. On that press conference, we would have the, the scientists that are announcing the discovery but also scientists that are a little skeptical. That announcement then would go out to the public and then there would be a period where the community of scientists would really dig into the results.

Jim Green:Perhaps if we’ve returned samples soon after that they would then be able to have those in the laboratory, et cetera, and really tease it out and then public reaction. And then an education has to go on to everyone in terms of the context of what, what this means. But if we just take that supposition that indeed in the long run it proves to be true and we have found that second genesis and it is on Mars, what does that mean? And here by analogy, I think we have to look at, perhaps, several. One, one comes to mind, is what Copernicus did.

Jim Green:At the time Copernicus was coming out with a theory that the planets went around the Sun and not everything went around the Earth. It changed the world view. Everyone, mentally, had to now rearrange their thoughts about their place in the solar system in the universe. And it had a profound effect. People thought, well, we are the center of the universe because everything goes around us and now they go around the Sun, just like the other planets. And then, to them that means, well, maybe there are other societies like us on other planets. This was a really profound change.

Jim Green:I think, indeed, we’re gonna have to come to grips with that. Many people because of our literature and our movies are, you know, all set to accept that there’s a second genesis out there. And in fact many scientists, and that would include me, think it’s almost inconceivable that there isn’t some sort of life out, not only in on in the solar system but certainly is certainly on other planets.

Jim Green:And so our worldview then, once again, will have to change. And I think it will change many different things. The, the results of finding microbes might be as revolutionary as cracking DNA. You know, the concept of what, what’s come out of microbiology, which is only a handful of decades old, has just been phenomenal. That is awaiting us with this kind of discovery if we do indeed find microbial life on Mars, I think.

Mat Kaplan:Penny, what would this mean to you and, and your colleagues, this announcement and the provision of this data?

Penny Boston:Well, you know, I spent my entire life doing this and so have many of my colleagues. So [laughing] I have dreamed about that happening in my lifetime. I hope it does. I’m trying to stay as healthy as possible to get the maximum chance. [Laughing]. And you know, the minute we got any kind of indication that there might be extant life or even extinct life, okay, ’cause I also do paleomicrobiology and I’m interested in the entire deep history of planets with life. The entire community would go into a frenzy of trying to test whatever features this potential life would have. And so there would be an enormous flourishing, maybe in directions that were already pursuing, maybe a new directions. It depends on what those results would find. And then I would throw one heck of a big party.

Mat Kaplan:[Laughing]. I’d like to attend that.

Jim Green:[Laughing]. Please invite me.

Penny Boston:I will.

Jim Green:[Laughing].

Mat Kaplan: We should get into a, the topic that topic maybe our, our sponsors here that explore Mars are most interested in after all, they are the humans to Mars people. And that is, what the possibility evidence for, not just pass but possibly existing life on Mars stuff that’s still kicking up its heels there today, would mean for sending humans there? Jim, you were a, a, a big contributor to that movie, “The Martian.”

Jim Green:Yes.

Mat Kaplan:It would not be a good idea for us to head there and, and plant poop potatoes, would it?

Jim Green:Uh uh. No. Actually, Curiosity has found the, the nitrogen, oxygen carbon, phosphorus and sulfur on Mars. All the right stuff. The soils are, are moist and indeed, there’s nitrates in the soils. Now, where Curiosity is sitting, turns out to have alkaline soils, not acidic. So what would grow better here would beans and asparagus. And, and, and I don’t know about you but if I had to eat two or three years’ worth of asparagus, I’d just take my helmet off and walk outside.

Penny Boston:[Laughing].

Mat Kaplan:[Laughing].

Jim Green:But I’m assuming — I could do the potatoes — I’m assuming, we all are assuming there’ll, there’ll be more acidic soils to elsewhere. And so indeed the analogies between Mars soils and Earth soils is really strong. That’s really quite important. If we found evidence for current life, that current life has to be below the surface. We haven’t found evidence of life on the surface. And for human exploration I think we’d have to talk about how we’re gonna share Mars, and I think we can share Mars.

Jim Green:There are many approaches unlike “The Martian” where the concept was, you land Ares 1 and the next time it’s Ares 2, Ares 3, Ares 4. We would plan to go to one particular area, perhaps 150- or 200-kilometer area called an exploration zone where we land in one part, live in another part and then have the ability of mobility to go around and perform a whole variety of scientific experiments but really confine ourselves to that part of Mars.

Jim Green:And in so doing then, it gives us a wonderful opportunity, perhaps over several decades of, of continuing to go there and continuing to build and develop things at that site. An opportunity to really learn and obtain a deep understanding of what Mars is all about. And then we can take it to the next step with that kind of knowledge. So I’m all for sharing Mars.

Jim Green:Now, you may know that many scientists, particularly Carl Sagan, thought that if we found microbes on Mars, we need to leave Mars alone and go to the, go to another body in the solar system. But, I think because life also has to evolve over time, the evolution of that life is going to be completely different than ours. And that gives us, I think, an opportunity to coexist. And, and those are some of the new ideas that are coming out now.

Mat Kaplan:Penny, what’s your view about all this? I mean, I think you wanna see boots on Mars as well. But you—

Penny Boston:I’d like to see my boots on Mars actually.

Jim Green:[Laughing].

Mat Kaplan:[Laughing]. Me too.

Penny Boston:But I’m going to be too old, I’m afraid. But, it’s something I’ve wrestled with my entire career because I have this desire for exploration for our species to go beyond other bodies in our solar system. And who knows, someday even out of our solar system in some number of hundreds of years. But at the same time, of course, I’m very, very aware of the deep ecology aspects of another biosphere. And this applies to Mars or any other biosphere that we may find in our solar system.

Penny Boston:And that is, how do we study it? How do we, perhaps, co-habit with it as Jim points out without doing damage to it? And in turn without doing damage to us. I think that many years ago, probably 25, when I first started writing about the Mars subsurface as being the best place to look for life on Mars, it was not taken very seriously. We knew a lot less about the planet at that time but we’ve plugged along on that theme and I think it’s become manifest that, that is the place, as Jim says, where we would have the highest chance of finding subsurface life, even if Mars once was covered in life at the surface.

Penny Boston:That the subsurface, in many cases, particularly even on Earth, is a refugium, a refuge for organisms when circumstances change on the surface. We see this in microorganisms and macro organisms. So there are caves with fish and invertebrates that have been separated for 20 million years from the surface and things of that sort. So I think that the expectation that I have is that any Mars life is going to be quite deep. And that helps us with this conundrum. Because as long as we don’t contaminate aquifers as we’re trying to get resources for human use then the surface Mars environment is very harsh.

Penny Boston:And while I wouldn’t call it entirely self-sterilizing, it will do a lot to reduce the plume of biological contaminants within some distance from a human colony. And then of course, if we want to study things like the slope lineae, these trickles of water, a briny water that Jim mentioned early on in our, in our discussions, those are juicy targets literally and figuratively.

Penny Boston:We can’t wait to get our hands on them, but our hands will not be our hands. Our hands will hopefully be sterilizable robotic sampling devices that we’ll be able to send out and bring those samples back for analysis. So there are ways to do this and you know, we’re living through it now with this pandemic that we’re all experiencing. How do we separate our activities from, in this case, a pathogen, but in the case of humans on Mars, how do we se-separate ourselves from potential organisms that are the Martians and keep all of us safe?

Penny Boston:And so all of these real world things are being worked out in real time. And as, as where you mentioned that Jim is on the COSPAR panel, that dates back to the 1950s and the early part of the space age. So it’s not like we just discovered that, oh, gee, there might be a problem. Many of us have served on panels and workshops and we’re writing about it all the time. So it’s very, very much foremost in our minds about how to do this safely. I think we can do it. I hope I’m not being naïve.

Mat Kaplan:Jim, I’m, I’m really glad that Penny brought us back to that COSPAR committee that, that where you are the planetary protection representative from NASA, from the United States. How is this being considered by the international community? These questions are protecting Mars but also wanting to go there and like have humans explore?

Jim Green:Well, indeed COSPAR over the years has looked at each and every one of the bodies in the solar system that were being considered by space agencies to go to. And indeed, early on, we didn’t know much about the Moon in terms of whether there’ll be pathogens there. And so consequently, those guidelines that came from the COSPAR committee, that the international community signed up to, meant that we, for, for a NASA perspective, wanted to implement a quarantine system.

Jim Green:So when samples came back from Apollo 11, you know, the astronauts went into quarantine and the samples went into quarantine. And then we went through our processes of indeed interrogating those and understanding what they are, what we had, whether there were pathogens, et cetera, watching the astronauts over a period of time. And then finally recognize that indeed we could have uncontained sample return from Mars. We didn’t need to go through the quarantine process.

Jim Green:And so then, that means the guidelines were revised. So the committee, indeed, takes it very seriously that as we learn new things about each of the bodies that, that the space agencies are planning to go to, we take that into account to modify those guidelines. And that’s been working really well.

Jim Green:In fact, just recently we took a good look at Phobos. And we recognized that Phobos indeed, one of the moons of Mars, we could actually back off some of the more stringent guidelines on returning samples. And so we’ve categorized Phobos as our location where we can have unrestricted Earth return of those samples. And the, and the Japanese-JAXA mission is, is being planned to go there and has many international connections and components to it. But that required for us to bring all the knowledge we knew about Phobos forward, and not consider it like Mars in a category of more restriction. And so we’re gonna continue to do that. And that process is working well.

Mat Kaplan: Penny, you touched on it. But it’s the question that Explore Mars, our CEO, Chris Carberry posed before we started this. And that is whether what we have learned about both, how we might handle isolating ourselves from life on Mars or anything else in the field of astrobiology might have helped prepare us to deal with the challenge that we’re facing around this planet right now. The pandemic. I mean, do you see any relationship there?

Penny Boston:Yes, I, I, I do. I think that one of the things that this horrible circumstance will maybe help is eventually in better public communication. You know, when you are trying to talk to people who are not microbiologists or scientists of some other sort about microbial life, it’s very hard to communicate the size of these individual entities, their capabilities and just how easily spread they are. You know, in many cases that’s very benign. There are many microorganisms that we need in our environment.

Penny Boston: They basically run a lot of the biogeochemical cycles on our own planet. So on balance, they’re beneficial. We only sort of noticed them on the broad scale when they’re deleterious. Like in the case of the COVID-19. But you can derive some lessons from this, you know, the fact that we have a new virus on the scene means, even though it’s related to other Earth viruses and similar to others in its group of coronaviruses, it’s many different properties. And so a lot of the scrambling that’s going on now in the medical and research communities is to try to figure out its properties. The way that we, that we do that in real time is orders of magnitude accelerated compared to what we would have been able to do with something like this even 20 years ago.

Mat Kaplan: Mm-hmm.

Penny Boston: So within mere weeks we had an entire genomic sequence for this RNA type of virus that was propagated around the world. The biggest issue is, you know, we are a world full of people with different traditions, different levels of technical sophistication and different access to communication. And so it’s the human response to that, that’s been the trickiest part. One of the things that I think is important to communicate is that microorganisms, for the most part, are benign and absolutely essential to us. And so one of the things I don’t want to see is an increase in sort of mindless germaphobia from this. And you know, that could be a natural outgrowth of this. But we are talking about studying microbial scaled life on another planet. Although, we’re mostly looking at bacterial size things.

Penny Boston: And if you look, if you look at a bacterium, you can probably line up maybe 80 or a 100 of them across the diameter of one of your hairs. But if I were going to put viruses across the diameter of your hair, I would probably put a thousand or 2000, right? So they’re even more minuscule. So I think we’re mostly focusing on bacteria-size organisms. So those are actually much easier to control and work with for the most part than the viruses, because the viruses are, are tinier than dust specks.

Penny Boston:Whereas the bacteria are much chunkier, you know? And so our, our methods of controlling bacteria and working with them in many ways are easier.

Jim Green:Yes. Penny, did a wonderful job explaining the various aspects of that. What’s critical also to understand is, you know, viruses aren’t considered alive. They really are cellular parasites. If I, if I were to describe them in some way and they, they invade the body and they have some genetic material associated with them, but in reality, for them to live and grow, they actually have to co-evolve with a host. And so when we think about bringing material back from Mars that is alive, that life has, perhaps, a second genesis, perhaps is related in some way to us in terms of the fact that it started in a similar environment like Earth, but it has a completely different evolutionary track. And so the current thinking is, um, yes, we’re going to quarantine those samples. Yes, there’ll be in, in what we call a Bio Level 4 facility, you know, where they handle anthrax and everything else and it will be closely monitored.

Jim Green:But I think as Penny points out, our ability to understand the, the microbiome and virus environment will allow us to those current tools to interrogate those samples and begin the process of releasing things to the science community, which will be really important to do because that’s where those laboratory equipment really comes into, into play. Many places around the world that will really tease out some of the most spectacular science in terms of really having a deep understanding of that planet, then we, then we can dream up today.

Mat Kaplan: Mm-hmm [affirmative].

Jim Green:So, those are all, those are all just right around the corner, you know. And, I’m, I’m hoping also to be to be around when we start cracking into that next generation.

Mat Kaplan: You and me and Penny, all of us and everybody watching this program, I am sure.

Jim Green:Now, I was alive and in high school at the time of the lunar landings and it was just, awe inspiring even with the grainy, yucky—

Penny Boston:Oh, yeah.

Jim Green:You know, black and white [TV.

Penny Boston:Yeah.

Jim Green:And so today we’re gonna be doing it in the high definition. And the colors will be spectacular ,and the shadows will be long, and it will be incredibly eerie but it will be just as inspirational. So everyone, you know, that hasn’t seen that original lunar landing of any of the Apollo astronauts, have really got a treat in store for them. And that’s coming up.

Mat Kaplan: What a great way for us to, to end this wonderful conversation. I wanna thank both of you. Um, there truly were no better people to be a part of this discussion of life on Mars and why, we, examples of life down here, are so excited about it. Thank you. Jim Green, NASA Chief Scientist. Thank you Penny Boston of NASA Ames, astrobiologist.

Penny Boston:Thank you. Thank you.

Mat Kaplan:And thanks to all of you for tuning in, for joining us for this a-and to Explore Mars for making it all happen and the great people there who have been helping us out. Wade, Janet, Chris Ron Sparkman, Adrianne. And keep looking up there at Mars. We’re there and we’re going back. Thanks for, again, for joining us. Have a great day and stay safe.

Penny Boston:Live long and prosper.

Jim Green:[Laughter]. Live long and prosper. Thanks Mat.

Mat Kaplan:My pleasure.

Penny Boston:Thanks Jim. Thanks Mat.

Jim Green:Take care, Penny.

Jim Green:That was really a great event. I had a fun time talking to Penny and Mat. You know, there’s so much more we have to learn about the possibility of life on Mars, and I can’t wait for the launch this July to the Red Planet of the Perseverance rover along with its traveling companion the Ingenuity helicopter. Tune in next week for more as I continue our quest for the search for life beyond Earth on Gravity Assist.

Credits:

Audio from the “Life on Mars” conversation provided by Explore Mars and the Planetary Society.

Lead producer: Elizabeth Landau

Audio engineer: Manny Cooper