Planetary Radio: Space Exploration, Astronomy and Science - Diving Into That Lake on Mars

Episode Date: August 1, 2018

Our world was rocked by last week’s announcement of good radar evidence for a liquid water “lake” under the Red Planet’s south pole.   Senior Editor Emily Lakdawalla introduces us to the story that is then taken up by two of host Mat Kaplan’s favorite Martians.  The Goddard Space Flight Center’s James Garvin headed NASA’s Mars exploration program, while NASA Ames astrobiologist Chris McKay co-founded the Mars Underground more than 35 years ago. Look up!  Mars is still close by, and the Perseid meteor shower is around the corner. Bruce Betts gives us the What’s Up lowdown. Learn more at:   http://www.planetary.org/multimedia/planetary-radio/show/2018/0801-2018-garvin-mckay-mars-lake.htmlLearn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

The best conversation you'll hear about that lake on Mars, this week on Planetary Radio. Welcome, I'm Matt Kaplan of the Planetary Society, with more of the human adventure across our solar system and beyond. No boast, I really think my conversation with Jim Garvin and Chris McKay about what's going on deep under the Red Planet's South Pole is amazing. They even came up with some new ways to investigate that supposed body of liquid water as we were speaking. Senior Editor Emily Lakdawalla will get us into the topic in a few seconds, but don't forget that we've also got Bruce waiting in the wings to deliver the goods on a still spectacular night sky. Along with the new space trivia contest, a really easy one this time.

Emily, a lake on Mars. You wrote about it in a terrific blog post that went up on July 25th at planetary.org. Of course, the world now is excited about this. Give us a recap. What found what on Mars? We discovered water on Mars again. Again. Again. Patrick, never.

So yeah, it seems like we discover water on Mars at least once a year. Journalists like me are a little bit jaded about water on Mars discoveries, but I saw a lot of scientists on Twitter saying, oh, boring, another water on Mars story. Wait, it's liquid? And that was the reaction in general. So the discovery was made by the Marsis radar sounder instrument on the venerable Mars Express spacecraft, the European spacecraft that's been in orbit since 2003. They used this ground penetrating radar instrument to find a very reflective horizon at the base of the South Polar Cap. And in the scientific paper, they laid out various explanations for what it could be.

But the most plausible explanation is a 20-kilometer-wide body of either liquid water or sludgy sediment. The catch is that it's buried deep below the ice. It's still very cold, so it would have to have a lot of salt in it, not just your typical ocean salt, but also salts of perchlorates and other nastier chemicals in order to keep it liquid at those temperatures. So still, though, it is a long-lasting liquid body of water on Mars, probably. We are still talking about only one instrument having detected this. Scientists would prefer that we had more than one way to detect it, but it was actually predicted

by another scientist about 30 years ago. So it's not implausible. Interesting. Yeah. I got that press release today about the work by that other scientist at the Planetary Science Institute who predicted this. That's Stephen Clifford. And they even acknowledged his work in their paper, of course, as one would in any scientific paper. So I think that's one of the reasons why even skeptical people like myself are viewing this with maybe slightly less than our usual skepticism, because it is totally physically plausible and predicted. It just hadn't been observed before. If this proves out, if we get other data that says, yep, it sure seems like there's something

liquid down there, is this something to be really excited about? Well, yes and no. If there is extant liquid water on Mars, and if life ever got started on Mars, and if it survived Mars's lengthy history, then this would be the kind of place that you would go look for extant life on Mars. All of that being said, there are much wetter places that are probably a lot less salty in the solar system that you could look for extant life, namely Europa and Saladus, maybe even Titan. It's sort of exciting for the possible story of present day life on Mars, but it doesn't really tell you anything about those more fundamental questions of whether it ever got started there. And it's not really the best place to look either in terms of answering that question because it's hard to get to and it would be a pretty nasty environment.

Still, it does make it more plausible that life could have survived down to the present day on Mars, again, if it ever got started there. And that's still a really big if. All right, Emily, that is a terrific introduction to today's pretty special topic. And we'll pick it up again in a moment with Jim Garvin and Chris McKay. My pleasure, Matt. It's Emily Lachtwala, Senior Editor and Planetary Evangelist for the Planetary Society. We'll talk to her again soon. Jim Garvin is chief scientist at NASA's Goddard Space Flight Center. He used to lead the agency's Mars exploration program and then went on to serving as chief scientist for all of NASA.

You last heard him on our show when I talked with a terrific panel at the Humans to Mars conference last May. His colleague, Chris McKay, has joined us many times. Chris is a senior scientist at NASA's Ames Research Center in California's Silicon Valley. He was a founder of the self-named Mars Underground back in the early 1980s. Now he's one of our planet's best-known astrobiologists. I'm sorry the sound quality isn't better, but I bet you won't mind it when you hear what they have to say. Gentlemen, it is such a pleasure to get both of you back on the

show. You are two of my favorite Martians. It is very appropriate to be talking to you today about this big announcement that was just made a week ago as we speak. Before we get into some of the details, if this data, if the interpretation of this data turns out to be correct, and we are looking at a lake or liquid water a kilometer and a half below the surface of the Martian South Pole, what does this mean for further exploration of Mars and maybe for life on Mars? Chris, you want to go first? For astrobiology, this is really big news because this is potentially a large body of water. It may be slightly saline, but that's okay.

Our experience in Antarctica suggests that sub-ice lakes like this can be rich in life. It's exciting. that sub-ice lakes like this can be rich in life. It's exciting. The challenge it raises, and this is a big challenge, is getting down one and a half kilometers of ice. Jim, your reaction, if this turns out to be exactly what the scientists behind Mars think it is? I think a little differently in the sense that I say, why not?

Why have we not seen this phase change of liquid water somewhere in the Martian stratigraphic column? We've been looking for, you know, 18 years with exceptional instruments. I say, finally, we're starting to see evidence of what we thought we would see. And that means these methods that we put in place so long ago are bearing fruit. And then the question becomes, so why not in other locales? And what's hiding the Mars liquid water story in the environment we see in that upper multi-kilometer crust of Mars? So I'm bullish on this, meaning it's a tip of a liquid waterberg on Mars for what we may be able to see if we look harder with other instruments, possibly even future ones that some of us have been dreaming of for decades of super high resolution synthetic aperture radars that would look in the upper 10 meters of this icy crustal column and go beyond. So I say, great job, lots of work to do so we can follow this liquid water story to the

astrobiology that Chris knows about. Jim, you're a radar guy, among other things. Tell us very briefly how this radar managed to look a kilometer and a half, a mile below the South Pole and find liquid water. Sounding radars were actually used on the Apollo command service module back in the 70s. And they did holographic film recording of signals that went kilometers deep. And so the methods have been well known in geophysics as potentially revealing. It wasn't until Marsis on Mars Express and its cousin, Charade, on our Mars Reconnaissance Orbiter,

that we've implemented those at Mars, where the whole radar principles are challenged by the Martian ionosphere and other factors that we have to kind of remove, like noise cancellation or noise removal. But the beauty of this is these are sounding radars. They're not the picture-taking synthetic aperture radars that light up when we see buried river channels under North Africa, for example, as the shuttle imaging radar is done. What's beautiful about it is it allows us to see deep on the basis of the wavelength that we're transmitting, literally down to tens of meters long radio wavelengths that allow us, with large antennas that span 40 meters on the Mars Express spacecraft, to sense very deep. And what they do is they're measuring changes in the electrical properties of the material we're sounding into. And those properties are really as a function of the electrical conductivity, porosity, and other chemical constituents.

Those properties we call the dielectric permittivity of the material. And when it changes from soil and rock or regular ice factors of two, three, four, five, to factors three to 10 to 50 times more, we start to get excited about seeing phases that could be liquid. And that's what this brilliant team from Italy has done with Marsis over this South Polar Layer Terrain. They use those techniques to ferret out that potential at this very large scale. And so it's a brilliant detection. It's not without controversy. Many things in volumetric sounding or even in medicine, when we look inside our bodies, for example, we always wonder, oh, are we really seeing that in an MRI or an XCT? But in this case, it's one of the most reasonable

interpretations of what these colleagues have put together. So it's exciting, but it's one of the most reasonable interpretations of what these colleagues have put together. So it's exciting, but it's also frustrating it's so deep and still controversial. I'll pick up on that, Matt, because Jim's final point there is an important one, which is these radar methods are elegant and very powerful, but there's always a residual ambiguity. Is this really what we're seeing? That always haunts me, of course. And then, of course, if we're going to do astrobiology, we need to not just see it. We need to get a piece of it.

We need to get a sample of it. So I think this becomes a very strong argument for deep drilling. We're seeing these interesting things in the subsurface of Mars. The radar can tell us that it's there and where it is, but we're going to have to drill down to, A, confirm the radar, it really is what the radar says it is, and then, B, get a sample and look to see if it's got evidence of life in it. So let's push for deep drilling. Let's also look shallow at the scales that our exploration, deep drilling or robot over lander based,

can operate at. And those scales are tens of meters, not kilometers. And, you know, Chris and colleagues do that kind of thing in deserts and the dry valleys of Antarctica here on Earth and other places. And so we have now, thanks to this, the prospects of connecting the dots from deep to shallow with advanced techniques that are now ready for Mars. These elegant polar metric imaging radar methods that we've been thinking about for two decades, I think this says we've got to do those too, because they're going to point us to where a prison team would want to go and start that drilling beyond a couple of meters. Chris, were you surprised by this finding? I mean, as Emily mentioned when we talked to her a few minutes ago, there was actually a prediction that this kind of deposit might be under the poles

more than 30 years ago now by Stephen Clifford at the Planetary Science Institute. That's right. That's right. In some sense, Steve's paper laid out the logic for this, but we'd spent a long time looking and hadn't seen anything. I had given up. And so I was seen. So a prediction doesn't count for much. Nothing speaks to reality like data does. And now we've got some data. So I was surprised. I was pleasantly surprised. And now I'm eager to follow up on it. Jim, I was, even though I understand it, I'm still blown away by the fact that they can actually generate a cross section looking under the Martian surface using this radar. And you can

see this pocket of liquid water or whatever it is, slush. It seems like such a sophisticated technology. Well, Matt, I think, you know, as Chris was saying, that's the beauty of this. It may seem like something out of Star Trek, and yet we've been doing it for 40 years. We sounded into the basin known as Mare Serenitatis on the moon with an optical version of this kind of thing in the 1970s. And now we've just refined it and taken it to Mars. It's actually been used in lunar orbit more recently. And so the beauty of it is we've tailored it, and thanks to other datasets from like the MOLA set for the topography of Mars, we can remove some of the noisy stuff and make it even better.

And this team put together, if you will, a mesh of these measurements in a way that would allow a more refined interpretation at the scale of this 20-kilometer, let's call it a high dielectric zone, as Chris was saying, that could be interpreted as liquid water, briny water, or even other phases in super metal-rich salts can produce this kind of signature. Again, it's been a long time coming, so we're all really dazzled. And the question is, what next? And I think that's where the beauty of it is. Together with the recent paper by Dundas with the cliffside exposures of water ice in the shallow stratigraphy of Mars and what Phoenix has seen, this points to this world that I like to describe as maybe a cryo-ocean world today that gives us more prospects

for the astrobiology that the colleagues like Chris and others want to pursue. You know, Matt, this is an interesting story, discovery by radar, then a potential following up. And it reminds me of an almost identical experience we had in the dry valleys of Antarctica. And Jim's comment about the dry valleys triggered that memory. There was a lake in Antarctica called Lake Vida, which for decades we thought was frozen solid all the way to the ground, just a block of ice. And then a radar pass over the lake revealed a flat conducting liquid, presumably liquid salty surface, just like this. First clue that something was different than we thought was radar. We proposed to go down and drill into it, which we did, and it was underneath 20 meters of ice, so not as deep. But once we drilled

into it, we found that there was a brine, a salty water solution, and there was organisms living in it. And it smelled awful or wonderful, depending on your perspective. And so in a little microcosm or a micro version, we repeated this same thing that we hope to do on Mars, discover something with radar, drill down and look at its biology. So I'm very excited about this. And it directly maps into our experience in Antarctica. We can point to places in Antarctica and say, hey, here's the same story. Chris, you said something right up front that caught my ear. You said the slightly saline or slightly salty. What I've heard is that this is, if it is liquid, it may be really nasty with salts, with those perchlorates.

Is this the kind of environment, do you think, warm, lazy microbes of a few billion years ago on Mars could have evolved to thrive in if it is as salty, as nasty as it may be? Well, that's a really good point, Matt, and it depends on the salt. If it's the normal salt, sodium chloride, organisms are happy with it completely saturated. You can put as much salt as you can, and it doesn't bother the organism. Perchlorate, on the other hand, that's a different story and it can easily overwhelm the organisms and they can't live. No life forms that we know can live in saturated perchlorate salts. Our understanding of perchlorate on Mars is limited, but what we know would suggest that

it's mostly on the surface. And the data that supports that is the absence of high perchlorate in the meteorites from Mars. So we see perchlorate on the surface, but we don't see high perchlorate in the meteorites, which come from depth. So it could be, if we're optimistic, that yes, this lake is salty, but it's not been affected by the perchlorate issue that we see on the surface, and that the salt is more likely to be sodium chloride, normal salt, which is that we see on the surface, and that the salt is more likely to be sodium chloride, normal salt, which is what we see in the meteorite. So I'm guardedly optimistic that although it will be salty, it'll be the right kind of salt for life. Well, that gives me hope. Jim, anything to add? Well, I want to come back to, Matt, the whole connectivity that I think

Chris spoke to so well. So those detections on Earth were done at high spatial resolution, at scales where you could go there and narrow down right where to go. We've had this first elegant detection by the Marses team at 20 kilometer scales with a few pixels across the region where the putative lake is, the hypersoundly lake, hopefully, you know, with sodium chloride, as Chris said. there's a lot more work to be done. Using our much higher resolution, but shallower penetrating radar known as SHARAD, provided by Italy on our Mars Reconnaissance Orbiter, we could zone in and make a much finer scale mesh of places that are not as deep, but we could see more fine scale stratigraphy and maybe more of these zones. And an imaging radar operating at NADR with the kinds of sensitivity they provide,

the kinds that have been used flying over the Antarctic or the North African deserts, could see down at scales of meters, and then we could zone in sort of a type of drilling system that's, you know, in the near term, extremely exciting on Mars, you know, maybe 10 meters, and get to some of these zones if they actually connect from depth to the surface. And that's a big question, the connectivity of this cycle of ice-water in that sedimentary crust of Mars that actually gets to your question about, and Chris's point about perchlorites. If they're a surface phenomenon now and not at depth, that has a big implication for the astrobiology and also for how Mars has worked its photography.

So, again, this is catalyst for thinking in a new way about some old ideas that Steve Clifford and others put forth and others using this data. And I suspect we're going to find more of these kinds of phenomena in the radar data we're collecting now. And that will motivate this next step to move to both drilling and a higher resolution kind of radar at Mars. Have you heard that there is thinking now that MRO should use that Charade instrument, that radar, to scan these same areas? Or has that already happened? Well, it's happened to some extent. And the team and many members of the team who I was lucky enough to help select a few years ago, so they're very good women ander, which we all love on the surface, and, of course, has the CRISM hyperspectral instrument from Scott and Murchie.

They're in high demand, and so we have to balance those demands. But allowing the charade radar to produce a grid, a mesh, over this part of the south polar layer terrain or equivalent areas in the north when the geometry favors, could be a very good experiment for the team. And some of those teammates, Bruce Campbell, Jack Holt, others from the Mars team as well, Roberto Segui, are already talking about that. So I suspect we'll see that next step. And plus, in 2020, Mars will be close enough to Earth for the Arecibo radio telescope to use its big S-band radar to look maybe five or 10 meters deep in wherever the sub-radar point is to look at what happens shallowly. Could we see things like this in those wavelengths,

those gigahertz frequency wavelengths, in new places now that we know this is a possibility? So again, great time for radar and connecting a task to biology is always good. Jim, I have a question for you. You're talking about using other instruments, and it made me think of one phenomenon we see in Antarctica. When we have these polar lakes beneath the polar ice, the surface of the polar plateau becomes exceptionally flat because, of course, it's floating on this lake deep below. Could you use the MOLA data to go back over this zone and see if the surface of the plateau on Mars is flat as well. This provides indirect evidence of hydrostatic equilibrium ice floating on water. And Jim, before you go on, you've mentioned MOLA a couple of times, and Chris has just brought it

up. This is the laser altimeter, right? Right. MOLA is the Mars orbiting laser altimeter that we flew on the Mars Global Surveyor, operating for 700 million pulses and made a subkilometer geodetic quality topographic grid of Mars. And what's unique about that, and Chris asked the perfect question, its quality of vertical accuracy is so good that it allows us to see extremely subtle differences. And so when things are hyperflat, if that's even a word, we can detect that relative to other subtle ramps and tilts that could be a phenomenon at both short and long wavelength. And that's the beauty of MOLA. We can make beautiful local areas of topographic maps from high rise that we use to drive rovers, wonderful stuff, but

they're not in a geodetic framework. Whereas what Chris is saying, using that laser altimeter data that we've already collected over these regions, these South Polar layered deposits, the North, others, we can see how flat they are. And if they're so flat, as Chris is saying, to demonstrate this potential equilibrium, And if they're so flat, as Chris is saying, to demonstrate this potential equilibrium, that could be a further indicator that there is this water story at depth that is making things flat. And by the way, the MOLA team early in the Mars Global Survey, as Chris will probably recall, detected areas that were as flat as the flattest river delta systems on Earth, which are unbelievably flat.

And if you look at Ganges Brahmaputra, you go 100 miles and the relief is changed by a foot or two. It's hard to even measure that. Likewise in the Mississippi and Irrawaddy and others. So we saw those on Mars. And that fundamentally changed our thinking about some of these big dust bowl regions on Mars. Now, applying that to the layered terrain where this detection has been made is a great idea. And future instruments, ironically, that people have been proposing in our competitive marketplace for science have proposed to do 10 or 20 times better than MOLA on a global scale to look for

some of these topographic fingerprints of processes that are at depth that could relate to water or, of course, other things. So the potential of this triggering thought, deep drilling, radars, lasers, re-look at data, is really the beauty of science, is that response function by the community and the creative folks who work every day at this. Yeah, this is really exciting, Jim. And I just want to point out that the famous subglacial lake in Antarctica Lake Vostok it's under three and a half kilometers of ice and it creates a flatness on the surface that's distinct in the data so the idea of going back to the to the really wonderful MOLA data set and seeing if

we've got these flat spots over these lakes would really be a sweet confirmation of this of this effect and it really be a sweet confirmation of this effect. And it would be a nice, again, parallel to Earth. Well, one of the things we can do, Chris, which is the beauty of having these now phenomenal legacy data sets, is combine the molar data with the stereoscopic coverage of the context imager on the Mars Reconnaissance Orbiter, which has covered about 98% of Mars now, and something many tens of percent in stereo. So making stereo models of these regions and then tying them together with the MOLA data would literally dial down the spatial sampling. And

those techniques on Earth, as you know, Chris, are used all the time and could be applied at Mars. So I think, again, this offers us a way of looking in other ways to explore the potential of this discovery. And then all the astrobiology that, Chris, you talked about, which to me is great. I just don't want those things growing in me. Wonderful as all this remote sensing is, it really is spectacular that we're able to do so much from a distance.

There is nothing like getting that direct evidence. Do we have the technology? Is the technology within reach for us to do the kind of drilling at the South Pole of Mars it would take to pull up some of this stuff? Well, that's a really good question, Matt. And on Earth, of course, we drill through kilometers of ice in Antarctica regularly. But that is a pretty large drill rig, and it's operated by a team of humans. So on Mars, right now, with robotic systems, the drills that we can send today are about a meter depth. So there's a big gap between what we can do on Earth drilling in ice

and what we could do on Mars. Now, it may be that through some clever technology, the robotic systems will catch up, but it may be that this is indeed a job for human exploration, that accessing a kilometer deep or one and a half kilometer deep lake on Mars is the scientific call for human exploration. This is what the humans are going to go do. I'd be happy to sign up for that job. I'd go too, as long as I could make a return trip.

Jim? Well, Matt, I was going to say, and I agree with Chris, and this is one of the reasons why our present trajectory with the Mars science led by the robots, with people returning to the moon, there's a connectivity potential. One of the things we could try out on the moon, not in big, vast ice reservoirs like we have here

would be to drill to a kilometer with human assistants and robots in a place off planet where we have to figure all of it out more autonomously more self-correctingly so the grid engineers can figure out okay now it works on the moon we test these ideas there which which are also fertile, but different, and then apply it to Mars, where it's a longer way from home and we have to move other stuff. And so I think that parallelism is important. And with the ExoMars rover in 2020 going, we hope, a couple of meters, the prospects of understanding deeper how to do these things will happen. And plus, on the Mars 20 rover that JPL is developing, we have the RIMFAX ground picturing radar,

which in one of its modes can see perhaps 100 meters deep. And that's the transition where the engineers need the boundary conditions to know how they're going to drill in this stuff. I mean, it's a civil engineering problem, not so much a science problem. And that's where our creative engineers that always astound me, they figured out how to do MOLA, you know, and this radar are really the connecting glue to that direct hands-on evidence that Chris and team need to validate potential microbial signatures. Chris, you've been wanting to send a drill up there with a good lab to detect biology or at least past biology for a long time, right? That's right.

I want a sample. These exploratory methods like the radar and the molar interpretation are great. They tell us where to go, but ultimately we got to drill down and get a sample to do the biological investigations that I'm interested in. So this is step one, but we need to contemplate how we do steps two and three. Well, Matt, I would suggest one interesting Mother Nature experiment that applies to what Chris just said. And Chris, correct me if I'm wrong, but we have these impact events on Mars that have identified 100-meter-class craters with icy floors, lots of great publications by the community on them. them, those exposures of presumably water ice or salty water ice may provide ephemeral wet zones, if you will, where the water is transitional between its liquid and solid and sublime state. And they may offer prospects, as they occur, of rapid access for the kind of experiments in a

shallower sense that Chris wants to do in deep. Being able to respond to those phenomena produced by the action of Mother Nature on Mars to get at some of the questions, you know, to me would be phenomenal. And those wet zones, five, six meters deep, would show up literally spectacularly in the kinds of imaging radars that are now being used in Earth orbit that will be used to map earthquake zones by NASA with India in the 20s, applying those to Mars in the ways that many members of the community have thought about, including in Canada, with great depth, would be phenomenal. And that would get us into that upper 10 meter area where access is not as problematic and where if there were wet zones, liquid water zones, oh my god, I mean, people like

Chris, correct me, Chris, would be able to literally get that hands-on evidence. Yeah, all of the above, Jim. That's what I would say. We'd like to get samples from all of the above. Our understanding of life, of course, is based on only one data point on Earth. And so when we're searching for life on another planet, we should look everywhere we can possibly look. So the surface, the near surface, the deep aquifers everywhere. we look. So the surface, the near surface, the deep aquifers everywhere. But these subglacial lakes are particularly exciting because we can point to places in Antarctica where we see similar phenomenon, and they are good places to search for life. So yeah, everywhere we can look, we should

look, and let's get down that, get a deep drill down that, into that ice. Chris, I got to ask, and this is really deep astrobiology now, no pun intended, maybe, based on what we know and what might you expect to find down there in that salty lake? If it is a lake and if it's salty and it's salty with sodium chloride, normal salt, then I think our best model for that are these systems that we find in Antarctica where we have saturated salt under ice. And there's two systems that come to mind. One is called Blood Falls. It's a pocket of salty water inside of a big glacier. And the other is in Lake Vita, which is a frozen lake, ice-sealed lake, with a deep salt layer underneath it. And in both cases, inside those salty environments, salty liquid water environments,

we find organisms, microorganisms. We don't find any multicellular life forms or plant life, just bacteria and archaea. And that's what we'd expect to find in the most optimistic case on Mars in these layers of water, if we could get a sample from them. Guys, let me close with this. You have seen the enormous public and political support for going to Europa, sampling from above there, but also landing on Europa has a pretty amazing level of support in Congress. Would you hope that this kind of find, much closer to home on the red planet,

would maybe be generating similar support to do further exploration there at the South Pole of Mars? Matt, this is Jim. I just would like to make one comment before Chris talks about the astrobiology, which is, as a member of the Europa Lander science definition team, a co-chair, drawing the parallels to some of the examples Chris gave as the basis for how we would look at subcrustal ocean exposure in searching for life on a short-lived landed mission, was very strong. And the idea that Mars could contribute to that basis of approach and thought for the Europa Lander mission, which many of us are excited about as a future calling, is a wonderful connection in this understanding ocean worlds or even ancient icy ocean worlds as we move beyond Earth. So I think there is that connectivity. And Mars is a heck of a lot more accessible with lots more data to guide how and where and what we do next than this wonderful,

unexplored frontier of Europa. So connecting those dots to me is a very exciting part of our bigger strategy at NASA in planetary exploration. Just one guy's opinion. at NASA in planetary exploration. Just one guy's opinion. Yeah, I think Jim's got it right on that. I would just add one footnote, which is in all cases, it looks like we need to drill. On Europa, it'd be nice to be able to drill. The deeper we can drill, the better. I keep coming back to drill rigs and the need to be able to drill deeply. And on Europa, unlike Mars, I think there's no option but to do it robotically. So we need to really figure out how do we get through a lot of

ice to the water below it that's so interesting on Mars and on Europa as well and maybe other places. Chris, because I know that you're familiar with the work by Honeybee Robotics on what they call planetary deep drill, which we've talked about on this show. Planetary Society has provided some support for that project. Yes, putting humans there probably make it a little bit easier to handle this drilling. But is that a sign that there may be robotic technology which could maybe not go down a kilometer and a half, but take us down the 10 or 20 kilometers, excuse me, 10 or 20 meters that Jim has talked about. I think that's a good point,

Matt, and they should be able to get to 10 or 20 meters fairly soon. And in principle, I don't see why you can't drill down kilometers robotically as well. We just need to work on it. On Earth, we do it with humans because, frankly, it's easier and cheaper. It's easier and cheaper to send five men and women down as a team to drill in Antarctica than it is to develop a sophisticated robotic system to do it. But on Europa, we're not going to have any choice. We're going to have to do it robotically. On Mars, well, there's a choice to send humans, but it's a very difficult and expensive choice.

On Mars, well, there's a choice to send humans, but it's a very difficult and expensive choice. So my challenge to the engineers at Honeybee and elsewhere is drill deep, drill deep. And we're now finding important scientific drivers to motivate that deep drilling. Let's see if we can do it. My experience, and Jim was mentioning this earlier, once the engineers have a clearly defined goal, they're amazing at being able to get it to achieve it and test it and then implement it. So I hope to see the day when robotic drilling systems can get kilometers deep on Earth and on Europa. Jim, you can have the last word. And Matt, I would just add one thing. Let's not forget the one benefit that we can put humans and robots together at both here on Earth, of course, but also on the moon. Validating the

handoff between human robotics with a driver at the moon as we commit to going back to learn to live with it and learn from it could provide an opportunity to optimize what we need to do on Mars. And so a kilometer and a half, I've been a kilometer and a half drilling experiment in the desert of Kazakhstan with Soviet scientists and phenomenal one and a half kilometers and big fresh impact crater, boy, I relished it. But it took a team of folks to do that. And I can imagine how learning to do that with more robotics and less people could be done, particularly if there's infrastructure at the moon, where there are also problems with the stratigraphy at depth that could motivate that. Not so much astrobiological,

though, as Chris knows. So there may be multiple pathways to get those engineers to do their magic, ultimately on Mars and Europa, but initially close to home and even on the moon. Gentlemen, I knew that this would be a great conversation. You have gone beyond my expectations. Thank you so much for joining us to talk about this tremendous discovery, I'll go ahead and call it that, at the South Pole of Mars. And I look forward to continuing the conversation in the future. Add Ares, guys.

Thanks, Matt. It was a lot of fun. And thanks, Jim, for getting online. And we'll hopefully talk to you guys some other time. Yeah, thanks, Chris and Matt. And, you know, I think the catchphrase is drill, baby, drill. And we're ready for that on Mars and anywhere we can do it. So thanks for having us, Matt.

And thanks for being there, Chris. Jim Garvin is chief scientist at NASA's Goddard Space Flight Center, where he's worked for 34 years. Garvin was twice awarded NASA Outstanding Leadership Medals for his work on the science strategy behind NASA's Mars Exploration Program. He served as NASA's chief scientist and before that as the agency's chief scientist for Mars exploration. Chris McKay is a senior scientist at NASA Ames Research Center and a founder of the Mars Underground that we've talked about on this show. You'll frequently find him in those forlorn places on Earth that most resemble the Red Planet.

He's also been principal investigator for the proposed Icebreaker Life Mars mission that would look for direct evidence of life or past life under the surface of Mars. He too has received a slew of medals from NASA and others. Stick around, we're going to talk with Bruce Betts now, this week's edition of What's Up. Time for What's Up on Planetary Radio. Bruce Betts is, we actually use a tool called Zencaster to record this stuff now. But regardless, he's not sitting across from me as I hoped he would be for this show. But it's still good to talk to you. Hi.

Hi. Here is a comment from Jack Shropshire in Rancho Cucamonga, California. He says, hi, Matt and Bruce. Bruce, we need some more orderly space myths from your mirror universe counterpart. Have you heard from E-Curb lately? Thankfully not. My evil twin that you can find in some random space fact videos.

Yeah. I can try to impersonate him though. Murderly space myths. You and James T. Kirk, you have these, these evil twins from the, probably the same universe,

alternate universe. I wonder if they know each other. We'll try to figure that out. Well, by the time most people hear this, most of the big time fun in the sky will be over. But there's still lots to look at, right? Well, the first statement's not true. The second statement's true. Is it really over?

I mean, yes. Mars' closest opposition is the 27th, was the 27th, and closest approach is July 31st. But Mars stays nearly as bright for many days and even weeks. It stays very, very bright. So don't give up on it. In fact, you can check out Mars in the early evening, and it's rising even earlier. So it should be up after sunset in the early evening east. And then as you sweep your eyes across the sky, you can see yellowish Saturn, bright Jupiter, and super bright Venus over in the west in the early evening. And for you, Matt, I've arranged something. Well, okay, it happens every year. But the Perseid meteor shower, traditionally the second best meteor shower of the year, with 60 to 100 meteors per hour from

a dark site around its peak. And its peak is August 12th, the night of like the 12th and 13th of August. But there's increased activity several days before and after. And here's the really good news. Moonlight, not an issue this year around the peak because it will be new moon. So it's a great time to go out and see Perseid meteor shower, August 12th, 13th peak, but happening for several days before and after. That's great. I'll miss it by a little bit because I will be at a dark site actually watching a Pluto occultation. And that'll be something we talk about on the show in a few weeks, but it'll be on the evening of the 14th. Sounds like there might still be a little bit of a light show. Oh, yeah.

Perseids have a relatively broad peak. You should be looking. Excellent. Thanks. What else you got? I got this week in space history. 2007, Phoenix mission launched to Mars. Launched along with it the Visions Mars DVD from the Planetary Society

that contained science fiction art and literature and greetings, including one that our own Merk Boyan has turned into a video from Carl Sagan to future explorers. It is a beautiful thing. It is a work of art. And we will put up the link at planetary.org slash radio on this week's show page. People will love listening to it and seeing what Merck has done with it. In 2011, Juno launched, of course, still doing great stuff at Jupiter. And 2012, the Curiosity rover landed on Mars. I'm still getting over the fact that it's been 10 years since Phoenix landed on Mars.

Yes, sorry. But it's been more like four or five years in Mars time. That's true. Does that make you feel better, Mars years? Much, yeah. Work on Mars years. We're all younger. All right, we move on to early space.

Oh, wait, no, that's the wrong one. Random space fact. I think I do want to get Ecururb to record one of those for us sometime. Check with my communications with other dimensions, and we'll see what we can do. In the meantime, 1758, as you probably remember, Matt. Very well. Yeah, Charles Messier was trying to find Halley's Comet, which was predicted to be coming back into the sky. Instead, he found a fuzzy patch that didn't move. It was later named the Crab Nebula.

This is when he decided he should catalog permanent fuzzy-looking things in the sky so he and others wouldn't confuse them with comets. Hence, the Messier Catalog was born, which is still used today as a list of good things to look at, particularly in amateur telescopes like Nebula and Nebulae and galaxies and star clusters. And the crab Nebula became M1. I remember telling Charlie, Charlie, you're going to be remembered forever for this. I'm sure he had no idea until he pointed it out to him. All right, we move on to the trivia contest.

I asked you, after Apollo 11, what was the next U.org. And I am really delighted because Laura Dodd, who is a longtime listener and longtime entrant in the contest, she has never won as far as I know. Laura Dodd of Eureka, California said, STS-26, Space Transportation System Mission 26, was the second NASA spaceflight with an all-space veteran crew. Five astronauts, significant for being the first shuttle flight after the Challenger disaster, correct? Well, except for the statement that it was the second all-veteran crew. They're actually Apollo 10, as well as, of course, some of the earlier Gemini flights. And all veteran, well, I don't know about Gemini, but Apollo 10 had all veteran.

Anyway, I'm getting distracted. The basic gist of it was quite correct. It was the return to flight mission after the Challenger disaster. They wanted all veterans. Congratulations, Laura. It's about time. You're going to get a nice planetary radio T-shirt, better than nice, and a 200-point itelescope.net astronomy account,

which we'll talk about because that's going to be the prize package for next time as well. She added, continuing to learn or remember so many things from your trivia questions. Thank you for the brain treats, Dr. Betts. Oh, you're welcome. Tasty and so good for you. Michael Thompson, Redondo Beach, California. A lot of Californians. He says, while it intuitively makes sense that the all-veteran crew would be selected for the return to flight, this crew is actually originally assembled for the dangerous first use of the Centaur-G payload booster that would have been on STS-61F.

And then they decided after Challenger that they would never use that big dangerous rocket that was designed to go on the shuttle payload bay, right? Interesting. Yes, correct. Mark Little, we hear from him all the time in Northern Ireland, says the pilot of the mission was Richard Covey, I think, who went on to jointly lead the commission investigating the Columbia disaster with Air Force Lieutenant General Thomas Patton Stafford, Tom Stafford. Finally, from Hudson Ansley in Bloomfield, New Jersey, he mentions this reminded him of where he

was when he heard about the loss of Challenger. And I remember where I was too. It was a horrible, horrible day. Do you remember where you were, Bruce? Yes, I do. Well, no need to go into detail, but it was just one of those things that you never forget. On that note, please take us to a new contest. Well, Matt kind of harassed me because there were fewer entrants, so we wanted something easy. Here it is. What, pretty much no matter how you measure it, what is the most abundant chemical element in the universe? Go to planetary.org slash radio contest. It's not obvious if you don't know it, but it's not hard.

Now, I couldn't run for you. I can start asking questions about your personal life. It's too easy. No, it's fine. It's fine. I like it a lot. Not good enough for you? I can start asking questions about your personal life. Tuesday the 8th at 8 a.m. Pacific time. And the winner of this one will get another Planetary Radio t-shirt that you can take a look at and admire the model at chopshopstore.com. That's where the Planetary Society store is. And a 200-point itelescope.net account. At itelescope, they have that brand-new planning tool that makes it even easier to use their worldwide network of telescopes.

200-point account. That's all I have to say. All right, everybody, go out there, look up the night sky, and think about if you could design a constellation, move the stars around, what would your constellation look like? Thank you, and good night. I'm just trying to think what we would call it if it was you and me with microphones doing this. Maybe we should make the, we'll make that a contest sometime. What would be the name of the constellation with Bruce and Matt? Gemini has already been taken. That's Bruce Betts. Because we're twinsies. He's the chief scientist for the Planetary Society, and he joins me every

week for What's Up. Planetary Radio is produced by the Planetary Society in and he joins me every week for What's Up. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its deep-thinking members around the world. Mary Liz Bender is our associate producer. Josh Doyle composed our theme, which was arranged and performed by Peter Schlosser. I'm Matt Kaplan. Add Ares.