Planetary Radio: Space Exploration, Astronomy and Science - Looking for Life with Chris McKay

Episode Date: April 10, 2006

Planetary scientist Chris McKay talks about where and how we should look for life in the universe, including Europa and Mars.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Transcription by CastingWords Frontier. I'm Matt Kaplan. He explores Antarctica, he explores Mars, and he'd like to explore Jupiter's moon, Europa. Chris McKay's quest is to find a second Genesis, another place in the universe where life found a home. We'll talk with him about that search and why he's now also involved with plans to explore a place where no one in their right mind expects to find life, the moon. And later today, we'll ask, with apologies to the bard, what's in a name? A spot by any other spells a treat for listeners. As we pick the winner of our Name That New Spot on Jupiter contest, Bruce Betts will

join us in transit with his what's up news about the night sky and much more. News, aye, there's the rub. As we prepare this week's show, the European Space Agency is just hours from orbital insertion of its Venus Express probe. Our own Emily Lakdawalla is in Darmstadt, Germany, where she'll be covering this event. Keep an eye on her blog at planetary.org. Which happens to be where you can get a glimpse of beautiful pictures snapped by another new orbiter. The Mars Reconnaissance Orbiter is still in its shakedown period

as it settles into its permanent home over the red planet. The images it is returning are already some of the best ever taken, and NASA says we ain't seen nothing yet. Some of these shots from the HiRISE camera are truly humongous, as much as 40 megabytes each. And here's a This Week in Space history item Bruce won't have time to mention. Do you remember April 12, 1981? NASA does. That was the day Commander John Young and pilot Robert Crippen rode Shuttle Columbia into orbit. and pilot Robert Crippen rode Shuttle Columbia into orbit.

It was Space Transportation System 1, the very first full-fledged flight by the space shuttle, and it was a rousing success. The space agency is celebrating all of this week with special events, including several appearances by Young and Crippen and even the unveiling of a shuttle sculpture. Millions of comets, but are they all homegrown? That's a question for Emily. I'll be right back with Chris McKay.

Hi, I'm Emily Lakdawalla with questions and answers. A listener asked, We know from the metal composition of our solar system that the sun is at least a second or third generation star. Does that mean that some of the comets or Kuiper belt objects could have formed from the Sun's predecessor stars? There is ample evidence to suggest that the ingredients that formed our solar system came from previous generations of stars. It takes a giant star to fuse hydrogen and helium nuclei into heavier elements that astronomers call metals. One or two generations of giant stars must have formed, lived full lives, and exploded as novae,

their metals scattered throughout the galaxy, giving our solar system lots of heavier elements like carbon, oxygen, iron, and magnesium. Scientists who collect space dust from the upper atmosphere or through missions like Genesis and Stardust who collect space dust from the upper atmosphere, or through missions like Genesis and Stardust, have identified microscopic dust grains that have isotopic compositions that just don't match our own suns, meaning that these dust grains very likely formed in some other star system. The ingredients are everywhere, but could anything larger than dust in our solar system be a castaway from an exploded star? Stay tuned to Planetary Radio to find out.

His home is near NASA's Ames Research Center in Northern California. But planetary scientist Chris McKay can be found pretty much anywhere, including some of the wildest spots on Earth. So it was a bit ironic to sit down with him at Ames to talk about where and how we should look for life in the universe, beginning with what could be lurking under the ice on Jupiter's moon, Europa. Chris was about to speak at the recent Europa event, co-sponsored by the Planetary Society and NASA's Astrobiology Institute, to which he's a major contributor. Chris was also recently named program scientist for the robotic lunar exploration program planned by NASA

and is on the development team for a new and very ambitious rover that will head for Mars in 2009. Chris McKay, welcome back to Planetary Radio. First of all, this may be the first time we don't devote the whole conversation to Mars, but we've got to talk a little bit about the red planet. Okay, we will, but let's start on Europa. Let's do that, since we're at your home base, really, the Ames Research Center. We are here because the Planetary Society is co-sponsoring this Europa event, talking about what we might find there if we go

and why that's a really good reason to go. Precisely. And the thing that interests me about Europa, of course, is the possibility that we might find their life. And when I say life, I mean a particular thing. I mean life different from life here on Earth. One of the things we've learned from the investigation of life on Earth is that all life on this planet shares a common biological and biochemical heritage.

It's all the same stuff. That's an interesting result. But it means that if we want to find another way, we need to look beyond the Earth. So when we look at Europa and Mars and other places, what we're looking for really are aliens, something that's alive but different, that represents a separate alternate origin of life, what I call a second genesis. That's what we hope to find on Europa. Where might we find it?

Well, the ocean below the ice is the obvious candidate. But there's a lot of ice on Europa. It's going to be very hard to drill through that ice and get a sample of that ocean. it's going to be very hard to drill through that ice and get a sample of that ocean. In fact, that might be way beyond what we can do even in the next 20, 30, 40 years. But fortunately, it may be that nature brings the samples for us. We see on Europa these features that look like cracks. If they are cracks and there's an ocean underneath that ice,

the water from that ocean is coming up to the surface and being deposited on the ice. If there's life in that water, that life is now being left on the surface. So as some people call it, frozen fish right there on the surface of Europa. Well, it may be that all we have to do is land on the surface of Europa and scrape the stuff off one of these cracks, surface cracks, and analyze it. I think that that could be very exciting. We could do that in situ. We could do that right on Europa.

Or, and more powerfully, we could collect some of that stuff and bring it back to Earth and analyze it here. You were talking about a mission that would sort of be a combination of deep impact and stardust. Exactly. You might imagine a mission that flies out to Europa and, like deep impact, smashes an object onto the surface, kicks up a cloud, and then, like stardust, moves through that cloud and collects the pieces and brings it all back to Earth. We might have in such a mission organic material

that would be the remnants of the biology in the ocean below the ice on Europa. And I found as I searched that wonderful tool, the Internet, that this is something that you've been thinking about for quite a while because you and a pretty distinguished team way back in 1997 proposed a discovery mission that you call the Europa Ice Clipper. Exactly, and Ice Clipper was to do just that. It was to impact the surface of Europa and then use a Stardust-designed spacecraft to collect the dust that was kicked up. 1997 Stardust was just being designed.

It's now returned to Earth successfully, so the mission is in a much stronger place than when we first proposed it. I think we're going to come back with this idea, Ice Clipper, one more time and see if the success of Deep Impact, the success of Stardust, makes it a little more credible to imagine doing this on Europa. So really no technological barriers to making a mission like this work, even though it would still be a first. It would be difficult.

The hardest part is combining the impact and the collector. Deep impact made an impact but then didn't need to go into it. And Stardust moved through a comet where the tail was already being generated by the comet. Here we're proposing to choreograph the mission in such a way that we do both. So we make an impact and then fly through that impact. So we make an impact and then fly through that impact. If we come in too low or too high, we might collect too much material and crash or not collect enough. So it is a little trickier, but it's a logical step forward given what we already know how to do. So it's a challenge, but I think it's a challenge that we ought to start looking at seriously.

And if we get a piece of Europa, we bring it back to Earth and find, indeed, that there is evidence of life in this material, and that that ice and that organic material is biological but alien, a different type of life, even if that life is dead in the sample that we get, it would be very exciting. It would be our first scientific evidence of not just life beyond the Earth, but a different alternative life beyond the Earth. So on the spectrum of science that you would like to see conducted around our solar system, this is up there. Well, for me, it's number one.

To me, this is the most interesting science question that remains. Science has answered a lot of the simple, everyday, what I call kindergarten questions. Why does the sun shine? Why is the sky blue? How many planets are there? Although we're still debating that, aren't we? But when you ask the question, is there life out there? We don't have any scientific evidence that addresses that question. And if we could find evidence of alien life, a second genesis on Europa or Mars, we would have the first scientific piece of the puzzle. And that would be terribly exciting.

And that would be my number one goal for solar system exploration. So perhaps your number one goal, but certainly not your only focus. You do look at a lot of the solar system. And we're going to get to Mars, of course. You can't talk to Chris McKay without talking about Mars. But you've been looking at the moon lately, considerably closer to home. Yeah, and you might wonder, what does the moon have to do with search for life? Well, indirectly, it does. The moon is how we're going to get to Mars. Mars is the most interesting target, in my opinion, from the point of view of a search for life, search for a second Genesis.

Europa is a good target. Mars is an even better one. Mars is such a big target, so much area to cover, so many places to drill, so many mountains to climb, that I think it's a challenge that's worthy of human exploration. And so I'm an advocate for that reason and for others, for human exploration of Mars. Well, NASA, the engineers at NASA and NASA collectively think that the best way to send humans to Mars is to first send them back to the moon, build up that capability on the moon. So I take the view that, okay, if we're going to go to the moon, let's go to the moon. Let's do that.

Let's learn how to do it. But let's keep our eye on the long-term goal, which is Mars and the search for life on Mars and human exploration of Mars. So I've been involved in the Moon program partly to help it get us to Mars and to help us do it as quickly and as efficiently as we can so that we learn what we need to do to go on to the target that really interests me, which is Mars exploration. Back with more from Chris McKay in just a minute.

This is Buzz Aldrin. When I walked on the moon, I knew it was just the beginning of humankind's great adventure in the solar system. That's why I'm a member of the Planetary Society, the world's largest space interest group. The Planetary Society is helping to explore Mars.

We're tracking near-Earth asteroids and comets. We sponsor the search for life on other worlds, and we're building the first-ever solar sail. We didn't just build it. We attempted to put that first solar sail in orbit, and we're going to try again. You can read about all our exciting projects and get the latest space exploration news in-depth

at the Society's exciting and informative website, planetary.org. You can also preview our full-color magazine, The Planetary Report. It's just one of our many member benefits. Want to learn more? Call us at 1-877-PLANETS. That's toll-free, 1-877-752-6387. The Planetary Society, exploring new worlds. Society, exploring new worlds.

Welcome back to Planetary Radio and our guest, planetary scientist Chris McKay. Chris was recently named program scientist for NASA's plan to send robotic spacecraft to the moon in preparation for the return of humans. The space agency also wants these missions to conduct scientific research on Earth's satellite.

But there are other people who have said that they see the moon, at least in terms of science, as a distraction. Well, the moon could be viewed as a distraction, but in a sense, it's an interesting distraction. There's people who think the moon is interesting. The other planets, Venus and Mercury, could also be viewed as distractions if your sole goal was to get to Mars. But I think there's room for diversity in the program, and I think the moon has enough science to be an interesting object in its own right. It's a planet that only a geologist could love, really. But still, there are geologists who could happily spend many decades studying the moon.

I equate it in level of importance with, say, the Antarctic. We have a program of human exploration of the Antarctic that's been continuously going for 50 years. It's not a big item in the budget, but it's a persistent item. You can imagine a program like that on the moon where we have a continuous base, humans are there all the time doing scientific exploration, geology in this case, and it might be a base that operates for 50 years just like the Antarctic. I could see that there's enough science on the moon to make it as interesting as the Antarctic. Mars I put in a completely different category, but the moon is not without interest still. All right. Mars. We found the water.

Yeah, well, you know, we didn't really find the water. We found where the water was. We still have not actually found any liquid water on Mars yet. And that still remains a challenge. But I give you the point. We found the traces of the water. We're pretty convinced that this was a planet that was wet, and it was wet all over. Now, what do we do next?

We found the water. What do we do next? Well, we now have to start looking for the organic material. The correlates of life on Earth are water and organic material. Life is made of organic material, and it lives in water. Well, now that we've found the water on Mars, we need to start seriously looking for the organic material, and that's where we might find the remnants of biological material,

the remnants of a Martian organism, and the ability to determine whether it really is related to us or a separate second genesis. I wouldn't want to express in any way that the Viking missions, as exciting and wonderful as they were, somehow got something wrong. They didn't. They told us so much about that planet. And one of the things they told us is that the way they were looking for life was the wrong way to look.

Yeah. Viking went to look for life on Mars based on the notion that we could make things grow. And that presupposes two things. One, it presupposes that what you're looking for is alive. You want to make it grow, it's alive. And second, that you know what it likes to eat. And we now realize on Earth that many organisms that live in the soil, we can't get to grow in culture because we don't know what they like to eat and the conditions under which they like to eat.

So it's not an ideal way to search for organisms in the soil. The second thing we now know about Mars is that if there's life on Mars, for the most part, it's now dead. In fact, it might be dead everywhere. And so maybe we ought to be looking for the remains of life rather than something that's actually alive. And I've been focusing on the polar regions of Mars, where in the ice, frozen in the ground, we might find dead but preserved frozen Martian microorganisms. These would not be fossils.

These would be actual corpses, if you will, microscopic Martian corpses. But we'd be able to look at their organic material, look at their genetics, if they have genetics, look at their amino acids, determine how they relate to our life. So we, indeed, Viking was a major accomplishment, but one of its lessons was when we go back to Mars to search for signs of life, we will do it in a different way than Viking did it. In a sense, I'm turning away from science with this next question because, of course, we don't have much information about life anywhere else. In fact, we have none, but we've got a lot here, and you are one of those who has found life in just about every possible environment

that exists on this planet, where these extremophiles that you've studied have found their niche and made a success of it. Where do you stand on the philosophy that perhaps life is as natural an occurrence, that it is as natural a part of the evolution of the universe as mountains? It's a good question. Is life a natural occurrence, a commonplace occurrence in the universe, or is it a rare, maybe even singular event? Scientifically, we have no data to answer that question, but obviously I have an intuition that life is a commonplace occurrence.

Otherwise, I wouldn't be spending my time searching for it. So I am testing hypothesis, and my hypothesis, my working hypothesis, is that life is a naturally emerging phenomenon given the right conditions. We don't know exactly what the right conditions are, but we know that at least on Earth, the right conditions were met. So if we search for other planets that have those conditions and the hypothesis of life being natural is correct, we should expect to find life. It may be that other conditions also, not like Earth, also create life. We're not prepared to search for that yet because we don't even know what those could be. So we'll start searching for life like us,

but I hope someday we'll be in a position to find life that's not like us, really different, maybe not even based on water or carbon. But I want to emphasize that the scientific method forces us to treat the data and to treat the problem scientifically. We have our hopes. We have our desires. I would like the universe to be full of life. But I'm prepared for either answer.

It is or it isn't. The question is one that has to be addressed empirically, not just based on what we would like to be the case. So I can hardly wait for the answer. Spoken like a good scientist. Chris, thanks so much for joining us. Okay. And you're going to be speaking in just a few minutes here about Europa.

Yep, back to Europa and maybe one of the places in our solar system where we'll get our first data point about life, life not as we know it. We'll look forward to having you back on the show sometime soon. Thanks, Matt. Chris McKay is a planetary scientist with the Space Science Division of NASA Ames Research Center and is one of the better-known names as we continue to explore our solar system and beyond. We will explore what's going on in our solar system and beyond with Bruce Batts right after this return visit from Emily. I'm Emily Lakdawalla, back with Q&A.

Could any of the icy bodies in our solar system, the comets and Kuiper belt objects, be interlopers from other stellar systems? It appears to be very unlikely. You need three things to happen. The body must form around another star, be ejected from that star, and then be captured by our star. We do know that plenty of other stars seem to be surrounded by planetary systems, so formation is not a problem. Ejecting an object is also a possible and frequent occurrence. You need to perturb its orbit, which can happen if another star passes close by, or perturb the gravity of the original star through its death. So it's certainly possible that a few scattered icy bodies may wander in the direction of our tiny out-of-the-way solar system. The problem is that when they arrive

here, they don't stick around. Simulations suggest that only about one in every million million interstellar comets that passes within the sun's grasp gets caught. This is such a tiny number that there are probably no Kuiper Belt comets that are captured objects, and probably only a handful of Oort cloud comets. The likelihood of any of these being big enough ever to see from Earth is vanishingly small. To see stuff from other star systems, we're going to have to go there. Got a question about the universe?

Send it to us at planetaryradio at planetary.org. And now here's Matt with more Planetary Radio. Time for What's Up on Planetary Radio. We are ready to talk with the director of projects for the Planetary Society, Bruce Betts. We are ready to talk with the Director of Projects for the Planetary Society, Bruce Betts. He is at LA International Airport, otherwise known as LAX. Oh, man of many projects, where are you headed? I like that you're trying to hide where I am, Matt.

I appreciate that. I'm actually at Burbank Airport. Oh, I'm sorry. But I am a, yes, man of many flights and many airports in Southern California. I am headed off to Massachusetts for the dedication and opening of the Planetary Society Optical SETI Telescope, the world's first dedicated optical SETI telescope, as you heard about it if you listened to the show with Paul Horowitz and Andrew Howard. That should be a lot of fun. I wish I was coming along for the ride. It's too bad we're not sitting across from each other because we're going to have that special contest, all those attempts to give a name to that new spot.

But that's coming up later. What else do you have for us? Well, we've got our planets in the night sky. Don't miss Mars as it gets a little softer and fainter and hanging out with all Deborah on its star companion. Nothing like each other but looking kind of similar in the evening sky towards the west, looking reddish. We've got Saturn in the evening sky, yellowish, and hanging out between Gemini and Leo, kind of follow Castor and Pollux, the bright stars, you'll find yellowish Saturn. And in the pre-dawn, oh, we also have Jupiter hanging out now in the evening sky, but rising in the 8, 30, or 9 kind of time frame in the east, so anytime in the late evening you'll see a very bright star-like object, that's Jupiter. And in the evening sky, but rising in the 8, 30, or 9 kind of time frame in the east. So anytime in the late evening, you'll see a very bright star-like object.

That's Jupiter. And in the pre-dawn sky, we've got Venus looking outrageously bright as usual, high in the east right before dawn. We move on to random space facts. The Optical SETI telescope, you may have heard this, but I think these are worth repeating. The Optical SETI telescope, you may have heard this, but I think these are worth repeating. Even if you have, they will be processing 3.5 terabits of data every second. That's the equivalent of every book in print every second, looking for nanosecond pulses. We also will have the largest primary mirror on a telescope-like object east of the Mississippi or

Texas or however you want to define it at 72 inches. By the way, did anybody look at you when you said random space fact? They did a bit. Yes, they did. Certain officials seem to have taken a greater interest in me now. You wave to the TSA people for us.

Hi. It's radio. It's okay. So, shall we move on to trivia contest, Lance? Yeah, TSA people for us. Hi. It's radio. It's okay. So, shall we move on to trivia contest, Lance? Yeah. Are you ready for this? Go ahead and remind people what we asked. All right.

We asked, what should the name of the new red spot on Jupiter be? There's a red spot. Basically, a white oval is converted to a red spot and changed its party affiliation in the recent weeks and months. And so there's a second smaller red spot on Jupiter. We asked you what should it be called and swore to base our answer on what we thought was the funniest. So how did we do, Matt? People struggled with this.

We got a lot of entries, and of course we will not have time to read all of them. We apologize for that, but we appreciate every one of them. The dominant theme, not the exclusive, but the dominant theme seemed to be adolescent skin problems. Really? Yeah, we got a lot of mention of pimples and things. So we brought the best out of our listeners, is what you're saying. Basically,

yeah. I mean, you know, I'll give you one example of those, and it's from Torsten Zimmer, a regular, and he mainly gets mentioned for this, not for the name but for all the stuff he wrapped around it. Here it is. It's very obvious what's currently happening on Jupiter. The planet has now reached the first stage of puberty.

Since the new feature certainly will not be the last of its kind, we should name it Pimple 2. Future missions to Jupiter should look out for other signs of planetary puberty, evidence of ring enlargement, higher levels of atmospheric testosterone, increasing, here's my favorite, increasing interest in surrounding moons, or emergence of body hair. We'll just leave it at that. Well, okay. Thank you, Torsten.

Listen, Stephen Witte outdid everybody. He came up with 25 different names, one of them a bucket full of marmots, but he does point out that that's been used. If you've been with the show long enough, you know. I kind of like this one, Bruce. His nominee is Bruce. Well, that clearly should win. But that it should be done with an Australian accent like Monty Python.

Well, that clearly should win. But that it should be done with an Australian accent like Monty Python. From Greg Winkler, diminutive intrajovian pseudo-Crimson southern hemispheric tempest, which is an acronym that we won't pronounce. But thanks anyway, Greg. This was kind of cute. From Nicole Long, see spot run, run spot run. I also enjoyed that one. A little tough in the science publications.

We've made further observations of see spot run, run spot run. It's hard to get any respect, as opposed to our winner, which would get people an enormous amount of respect. Go ahead, Matt. Here it is, as chosen by the official judges for the contest today, that is Bruce and me, from Jeremy Strozer, Ant Flo. Ant Flo.

F-L-O-W, Ant Flo. Why? We don't know, but we just like it. We just like it. Ant Flo. It made us laugh. And so it will be duly submitted to the IAU? Exactly. I'm sure they'll be happy to accept. Amplow is the new official designation. Well, you see, it's the F-L-O-W that makes it so scientific.

We're going to get a... We're reporting my observations of Amplow in the literature. We're going to get an Explorer's Guide to Mars poster out to Jeremy in Arlington, Virginia. Thank you, all of you, once again, for entering. Bruce, we're almost out of time. Can we go on to the next contestant? And you know what? We've got people saying we should go back to giving away T-shirts. Can we do that?

Let's do it. All right, then. And then a Planetary Radio T-shirt to the person who gets this question from Bruce correct and happens to be the one that we randomly choose. Take it, Bruce. Here's one. After taxing your brain for our humor contest, I'll give you something a little easier this time around.

What is the name of Saturn's moon that is really bright on one side and really dark on the other? So Saturn's moon has a very high albedo contrast. Go to planetary.org slash radio. Find out how to email us your answer and try to win a glorious Planetary Radio t-shirt. When do they need to get that in by, Matt? By April 17 at 2 p.m. Pacific time. We're done. And you've got a

plane to catch. I do. There's some kind of announcement I'm missing even as we speak. All right, everybody, go out there, look up at the night sky and think about why planes fly. And hope they keep doing that. Take care, man. You too, and say hi to Ant Flo while you're back there.

I will. We'll see if we can see Ant Flo through the telescope. Oh, maybe not because it's a light bucket. I don't know if we'll be able to get Ant Flo into the light bucket. Bruce Betts is the director of projects for the Planetary Society. He's here every week, or he's somewhere every week, for What's Up. Big discoveries at Saturn, and we'll talk about them next week with Cassini mission scientist Linda Spilker. Planetary Radio is produced by the Planetary Society in Pasadena, California.

Have a great week, everyone. Thank you.