Planetary Radio: Space Exploration, Astronomy and Science - Alan Stern: Organics on Pluto and Fairy Castles on the Moon

Episode Date: February 27, 2012

Alan Stern: Organics on Pluto and Fairy Castles on the MoonLearn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Organics on Pluto and fairy castles on the moon, this week on Planetary Radio. Welcome to the travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. We heard from Alan Stern last week, and the head of the New Horizons mission to Pluto is back with more. He'll share news about that distant world, but he also has some revelations about our own moon. Bill Nye has more to say about NASA's new budget, and Bruce Betts will take us up into a particularly fascinating night sky.

Have you seen Snapshots from Space? The second episode of our new video series with Emily Lakdawalla is on YouTube. Here's the Planetary Society's Science and Technology Coordinator to tell us more. But first, we'll visit yet another moon. Emily, welcome back. Tell us about this February 22nd entry in the blog, which begins with this really pretty stunning image of Iapetus. Yeah, Iapetus is one of the most distinctive moons in the solar system. It's pretty large, actually.

It's the third largest moon of Saturn. And it has this walnut shape. It's got a high ridge running almost all the way around its equator, which is very strange. There are ridges on other moons, but Iapetus only has one of them, and it's exactly on the equator. So it looks very strange. I'm glad you made that walnut analogy, because that's the first thing I thought, and I've never had that impression until I saw this image, this incredible image that you've got at the top of the entry. And of course, it begs the question, how did it get one single ridge that's aligned exactly to the equator? And a lot of people have published ideas about this. There have actually

been, I think, six or seven different groups trying to figure out what made this ridge. And this is the first paper I've read that not only explains how the ridge formed, or at least comes up with a plausible explanation, but also explains why it's only seen on Iapetus and we haven't seen anything like this on any other moon. So I don't know if you can capture this in a couple of sentences, but what have these guys proposed? Their explanation is actually really cool because it involves Iapetus having its own moon at some time in the past. And the way that that works is that Iapetus is very far from Saturn. So it actually has a fairly large region over which it's gravitationally dominant. You know, it's not the biggest moon in the solar system, but other

large moons tend to be closer to their planets. So they wouldn't have any hope of having their own ring system or moon. But Iapetus is far enough away, and it's big enough that it could actually once have had its own moon. And if that moon, if its orbit were to decay, then it would get torn apart by Iapetus's tidal forces and would possibly just collapse into this ridge that formed right along the equator. It doesn't really sound, to me, it doesn't sound very plausible, but these guys, they worked through the physics and it actually makes a lot of sense. And the reason why it only happened in Iapetus, not on all these other moons, is because Iapetus is so far away from Saturn that this collapse wouldn't have happened until after the heaviest part of the bombardment of the solar

system with comets and asteroids. So any feature that it formed from this collapsing ring would have formed too late for it to have been destroyed by some other force. And as you talked about that, I've been watching the animation flying along the ridge of this moon of Saturn. We live in amazing times. Something else for people to watch. Give us a little tease for the second edition of Snapshots from Space. Well, actually, this edition of Snapshots from Space starts with a pet peeve of mine, which is people publishing versions of space images of other

planets that are really terrible, that they could do so much better with if they just went back to the modern data. So, I'll show you lots of examples of the familiar images from space that are really kind of terrible, and also lots of examples of what you can do to make them so beautiful. And you'll find that video and lots of other great stuff from Emily in the blog at planetary.org, also on the YouTube channel for the Planetary Society.

Emily, thanks very much. Thank you, Matt. She's the science and technology coordinator for the Planetary Society and a contributing editor to Sky and Telescope magazine, among other things. Let's talk with Bill Nye, the science and planetary guy. Bill, you visited JPL once again last week, and there was a very interesting gathering with a lot of concerned people. Yes, I was invited. I was invited to sit with the Jet Propulsion Lab employees and Congressman Adam Schiff. Now,

Congressman Adam Schiff used to have Jet Propulsion Lab in his district, but he doesn't anymore, but he's still a big advocate of space exploration, especially planetary exploration. I take it this group got together because they share a concern that a lot of people have about NASA's budget. No, no, not at all. Yes, yes, exactly. So what's happened, NASA's budget has been cut, everybody's budget's been cut, world economic crisis, okay. But what's happened maybe by accident is the planetary science budget has been disproportionately reduced. That is to say, science budget has been disproportionately reduced. That is to say, it's been cut more than the other things. And this is inappropriate because not only is it what Jet Propulsion Lab

does, but we will lose our capability. The world will lose our ability to land on other worlds, especially Mars. Entry, descent, and landing capability will be gone forever. If these people go off to get other jobs in software industry, let's say communications industry, other high-tech businesses, they won't be around to keep the thing going when somebody does decide that it's worth looking for life on another world, be it Mars, Enceladus, or Titan. This discovery of living things elsewhere would change everything. For those of you who are Planetary Society members, and of course, spend some time on the planetary.org site, there's quite a nice entry this week by Emily Lactewal about how far our radio signals have gone in about the last century. But we're talking about looking for life right down the solar systemic block, Matt. And as we said last week, there will be much more said about this in the coming weeks and months.

Good to hear that the congressman, even though it's not in his district anymore, is still fighting the good fight. Bill, thank you so much. Oh, thank you, Matt. I mean, he's really fighting the fight. This is his deal, and this is what was discussed with the audience. Well, thank you, Matt. I've got to fly. Bill Nye, the planetary guy. It's his deal, too. He is the chief executive officer of the Planetary Society, and we'll talk to him again next week right after his presentation at the TED conference. There's a tease for you. Here's a bit of a tease for the second part of our conversation with Alan Stern. That's just a few seconds away. Alan Stern is principal investigator for the New Horizons mission, now just 40 months away from Pluto. Last week, he gave us an update on the spacecraft and asked for our help in getting a postage stamp issued in its honor. This time he wants to tell us about research that has made this voyage of discovery even more exciting.

Alan served as NASA's Associate Administrator for the Science Mission Directorate. Now he's back at the Southwest Research Institute in Colorado, where he is Associate Vice President of the Space Science and Engineering Division. Alan, it's rare that we will do a two-parter like this with one guest, but you just have so much going on. Of course, we still want people to go out there and join your campaign at change.org to get that New Horizons stamp. But let's talk a little bit more about the mission and this world itself.

You are the principal investigator for a project that has been conducted on the Hubble Space Telescope that really has made Pluto an even more interesting place, more enticing as New Horizons heads out there. Well, thank you. Well, you know, this wasn't directly a part of the New Horizons project, but I'm a co-investigator on one of the new instruments on Hubble. It's called a cosmic origin spectrograph, spectacularly sensitive new ultraviolet spectrograph. And we discovered, by pointing it at Pluto with this great new tool, we actually discovered a spectral feature in the ultraviolet that tells us that there are very likely to be hydrocarbon or a kind of molecule called nitriles on the surface, both of which are prebiotic precursors of things we look for on Mars.

And there they are all the way on the outer skirts of the solar system lying on the surface of Pluto. Talk about remote sensing. How were you able to use a telescope not far from our planet to find these complex molecules so far away? Well, we just pointed the Hubble at Pluto, put Pluto right down the barrel of the spectrograph, and soaked up the light for as long as they would let us. And took a look at that spectrum, and it's so much more detailed than what we were able to see with older Hubble instruments or even with precursors like the International Ultraviolet Explorer satellite

that, well, it was like taking candy from a baby. So this is stuff up in the ultraviolet. Yeah, absolutely. The story just gets more interesting. First we discover Pluto as an atmosphere, then the atmosphere doubles its pressure, then we see that there's global change. Next thing you know, we're finding two new moons and then yet another, and maybe evidence even coming of more moons and rings. The whole context with the Kuiper Belt and so many small planets that the solar system made in its early days,

this is just going to be a spectacular mission. It's been a long time in the coming, but we feel like This is just going to be a spectacular mission. It's been a long time in the coming, but we feel like we're almost ready to turn final on approach. Two-thirds of the way out there now, and just can't wait for 2015. What is the significance of finding these molecules out there on that very frigid world? Well, it tells us it's a complex place. These kinds of molecules, frankly, they were expected. We went looking. We knew what we were looking for. Pluto's atmosphere, which is mostly made of nitrogen, the same stuff we're breathing right now, also has methane in it. In fact,

methane was the first molecule discovered in Pluto's atmosphere. And there's carbon monoxide. And when you put nitrogen, carbon monoxide, and methane together and illuminate them by the sun, even that far out, chemistry happens. And minor species that are more complex, hydrocarbons and these things called nitriles and others actually get created in the atmosphere, and then they sort of rain out slowly onto the surface. Also, galactic cosmic rays, onto the surface. Also, galactic cosmic rays, just of their own volition, can create the same chemistry in the ices on the surface of Pluto. So for a long time, more than 15 years, theorists and modelers had predicted this kind of chemistry would take place and produce these kinds of molecules on the surface of Pluto. And now we have direct evidence from the cosmic origin spectrograph on Hubble that they're there. And with New Horizons, we hope to actually map their

abundance across the surface. Are you also learning from distance that Pluto is a more dynamic place than maybe a lot of people used to think? It certainly is a dynamic place. I'm not sure, in the scientific community, that's a lot of surprise, but maybe in the public it is. We saw in Pluto's cousin, Triton, which orbits Neptune and which is another planet-sized world. In fact, Triton used to orbit the sun. We saw in the Voyager encounter geysers going off at 30 degrees Kelvin. We saw evidence of seasonal snows and polar caps and many of the same things that we're seeing at Pluto. These dwarf planets are blowing our minds. No one expected worlds this small could have so much activity. And I think when we get to Pluto, about the only thing you can predict is that it's going to be unpredictable. So hold on to your hat.

Very exciting. You know, you mentioned in passing this possibility of rings in that Plutonian system. And my colleague, Emily Lakdawalla, just recently was talking about, gee, maybe this will present some challenges for your spacecraft. Is that the case? It could be. In fact, we're a little bit worried about that now that we've discovered three new satellites of Pluto and are concerned that there may be more. All those tiny satellites, because they're so tiny, don't have any real gravity to

them. They're not like Pluto, which has an escape speed of more than a mile per second, or the big moon Charon that's half that. So when they get hit by things in the Kuiper Belt, the debris sprays off of them. Instead of making a crater and ejector rays, it sprays off into orbit around Pluto, and all that debris represents hazards. If we get hit by something like that going at the speed we're going, 50,000 kilometers an hour, that's going to kill my spacecraft. So we are actually planning a second trajectory that goes farther from Pluto, and we may have to fire our engines on approach if we see rings or other hazards where we're going.

The backup trajectory has the best acronym in the Pluto mission, in New Horizons. It's called a safe haven bailout trajectory, or Shabbat. Uh-huh. They must like that some places. No rest for the weary, huh? Very creative. We do have the best acronyms in this business. You know, you told us last week that three years from right now, New Horizons will already be in the observation phase of its mission. But it isn't until July 14 of 2015 that you'll have your closest flyby. I didn't realize until I was on the website a little while ago

the significance of that date. It's quite an anniversary. Do you mean that it's Bastille Day? May we, but no, I was thinking of Mariner. Storming the gates of Pluto. That's right. I really was thinking more of Mariner 4. Yeah, it is an amazing anniversary.

It's by coincidence. We couldn't have designed it better. But we're actually arriving at the Pluto system, first reconnaissance of the third zone, the far zone of the solar system, the Kuiper Belt, the first reconnaissance of dwarf planets on the 50th anniversary to the day of the first flyby of Mars by an American spacecraft, Mariner 4. That's a pretty amazing coincidence, and it's a nice symbolic bookend to the beginning of the first era of planetary exploration that Carl

Sagan spoke and wrote so eloquently about, to the closing of that first era of reconnaissance, 50 years later to the day. And I'll tell you, thanks to Charles Elachi, who's the director of the Jet Propulsion Lab, we've actually got a mailing list from some of the engineers, the young guys that were on that project back in 1965, and they're still around and kicking, and we're going to invite them to our encounter. We can't wait. That's terrific.

Boy, July is always a good month for exploration, I think. Our guest is Alan Stern. He is the Associate Vice President in the Space Science and Engineering Division at the Southwest Research Institute, who has all of these things we've talked about and many others going on. In a moment, we're going to come back, right after our break, that is,

and talk to him about some things happening much closer to home, up on our own moon. This is Planetary Radio. I'm Robert Picardo. I traveled across the galaxy as the doctor in Star Trek Voyager. Then I joined the Planetary Society to become part of the real adventure of space exploration. The Society fights for missions that unveil the secrets of the solar system. It searches for other intelligences in the universe, and it built the first solar sail.

It also shares the wonder through this radio show, its website, and other exciting projects Transcription by CastingWords Planetary Radio. I'm Matt Kaplan, and my guest is Alan Stern of the Southwest Research Institute, the Space Science and Engineering Division. We've talked with him about New Horizons. We talked with him last week about this terrific conference he's hosting just about the time that this show is aired up in Northern California about suborbital space flights. But he has so many

things going on. Alan, I think the last time you were on, we did mention LAMP, but you've had some terrific new developments, including much more evidence about water hiding out at the poles of our moon. Yeah, we do. For everybody's background, LAMP is one of the instruments on the Lunar Reconnaissance Orbiter, which NASA has orbiting the moon since 2009. It's an ultraviolet spectrograph. One of my colleagues on the science team, Randy Gladstone, has actually turned up pretty good evidence of surface-lying frost on the polar regions of the moon. And this has been suspected for a long time, but I guess this is

maybe some of the best evidence so far, that this stuff is, what, hiding in these permanent shadows? That's right. There are papers going all the way back to the early 1960s predicting this kind of thing. And of course, just a few years ago, other spacecraft found evidence of water distributed around the moon in small quantities, and particularly at the polar regions, for example, with the L-cross impactor. But now we can see in the ultraviolet into these permanently shadowed regions because of the sensitivity of our instrument that lets us work by starlight and light reflected off the interplanetary medium, hydrogen, lime, and alpha. And we can actually see color ratios in the soil in the ultraviolet that are consistent with and pretty good pointers to surface-lying frost on the moon.

I neglected to say that LAMP stands for Lyman Alpha Mapping Project. That is this instrument on the Lunar Reconnaissance Orbiter. I guess it's showing us not just the water, but sort of the consistency of some of these soils. And that's brought up this terrific term. Are we going to find fairy castles at the poles of our moon? Yeah, that's a term that's meant to reflect the microstructure of the grains on the surface and how the light plays with them in sort of a fractal or fairy castle-type structure. And it's a fun term to use, so glad you asked. It really has a wonderful image that goes along with it, but basically this stuff is just fluffy?

It is probably fluffy, both due to electrostatic effects, charging effects in the lunar regolith or soil, as well as the fact that micrometeorites are constantly bombarding and churning and gardening the surface. And on a microscopic scale, it creates something that's very unlike what we're used to on the Earth, would be well-termed a fairy castle structure. I'm sorry, gardening? Gardening, you know, the turning over of the soil by the constant bombardment and splashing up of ejecta on every scale from the grains of sand that hit the moon all the way up to the biggest bolides and even asteroids that occasionally hit. Well, rock gardening on the moon, or rock and dust gardening, and ice watering.

Listen, one other result, something that you were able to announce just a few days before we put this program up, and this is some other results from LAMP having to do with the moon's, dare I say it, atmosphere? Sure you can say it. The lunar atmosphere was discovered back in the 1970s by Apollo 17 mission. And it turns out there are all kinds of species in the lunar atmosphere, just not much of any one of them. It's very tenuous, but it's actually a kind of atmosphere

called a surface boundary exosphere that's like Europa's and like many of the asteroids and satellites, these very tenuous exospheres. And we actually have now spotted helium in the lunar atmosphere from orbit. Apollo 17 had seen it on the ground with a mass spectrometer, but now we can actually map it from orbit and see how it changes. And we do think it's changing. And one of the interesting questions about it, the helium,

is it's unknown whether it's helium that comes to the moon from the solar wind or whether it's helium leaking out of the interior from the radiogenic decay of rocks. And we think we know how to test that hypothesis, which one it is, and that's whether or not this helium abundance is correlated with solar wind helium from day to day. So now that we've found it, we're going to go and try and understand the source and the origin of the helium. That's next on our plate. Alan, it has been, as always, a blast talking to you, and we didn't even get to some stuff like putting on a spacesuit and you getting swung around at 6 G's in a centrifuge. Maybe some other time. Anytime, and don't forget, please sign up for the stamp petition for New Horizons. We really appreciate it. And we will put that link up to

change.org where you can help get that stamp created for the New Horizons mission in time for its flyby of Pluto. Thank you, Matt. Thank you, Alan. Really a pleasure. Alan Stern is the Associate Vice President in the Space Science and Engineering Division at the Southwest Research Institute. He used to be the Associate Administrator for the Science Mission Directorate at NASA. Coming up next, another ex-NASA fellow, my friend Bruce Betts, will tell us about the night sky and much more. That'll be during this week's edition of What's Up. We've got Bruce Betts on the Skype line.

He's the director of projects for the Planetary Society. He will tell us about an exciting night sky. And then we'll get to some other interesting stuff. Welcome back. Thank you. So, last night, it was crazy out there. There were two big bright things near the moon. Those were airplanes.

No, the night sky is crazy awesome right now with planets. And in fact, it's going to get better. Better? Better. How could it possibly get? Go ahead. Tell me how. Well, what we've got now, what you saw last night, is Venus, super bright, low in the west in the early evening.

And above that is Jupiter, also super bright. And the first way it's going to get better, Venus and Jupiter are going to get closer over the coming days in the evening sky. So it's just going to be cooler because we're going to have the two brightest nighttime objects besides the moon getting really close together. And, of course, we've just had the moon nearby as well. But wait, don't order yet. If you look at Venus and Jupiter, we'll also throw in Mercury. That's right. Look even lower on the horizon.

You have to look very shortly after sunset. But in the coming days, and say centered around March 1st or so, and you follow it in a line because, you know because the planets, they orbit in a plane, so they end up roughly in a line in the night sky. Follow down from Jupiter and then down to Venus and then farther down to the horizon, you might be able to see Mercury if you've got a clear enough view to the low horizon. This is the best apparition of Mercury this year in the evening sky. And if you go the other direction and follow that line

up and around, quite a bit around, to the other side of the sky, we've got Mars. It is Mars opposition time. So Mars on March 3rd is on the opposite side of the Earth from the Sun, and right about that time, though not exactly, it is the closest it will be to the Earth for another 26 months. And so Mars is ridiculously bright too, not as bright as Venus or Jupiter, but nearly as bright as the brightest star in the sky and has that cool reddish-orange color. So that'll be rising in the east around sunset, and it will be setting in the west around sunrise, as objects do when they're at opposition. And you can complete the journey and see all five naked-eye planets in one evening.

If you look later in the evening, you can't see them all at the same time, but you can pick up Saturn, which rises around 10 p.m. in the east and will be high overhead in the pre-dawn sky. So all five naked-eye planets visible, Mars at opposition, cool stuff. Academy Awards, eat your heart out. Okay, well, let's go on because that took forever to get through all that excitement. Well, there are a lot of planets this week in space history. Fifth anniversary of New Horizons flying by Jupiter, still on its way out to Pluto in 2015,

New Horizons flying by Jupiter, still on its way out to Pluto in 2015, and the 40th anniversary of the first spacecraft to go out and fly by Jupiter. Ooh, that reminds me of a trivia question. That'll be Pioneer 10 launching 40 years ago this week. We'll come back to that. But first, random space fact. I think we're going to have a celebrity random space fact next week, but that's just a tease. Oh, that's exciting. Ganymede, of course, the largest moon in the solar system, has a diameter of 5,268 kilometers, for those keeping track at home.

It is 8% larger in diameter than the planet Mercury. It is 8% larger in diameter than the planet Mercury. But, despite being larger, Mercury has almost twice the mass of Ganymede, with Ganymede having an ice shell and Mercury having that dense iron core. It's almost twice as massive despite being smaller. All right, we move on to the trivia contest. We asked you what spacecraft have flown by Jupiter. How'd we do, Matt? Very interesting. A lot of people were disturbed or at least concerned about that word flyby, and they weren't sure whether to include Galileo because, you know, technically you could make the argument it didn't fly by, right? It stayed. It stuck around. As will Juno pretty soon.

We did have somebody who hedged his bets here, several people actually, but our longtime listener, many times entrant, but first-time winner as far as I can tell, Johan Peter Dam in the Faroe Islands off of Denmark. He came up with these, Pioneer 10, Pioneer 11, Voyager 1, Voyager 2, otherwise known, he points out, as V'ger, Ulysses twice, Cassini, New Horizons, and Galileo. That's perfect. I think you could argue Galileo either way, so officially we will take it in or out of the group. The one I think is interesting, because you wouldn't necessarily think of it, is Ulysses,

which, in order to study the sun, went out to Jupiter to get the gravity assist to shift its plane, and even went back by, though not as close, many, many years later to do another adjustment. Nice to think about that we've been out there that many times. Anyway, Johan, we're going to send you a Planetary Radio t-shirt. What do you have for us next time? All right. Well, I'm just kind of obsessed these days with what spacecraft have gone where and done what.

So what spacecraft went closest to the sun and how far away was that closest point? Go to planetary.org slash radio. Find out how to enter. You have until Monday, March 5th at 2 p.m. Pacific time to get us this latest hot answer. It's so hot. All right, everybody, go out there, look up at the night sky and think about if you had Matt record an audio book for you, what audio book would it be? Thank you and good night. I did record audio books.

I, once upon a time, many years ago, did that for a living. I think it would be Huckleberry Finn. He's Bruce Betts, the Director of Projects for the Planetary Society, one of the best-supporting planetary scientists award this year, and he joins us every week for What's Up. Planetary Radio is produced by the Planetary Scientist Award this year, and he joins us every week for What's Up.

Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by the Kenneth T. and Eileen L. Norris Foundation and by the members of the Planetary Society. Clear skies. Thank you.