Planetary Radio: Space Exploration, Astronomy and Science - Report on the Annual Meeting of the American Geophysical Union

Episode Date: December 22, 2008

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There's big news from the annual meeting of the American Geophysical Union this week on Planetary Radio. Hi everyone, welcome to Public Radio's travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. Our own Emily Lakdawalla joins us for an extended conversation this week. Emily spent some time at last week's annual AGU conference, where she caught the latest science

from our moon, from Mars, and from the moons of Saturn. Bill Nye, the science and planetary guy, will be along shortly. This week, Bill muses on the profound meeting of the sonic booms that recently shook his Southern California home. And we'll finish up at the holiday luncheon for the staff of the Planetary Society, where Bruce Betts will tell us about the night sky

and get seriously razzed by several special guests. He'll also present us with a new space trivia challenge that could win you a Planetary Radio t-shirt and an Oceanside Photo and Telescope rewards card. Emily includes some results from the Phoenix Mars Polar Lander mission in our upcoming AGU discussion, but there's a much more detailed report on Phoenix in her blog at planetary.org. It's largely based on Principal Investigator Peter Smith's long presentation at the conference,

along with sessions delivered by others on Peter's mission team. If you visit the blog, be sure to check out Emily's December 18 entry. Every now and then, we are treated to an image from beyond Earth that simply takes our breath away. This time, it's one taken by the Hubble Space Telescope of Jupiter with its moon Ganymede. Science is great, but you can't beat a picture like this one if you need something to remind you of what's waiting for us out there among the planets and stars. We also marked the passing of Steve Ostro this week. Some of you will remember our conversation with him about saving the great radio telescope at Arecibo almost exactly two years ago.

Steve combined a passion for radar astronomy with extraordinary ability. My colleague Charlene Anderson has written a glowing tribute to Steve at Planetary.org. Here's Bill. Hey, hey, Bill Nye, the planetary guy here, vice president of the Planetary Society. And this week, I just want to talk about an exciting thing. I was sitting in my house. What was I doing?

I was minding my own business when I heard this double boom, boom, boom. And everybody in the neighborhood was out on the street in just a few seconds. Everybody was outside and many of them assumed that the boom had come from my house as the science guy, my various little metalworking projects and so on. But no, they realized that I was at a loss just as they were. And then we all realized in a few moments when a 13-year-old, a guy named Eric, who lives across the street from me, said, hey,

that's the space shuttle. Come on, grownups, that's the space shuttle. And sure enough, the space shuttle had been rerouted because there were stormy conditions in Florida. It had been rerouted to Southern California. And we could hear it hundreds of nautical miles away. Now, the space shuttle flies all the time. And in fact, one of the ideas of the space shuttle was what? That we wouldn't even notice it. That going in and out of low Earth orbit would be routine, day at the office, nothing to be concerned with.

But when it happens, and the thing really works, and it produces a double sonic boom, which you see right there in your textbook, one from the nose of the spacecraft and one from the tail, and the two waves travel past your ear in the length of the spacecraft time. It's amazing. It's amazing. And it's inspiring to know that there are people on board. And I love robots. I'm kooky for robots. I design robots. I love the Spirit and Opportunity rover. I talk about them all the time. But there's something about humans, being on board and coming back to Earth, that was very exciting. Now, I'm the first to say that the space shuttle takes us to places we've already been. We go there so often that people don't remember the astronauts' names who are flying around right now.

Hundreds of them have flown in space, astronauts, taikonauts, cosmonauts. But this was a cool thing. And so with that said, I will claim again that when we get enough information about Mars to send people there, all of us all over world, will be very engaged indeed. We will be hanging on every moment of their flight. It will be exciting. And so remember that other countries, other space organizations besides the United States are going to send people to the moon, and that will be exciting. But it will be especially exciting when humans go to more distant destinations, to asteroids, Mars moons, and Mars itself. Oh, my friends.

All this from a boom, boom at the speed of sound. Well, thank you very much for listening. I hope everyone has a very good holiday season. Reminding you that, as reckoned in Britain, Isaac Newton was born on the 25th of December. So have a good holiday, and we will probably speak with each other again next year. Get it? Next year! Thanks for listening. I'm Bill Nye, the Planetary Guy.

You certainly know her from her regular Q&A contributions to this show. Many of you also look forward to every one of Emily Lakdawalla's regular entries in her blog at planetary.org. But the science and technology coordinator for the Planetary Society is also a trained geologist. So once a year she is drawn to the greatest gathering in her field. I sat down with her a few days after she returned to Southern California. It's rare that I get the chance to sit right across the table from Emily Lakdawalla, and so this is one of those very welcome opportunities. And we have good cause because you are just back from the annual meeting of the American Geophysical Union,

which is quite a show. 15,000 scientists? 15,000 geologists from all over the world convene in San Francisco once every year. And I always think what an irony it would be if the big one hit San Francisco while all the world's geologists were sitting there. It would certainly be well studied up close and personal. That's true. So obviously, it's mostly an Earth-centric conference, but some room for planetary concerns. That's true. So obviously it's mostly an Earth-centric conference, but some room for planetary concerns. That's true. It is the American Geophysical Union, so most people

there are using physics to study the Earth. But a lot of people who use physics to study the Earth are also interested in the rest of the worlds in our solar system. So there's two planetary tracks usually. And that's where you spent a lot of your time, obviously. That's right. I went to just one day of the meeting, but that one day was action-packed. It was filled with news from the Phoenix mission to Mars, the Kaguya mission to the moon, and the Cassini mission to Saturn and its moons. Let's start with Phoenix. What did you learn? Well, this was the very first time that Phoenix scientists actually presented some scientific results from their mission.

In the past, most of what they've talked about have been operational details, where they dug what trench when. This time, they finally gave us some numbers from their instruments. The two instruments that were most interesting to people are the ones called TIGA and WCL. TIGA is the Thermal and Evolved Gas Analyzer. It's the one where they put soil samples in and heated them to very high temperatures and sniffed the gases that came off to try to identify what chemicals were present in the soil, and also the isotopic ratios of the elements that were present in the soil. The information that they gave us was still pretty preliminary. They have identified that there was indeed water ice in the soil. There was also perchlorate, which has been discussed before, this oxidizing chemical.

And it turns out that the perchlorate may have caused a problem with trying to identify one of the other things they were looking for, which was organics. They'd be very interested to find organic chemicals of any kind in the soil, whether they came from space or came from Mars bugs. Are you saying that the perchlorate might have destroyed the organics or massed them? It might have destroyed them. Perchlorate is a potent oxidizer. And so when they put the soil into the oven and started heating it, one of the first things that may have happened is that the perchlorate could have oxidized any complex chemicals that were present in the soil. And at a fairly low temperature, they did get a reading of carbon dioxide having been given off. And that would be one of the things you would smell if you burned an organic chemical. But of

course, you could also get carbon dioxide at a low temperature from a lot of minerals. So the results are inconclusive. They're going to have to do a lot of laboratory modeling, make some simulated soils, try to make some guesses, educated guesses as to what was actually present, and run some laboratory tests to see if they can actually simulate the response that TIGA got from these soils. And how about that other experiment? The WCL, the wet chemistry lab, is the one where they brought a beaker of water from earth and they dumped the soil into it, stirred it up, and tried to see what ions it contained. They reported that the soil had a pH of about 8.3, which is very similar to earth soils, and that it contained about 5% by weight of a chemical called calcium carbonate, which you might know as calcite. It's a very common mineral

in earth soils and in earth's oceans. And one of the interesting things that the calcite. It's a very common mineral in earth soils and in earth's oceans. And one of the interesting things that the calcite does is that it buffers the acidity of the soil. So when they dropped an acid tablet into their beaker, the acidity didn't change at all because just more of the calcite went into solution. It's like Rolaids. Yeah, basically. And it does the same thing in earth groundwater. It keeps the pH at a level that's quite comfortable for Earth plants. So this is a very interesting finding. For a long time, Mars scientists had been wanting to find carbonates on Mars. They have found them from orbit, but I think it's great news that this particular carbonate, calcite, was detected

in Mars' soil. Sadly, our time is extremely limited, but we will, as always, suggest that folks visit your blog at planetary.org where they can learn more. And specifically regarding Phoenix, we're going to get Peter Smith back on this show. He has been incredibly busy, most recently at the conference, of course, but he'll be coming back on and we'll get it directly from the PI as well. We're going to go on to Saturn, but first, you had some visitors from Japan. That's right. There were four presentations made by scientists from the Kaguya mission, which is in orbit at the moon. Kaguya is a huge spacecraft.

It has a large number of instruments. One of its biggest goals was to study the gravity field of the moon. The gravity field is something that you can use to probe what's going on in the interior. If the moon were all had same topography everywhere and was made of the same stuff everywhere, then the gravity would not be changed throughout the orbit. But there are a lot of lumps and bumps in the gravity, and that tells you that there's little density differences inside the moon that tells you something about ancient volcanism. We have good gravity fields for most of the planets, but for the moon, we've had a hard time getting a gravity field on the far side,

because in order to get gravity, you've got to do radio tracking of a spacecraft. And since the spacecraft disappears behind the far side of the moon, you can't get radio tracking. You can't do line-of-sight tracking anymore. Kaguya solved this problem by having a relay satellite that relayed the radio signals from Earth through the satellite to Kaguya and back problem by having a relay satellite that relayed the radio signals from Earth through the satellite to Kaguya and back. So it was four-way Doppler tracking, and they unveiled their gravity map of the far side of the moon, which is much better than anything that had previously been produced. Okay. Still no discoveries of huge magnetic anomalies, right, that would unveil the monolith that's hiding from us? No, but they have done some

pretty cool laser altimetric maps of the topography of the moon, better ones that have been available previously, and they've got new numbers on how much of the area at the two poles of the moon is in permanent shadow, which is very important for future human exploration because it's hoped that in those permanently shadowed areas there might be little traps of water ice that astronauts could use. And let's hope that some of the upcoming missions, like the United States mission, will be unveiling more about those pole deposits that we all hope are there. That's Emily Lakdawalla, science and technology coordinator for the Planetary Society and author of the space blog at planetary.org.

Society and author of the space blog at planetary.org. Next, we'll venture out to Titan and Enceladus for the latest discoveries about those moons of Saturn. That's when Planetary Radio continues in one minute. 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 that reach around the globe. I'm proud to be part of this greatest of all voyages, and I hope you'll consider joining us.

You can learn more about the Planetary Society at our website, planetary.org slash radio, or by calling 1-800-9-WORLDS. Planetary Radio listeners who aren't yet members can join and receive a Planetary Radio t-shirt. Our nearly 100,000 members receive the internationally acclaimed Planetary Report magazine. That's planetary.org slash radio. The Planetary Society, exploring new worlds. Welcome back to Planetary Radio. I'm Matt Kaplan.

We're about to continue our conversation with friend and colleague Emily Lakdawalla. Emily is the Planetary Society Science and Technology Coordinator and the power behind her great blog at planetary.org. She joined me shortly after returning from the annual meeting of the American Geophysical Union in San Francisco, where she joined 15,000 other geologists in getting the latest science from all around our planet and throughout the solar system. Let's do go on to other very cold places, out to Saturn. And it sounded like most of what you heard focused not on the big ring planet itself, but on a couple of its interesting moons.

That's right. The sessions on Monday focused primarily on two of Saturn's moons, Enceladus and Titan. These two worlds are extremely different. Titan is the second largest moon in the solar system and the only one with a significant atmosphere. The atmosphere contains nitrogen primarily, which is what Earth's atmosphere has. But the second gas in Titan's atmosphere is methane. And methane behaves a lot like water does on Earth. It exists in the atmosphere. It forms clouds. Under the right conditions, it might rain or snow, and it appears to fill lakes at Titan's North Pole. So we've got lots of weather. It does have lots of weather. It has lots of interesting, they keep on calling it hydrogeology, but some scientists call it

methanology or a methanological cycle. They keep on forgetting not to think of it as water because it's most emphatically not water. In fact, the water on Titan is the rocks. What we would think of as rocks on Earth, it's the ground. It's made of water ice. So one of the mysteries that they've been probing at Titan is the fact that the lakes only occurred primarily at the poles. And they figured out that this is probably a seasonal thing and that the climate is correct at the poles to have the methane rain. The problem is when they continued studying Titan, they found that there were lots of lakes at the North Pole and almost none at the South Pole. So all of a sudden, this seasonal explanation started breaking down.

And they had to figure out some other reason why there would be no lakes at the South Pole. There were two different explanations advanced. One of them is that Titan is simply asymmetric in its shape, that the South Pole is higher in elevation than the North Pole, which is why you might get lakes predominantly at one pole. And this is not crazy. Mars is shaped that way too. And so if Mars ever had oceans, they would primarily have been toward its north pole. So this isn't nutty. And there's some data indicating that it may be correct. The other theory is a bit more complicated, and it has to do with an asymmetry in the way that Saturn's seasons play out on the planet, because Saturn has an elliptical orbit.

An elliptical orbit means that you're moving faster when you're closest to the sun and much slower when you're farthest from the sun. And the seasons line up with this orbit in such a way that the southern summer is much shorter and more intense than the northern summer. And it might be that that creates enough of a climatic difference

that you could wind up with lakes in the north only, but that the conditions would not be right for you to wind up with lakes in the south. Yikes, that's a little belabored, but I guess- It's complicated. We have a lot more to learn. Absolutely. Well, it's actually a very similar explanation as to why Mars predominantly has a carbon dioxide cap in the south and not so much in the north. It's exactly the same thing as applying on Mars. So lots still to discover about what's happening above the surface on Titan. How about below?

How about below? Well, there's another debate going on that's really almost polarizing the community, which is whether there's ever been cryovolcanism on Titan. That's ice volcanism where water is the magma, and it comes out in a liquid form and freezes onto the surface. And if it's ever happened, if it's currently happening now, there's a vocal group that believes that they've seen evidence for change on Titan that they think results from volcanism. There are other people who are not convinced. And as a way of trying to crystallize

those arguments, there is one guy, Jeff Moore, who presented a talk titled Titan colon Callisto with weather. And I should explain that Callisto is one of Jupiter's large moons, and it's often regarded as one of the most boring places in the solar system. It's a huge moon. It should be interesting, but it's got an incredibly ancient surface, more than 4 billion years old, nothing but craters, very little seems to have ever happened there. And so the idea is that the only features that we've identified unambiguously on Titan are craters, rivers, lakes, and sand dunes. All of these things result from influences that happen outside of the solid world of Titan itself, from either weather or from craters. None of them requires anything to be going on geologically inside Titan to make them happen.

That's sort of an opposing argument set up to say, you know, you really, really have to prove that you need volcanism to explain these features that you observe on Titan. Because right now, there's not actually great evidence for Titan being that geologically active. The only thing that you can really point to is the fact that there's methane in the atmosphere, which should be destroyed by solar radiation on a pretty short timescale within a couple millions of years. So you have to do something to replenish that methane. But volcanism is not the only explanation. We have maybe a minute left to move to a different moon of Saturn, one where the situation is almost reversed, not much in the way of weather, but apparently a lot going on below the surface. Yeah, there's no question that

Enceladus is geologically active. There's huge geysers sprouting from the South Pole. And scientists are trying to investigate the what, why, where, and how that geyser activity is happening, one of the big pieces of news at the conference was that they think that there is spreading happening at these long linear vents where the surface of Enceladus is actually opening up, spreading apart, that there's new crust being created at these vents, kind of the same way that it happens in the middle of the oceans on the ocean floor on Earth. Well, that immediately makes me think that if you could drop something down onto that vent, you could learn about the composition of the stuff that's way underneath the surface. Well, and that's why Cassini's been flying so close to Enceladus recently. It's most recently

flown within 25 kilometers of the moon and flown right through the plume to sample it. recently flown within 25 kilometers of the moon and flown right through the plume to sample it. I was not there for talks on what it did taste when it flew through the plume, but that is an ongoing area of study, what Enceladus' interior is made of, because it's very helpfully spewing its interior out into space for Cassini to sample. So much more that we could talk about. Much of it you will be putting on the blog. Much of it is already there.

Be prepared to dig into the archives a little bit because Emily does keep adding new material to the blog at planetary.org. But we'll continue to look to you for letting us know about other things that are going on around the solar system, particularly in Q&A, but hopefully also with other visits like this one. Thanks, Emily.

Thank you. Emily Lactewal is the Science and Technology Coordinator for the Planetary Society, just back from the AGU conference, just completed in San Francisco. And she'll be back with us again next week with her usual Q&A contribution. I'll be back with Bruce Betts and this week's edition of What's Up in just a few seconds. Time for What's Up on Planetary Radio. Bruce Betts is here, the director of projects for the Planetary Society. And what is this, the official restaurant of the Planetary Society, Burger Continental? It is indeed, and we're having a festive holiday celebration.

And it's a beautiful day for it too here at the end of the year of 2008 and a special guest joining us for a minute or so. Would you introduce them? Do I have to? Yes you do. Start with your former professor. Dr. Bruce Murray, member of the board of directors of the Planetary Society, one of the original founders, Caltech professor emeritus all around, great guy, Mars scientist, planetary, know everything, know it all. Stop kissing up and speed it up. And here's Bruce Murray. Well, that's an overwhelming introduction from an otherwise mediocre student.

But I learned to love him, and he's proven to be quite productive and I welcome. And with that in mind, I'll introduce our special guest, leading figure, Bill Nye. Greetings, everyone. It's Bill Nye, the science guy, vice president of Planetary Society. I'd just like to wish everyone a very happy and safe holiday season. And here's to a great 2009. 2009. Nine years into the new millennium. Or ten years if you count the zeroth.

It's exciting. Several events on Mars coming up in January. We have the fifth anniversary of the Mars Exploration Rover Spirit and Opportunity. We have missions to Mercury. We're going to be studying the Earth's atmosphere from space. And you can all be part of this by listening to Planetary Radio. So thank you for your support. It's an exciting time in space exploration.

Now may I introduce the Executive Director of the Planetary Society, Dr. Lou Friedman. Hi, and I'm really glad. One of the great virtues of working in the Planetary Society is working with great people. Bruce Murray was, of course, my mentor at JPL and then with the Planetary Society, co-founder with Carl Sagan, now working with Bill Nye is a great honor, working with the staff. We're out here celebrating our staff lunch today at the restaurant and I just want to wish everybody a happy 2009. Let it even be a bigger one in space. Thank you, gentlemen. And how about this for a coincidence? That other party that was here

with us? I recognize some of those people. I wish we'd caught Steve Squires. This was the holiday party choice for the Mars Exploration Rover team as well. I love working in this town. the Mars Exploration Rover team as well. I love working in this town. It is pretty interesting. What do you got for us? All right, we've got up in the evening skies, still Venus looking incredibly bright,

fabulous over there in the west after sunset. You can also still probably catch Jupiter below it, the other bright star-like object, but Jupiter getting tougher and tougher over the next few weeks. We've got Saturn rising around midnight over in the east, and then it's up high in the sky in the south before dawn. And coming up on, peaking on January 3rd, a kind of middle-of-the-road kind of meteor shower that quantrintids. You did that well this time.

How was that? That was better? I've been practicing every night. And that's the quick run around the sky, which leads us to Random Space Fact! You didn't know he could do that when he was in school? No, I didn't. He has all sorts of hidden talents. Let's hope they stay that way, too. Oh, man. That's a tough episode for me.

Big telescopes. We're talking big telescopes. Many of the primary mirrors for big telescopes in recent years. Not one big single hunk of glass, although we'll come back to that in the trivia contest. Often made of different independently movable segments. So, for example, the 2K telescopes in Hawaii, both with 10-meter primary mirrors, they're actually made of 36 hexagonal segments that form the primary mirror, and they can adjust those independently to get a nice surface,

and that's our random space fact. But we'll come back to big mirrors because I like them. Then we're going to move on to the trivia contest? We are indeed. We're going to move on to the trivia contest. And we asked you about the supernova that occurred about 1,000 years ago and what the leftover remnant nebula from 1054 is from that supernova. What's it called and what is its Messier number in the Messier catalog that we talked about a couple shows ago. How'd we do, Matt? Boy, you made so many people happy with this. The common refrain was,

hooray, uneasy one. They loved that you gave them something simple this time, because you've had some tough ones lately. And so we had more answers, I think, more responses than we've ever had. Every single one was correct. So what do we do when that happens? We rely on random.org. And random.org selected for us William Stewart. William Stewart of Ravensmoor, Nantwich, Cheshire. Boy, they have the longest addresses in the United Kingdom. Anyway, he came up with the answer, which is? Crab Nebula, M1. That's right, number one.

Which also we were told by some people, NGC 1952. Kevin Hecht pointed out, there was a 50 light-year kill radius. And so it's good that we are several thousand years away from the crab nebula, I suppose. Fortunately, there were only various wildebeest and antelope in that kill radius, as far as we know. We had another good comment from Aaron Baranovsky, who pointed out that M1 is good because anything with a Messier number higher than 15 is just a poser, really. Well, as you pointed out to him, I believe there's some impressive posers in those higher numbers.

All right, let's go on to the next trivia contest. Talking about big mirrors back in the day, and they still make some really big mirrors, but the Palomar 200-inch, of course, one of the most famous big all-hanging mirrors. My trivia question, what kind of glass, what's the name of the glass blend that's used for the Palomar 200-inch primary mirror? Go to planetary.org slash radio to find out how to enter. And you have until the 29th, the very last Monday of the year 2008, the 29th of December at 2 p.m. Pacific time to get us that answer. All right, everybody, go out there, look up at the night sky, and think about your favorite holiday decorations. Thank you, and good night. Bruce Betts is our festively decorated partner for What's Up.

This time, coming to you from Burger Continental in Pasadena, California. He's the director of projects for the Planetary Society, and you've been listening to What's Up. Planetary Radio is produced by the Planetary Society in Pasadena, California. Have a great week. Редактор субтитров А.Семкин Корректор А.Егорова