Planetary Radio: Space Exploration, Astronomy and Science - Pluto Will Finally Get a Visitor

Episode Date: July 14, 2003

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This is Planetary Radio. Welcome to an all-new, all-singing, all-dancing Planetary Radio. I'm Matt Kaplan. What do you do when there's a planet in your solar system that is so distant you really know almost nothing about it? You go there, of course. Alan Stern is Principal Investigator for the New Horizons mission to Pluto and beyond, launching in 2006, if all goes well. He'll be here to talk about this mammoth voyage and a few of the other projects that make him a very busy planetary astronomer. Bruce Betts is on the road doing microgravity research, sort of,

and calling in with a new trivia question. First, though, Emily is talking about the weather, and it's looking stormy. Hi, I'm Emily Lakdawalla with questions and answers. A listener asked, Why are Jupiter's great red spot, Neptune's great dark spot, and their small subdued counterparts on Saturn all in the southern hemispheres of these planets?

All of these huge cloud systems in the atmospheres of the giant outer planets appear to be storms in which atmospheric gases are rising and expanding. If that's true, they are similar to storms in Earth's mid-latitudes and should not be seen to favor either hemisphere. The question of why giant planet storms seem to be confined to the southern hemispheres has plagued planetary scientists, and we just don't know the answer. It may just be a coincidence, because while Jupiter's great red spot has been observed for over 300 years,

other storms in the atmospheres of Jupiter, Saturn, and Neptune don't appear to be as long-lived. Stay tuned to Planetary Radio to find out more. On May 29 of this year, the Los Angeles Times featured a page one article titled, So Far, Yet Now So Near. If the star of that piece was the planet Pluto, you could say Alan Stern was best supporting actor. Dr. Stern directs the Department of Space Studies at the Southwest Research Institute in Boulder, Colorado. That's where we found several of our special guests on Planetary Radio in the past. He joins us from there now.

Welcome, Alan. Hi there, Matt. How are you doing? Very well, thank you. And that was quite an article in the L.A. Times. Well, Usha McFarling is a really talented writer, and it was a spectacular article, as you say. She really captured the story.

And this is a story that has been pretty near and dear to your heart for a lot of years now. It has, and that's a story in and of itself, isn't it? Yes, it is. We should say that a mission to Pluto is something that you have dreamt of for a long time. Now it's going to happen. It's called New Horizons.

Of course, it's also a mission that the Planetary Society had a role in supporting, helping to make that come about. But you are going to play a very central role in this mission. Well, I'm the principal investigator. You know, NASA thinks of principal investigators as the Harry Truman of the endeavor. You know, the buck stops here. And are you finding that to be the case? Yeah, that's the way it works.

You know, whether it's at the level of being what we call a PI for principal investigator, at the instrument level where an instrument goes on a spacecraft, this is new for me doing an entire mission. It's very much the case that when NASA wants to bring up a problem or resolve something, they take up the phone and find my number any time of the day or night. So they're going to keep you busy for a few years, because when will New Horizons head for that little rock? Well, departure is in January of 2006.

And it's going to take how long to get that far? That depends upon which day in January we launch and what launch vehicle we select. It could take as long as a dozen years, but much more likely it'll take us eight and a half or nine and a half years. it'll take us eight and a half or nine and a half years. And is that because you will be taking the kind of trajectory that the wonderful Voyager spacecraft did before you, where you'll be slingshotting around other planets, or are you taking a more direct route? Well, if we launch in January of 06, we will go direct to Jupiter,

and then off, it's one left left turn and we're off to Pluto. If we launch after that, later in 2006 in particular, we have a launch window in February, or in 2007, for example, if something were to keep us on the ground, then that would be a direct shot because Jupiter is not in position any longer. But I have to say, we're building a very small spacecraft and buying a very big launch vehicle, and so we're traveling quite a bit faster than Voyager. Huh. Yeah, your spacecraft is, what, only about 900 pounds? Well, closer to 1,000 with fuel. But, you know, when you put that on the biggest missile

you can find, you know, one of the biggest types of missiles you can find, the end result is a very high launch speed. Consider this. The Apollo spacecraft took three, three-and-a-half days to reach the orbit of the moon. We're going to do it in a matter of hours. Galileo and Cassini took six years to get to Jupiter. We're going to do it in 13, 14 months, depending upon the details. Wow, that's amazing.

So we're really, you know, humming. I suppose that, in your opinion, the upon the details. That's amazing. So we're really, you know, humming. I suppose that, in your opinion, the sooner the better. Oh, absolutely. There's enough delayed gratification in this mission. Tell us, with apologies to you and to our regular listeners who know the answer to this question, why should we be so curious? Why should we be spending still not a huge amount of money in planetary exploration terms, but a few dollars

to reach this rock which some people now question whether it's even a planet? Well, I think there are sort of two ways to answer that question. I'll give you both. One way is scientifically. The National Academy ranked this mission at the very top of the to-do list for this decade in terms of planetary exploration because we're going to a whole new realm of the solar system,

visiting new types of objects and getting a brand new kind of window into the origin and birth of our solar system. And that racks up to a pretty important suite of objectives. But you know, there's also just the human perspective. This is a mission of first-time exploration. It's been a long time since NASA's done anything like that. We've had very successful returns to Mars, to Jupiter, very shortly to Saturn. We could go down that list. But putting a little bit of the excitement of the old days, of first-time exploration back, I think, has really got people jazzed,

ranging from Planetary Society members to the general public, to school kids. And it's got me excited. I very unfairly called it that little rock out there, when really, even though we don't have a huge amount of data on Pluto, because it is so far away, there are already some very intriguing mysteries. Well, there are. And, you know, it is a little spit of a planet on the distant edge of the solar system. There's no kidding ourselves about that.

In fact, that's part of what makes it so interesting. I remember, even before I was interested in astronomy, you know, I can remember in grade school being taught that there are four rocky planets, sort of like the Earth in one way, small planets on the inside of the solar system, and four gas giants, and then this oddball spit of a planet covered in ice, or a strange elliptical orbit called Pluto. And I can remember being a little kid and wondering, who ordered that? How did that get to be that way? Why is it so different? In fact, it turns out that Pluto is just the tip of an iceberg,

the largest of one of, well, over 100,000 Kuiper Belt objects. And so when I was a kid growing up in the 60s, we couldn't detect the Kuiper Belt objects, and so when I was a kid growing up in the 60s, we couldn't detect the Kuiper belt objects, and Pluto looked like it was without context. But now we see pretty clearly that it fits in pretty naturally. There's kind of an asteroid belt beyond the giant planets of icy objects, unlike the rocky asteroid belt between Mars and Jupiter. And Pluto is the king of the Kuiper belt.

So in a way, is New Horizons as much a mission to the Kuiper Belt as it is to Pluto? Oh, absolutely. In fact, NASA calls the mission the Pluto Kuiper Belt Mission, PKB. Once we have waited those years, depending on when you launch, as you said, and we get out there, what kinds of instruments, what will New Horizons be able to tell us about this little planet and its neighbors? Well, we're going to make a very thorough study of the Pluto-Sharon system and then go on to Kuiper Belt objects. We're carrying no less than eight cameras with various resolutions and color capabilities.

We have spectrometers to actually map surface composition at every pixel on Pluto, on Charon, on KBOs. We have instruments to study the atmospheres of these objects, their ionospheres, if they have them, by remote sensing, meaning by the light that's coming from the atmosphere. And also, we have instruments that will actually sample the material that's escaping off the atmosphere to tell us more about that escape rate and also about the composition of the material. And in addition to that, we're carrying gear that will allow us to measure the surface temperatures, not only the basic surface temperatures, but to map the surface temperatures across

each world that we visit. Very exciting. It's going to be difficult to wait, I think, for a lot of us who will be anxious to see those pictures. Our guest is Dr. Alan Stern of the Southwest Research Institute, a central figure, as we said, in the New Horizons mission to Pluto. We're going to pause now for a quick break, and then we will be right back with Alan Stern here on Planetary Radio. 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. You can learn about these adventures and exciting new discoveries from space exploration in The Planetary Report. The Planetary Report is the Society's full-color magazine. It's just one of many member benefits. You can learn more by calling 1-877-PLANETS. That's toll-free, 1-877-752-6387. And you can catch up on space exploration news and developments

at our exciting and informative website, PlanetarySociety.org. The Planetary Society, exploring new worlds. ORG, the Planetary Society, exploring new worlds. Alan Stern is our special guest this week on Planetary Radio. He is the director of the Department of Space Studies at the Southwest Research Institute in Boulder, Colorado, and that's where we find him, other end of our telephone line today. Alan, we're going to bring it considerably closer in on the solar system to some other

mysterious objects, which have been really only theorized. I'm not sure that anybody has actually found actual proof that they exist, but maybe you'll correct me. They have that wonderfully intriguing name, vulcanoids, and this is another major area of interest for you. Well, it is. It's something that I and my colleague, Dan Dirt, have been working on for a few years. It's to find out whether or not there's an asteroid belt inside of Mercury's orbit. This has been theorized for over a century, and yet it's so difficult an observation to make due to the proximity of the sun that no one knows the answer.

And that's really it. It's just so hard to pick out these what must be fairly small objects with that bright light right next to them. That's the whole problem. These little guys are lost in the glare of the sun. Now, we talked to Dan Durda a little bit about this, and we talked to him about, in fact, I accused him of half just wanting to have that fun experience going up in the F-18s. You also get to take those rides. That's right.

Well, I was flying other high-performance NASA aircraft before the Volcanoids worked, as was Dan. We enjoyed it a lot, but also it's a very, very apt tool for certain types of airborne astronomy. Much lower cost than base observations, and in fact, lower cost than, I believe, any other kind of airborne astronomy, and allows us to do some things you can't do in big aircraft. I still find it amazing that you can fit any kind of useful scientific instrumentation in that already very tight cockpit. Well, we fly a very high-tech, image-intensified camera that frames at 60 hertz, 60 frames a second, so that we can, with a computer on the ground afterwards, take the jitter, the very slight jitter from the aircraft motion out. We're able to get down to 13th magnitude or

better on a dark sky and see very faint objects. That corresponds to things that are pushing, not quite, but pushing thousands of times fainter than your eye can see. Any tantalizing evidence? Not from our work, not yet. We've been able to constrain the possibility of the volcanoids down pretty far. If they're there, they can't be more than a few hundred, and they can't be much bigger than 10 kilometers across.

However, if you look at the face of Mercury, you see a lot of craters, and those are caused by impactors, many of which may have been vulcanoids long ago. I think I'll find it surprising if all the evidence, if every last one is gone, but that's what we're out to find out. We mentioned Dan Durda, of course, a colleague of yours, another colleague, William K. Hartman, Dr. Hartman, Bill Hartman, has also been on the show. There seems to be a, oh, I don't know, a fraternity, I'd call it a brotherhood, but some of them are women, of folks like you who are extremely curious about what is happening within our solar system,

and in some cases beyond, and learning about it, but really taking first-hand action to do this kind of research. And you certainly qualify those times up in F-18s. I know you spend time underwater as well, and in some of the more forlorn places on our planet. Do you get the feeling that you're in kind of a special club with people doing this kind of research? Well, it's select in the sense that not many people get to live their dream. I don't know that it's any more than that, really.

I tell you, I think I only speak for myself, but I'm having a ball, and I think we're learning new things. having a ball, and I think we're learning new things. And therefore, I think that's what astronomers contribute, is a better perspective for all of us about our place in space and where we came from. You've been able to collect some of these colleagues periodically. The latest example of this is in a book that the paperback edition has just come out from Cambridge University Press. It's called Worlds Beyond. I've had a ball reading it over the last few days, just got it a few days ago.

And it is a wonderful collection of essays, not just about these worlds in our solar system that we share a star with, but about why a lot of these people have gone in this direction. And you have one of these essays. I guess that's the editor's prerogative, right, to have the last entry? Well, my boss at Cambridge University Press asked at the end of the third book, did I finally write one of these myself? So I did. This is, as I said, the third in a series of three, the last in a series of three books, all done by Cambridge University Press. I

was the editor for all three. And the concept was to have astronomers, planetary astronomers or astrophysicists, write in first person about objects or types of objects that they'd invested large parts of their career in, basically challenging them in their essays to not just transmit the frontier astronomy, but also to tell why they're interested in a given body, like the moon or Pluto, or in the case of our universe, which was about astrophysics, those topics. You have not only these wonderful essays,

and I enjoy reading the motivations of these people as much as I do the incredible findings that they've made, but you also have these beautiful colored plates, some of which are examples of artwork from your colleague Bill Hartman. That's right. Bill was an author in this book. In the third book, we wanted to really go beyond what we'd done in the first two and pick some types of authors that weren't just strictly astronomers, research astronomers only, but had other interesting aspects to their careers.

For example, Jack Schmidt, who was aboard Apollo 17 and walked on the moon, writes about the return to the moon. You can call him Jack. I have to call him Senator, I think. Well, he is a former Senator as well. And Bill Hartman, who you mentioned, who does, in addition to his research career as an artist, writes about planetary science with a paintbrush in hand. We asked Kelly Beattie, who's a very well-known planetary science reporter for Sky and Telescope, to write about covering planetary science. And then in addition, there are the normal sorts of articles, like the other books, where folks write about their interest in a given

body, like in this book. We cover Mercury. We cover Pluto. We cover the asteroids. There's an article about roving on Mars by Matt Kolombek of JPL there in L.A. who was in charge scientifically of the Pathfinder rover and rover mission back in 1997. Another former guest on this program. You have won by a very young-looking woman.

Robin, is it Canup? Robin Canup, that's right. And she's a very accomplished scientist. Robin is just the newly awarded Urey Prize winner of the Division of Planetary Sciences. She's an outstanding theorist who's really made great advances in understanding the origin of the Earth's moon, and that's what she writes about. And the book is available from Amazon?

It is, and it's available anywhere. Cambridge University Press distributes. They have book clubs, and of course, they have their own website, and they're in many, many bookstores. It is called Worlds Beyond. The subtitle is The Thrill of Planetary Exploration.

It really communicates that thrill. And I think you do too, Alan, and it has been a great pleasure talking with you. It's been a pleasure talking to you, Matt. And we will post the URL for the website at SWRI and the Department of Space Studies, if you don't mind. Yeah, go right ahead. That's great. Thank you very much, and I'm sure we will want to check into you as we get closer to the launch of New Horizons,

and hopefully we'll still be doing this thing when you reach Pluto. I hope so. It's a lot of fun, and I'll look forward to doing it again. Alan Stern has been our guest. He is the director of the Department of Space Studies at the Southwest Research Institute in Boulder, Colorado. We'll be back in just a moment. I'm Emily Lakdawalla,

back with Q&A. It's difficult to get a perspective on how the giant planet atmospheres change over time without constant observation by orbiting spacecraft. Luckily, the Hubble Space Telescope is sharp enough to observe changes on these planets. Hubble has confirmed that a storm observed by the Voyager spacecraft in the northern latitudes of Saturn's atmosphere has persisted for at least 15 years, and it has also been used to discover a new huge white storm blooming near Saturn's equator. Hubble was also used to observe Neptune, where it found that the great dark spot discovered by Voyager had

disappeared by 1994, while new dark spots had appeared elsewhere in Neptune's atmosphere. Over time, Hubble has discovered that Neptune's southern hemisphere appears to be brightening, leading to the conclusion that Neptune, like Earth, may experience seasonal change. Our understanding of the long-term behavior of storms in giant planet atmospheres will continue to increase with the help of Hubble and planetary spacecraft, particularly Cassini when it arrives at Saturn in July of 2004. 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 again for What's Up with Dr. Bruce Betts. And Bruce, you're on the road again doing research? I am indeed. I'm in California's Bay Area doing microgravity research. Okay. Now tell the truth. You've been bouncing, haven't you? All right.

I was playing in a bounce house. But still, that's kind of the same. Playing and trying to keep your child from being bounced on. I was going to say, my boys were there. It isn't as bad as it sounds. It was microgravity research. I think it's legit. What do you have for us this week?

Well, what's up, Mars? Mars. And Mars. Look for Mars. Good stuff. Ignore the rest of them. They're too hard to see. Go looking for Mars.

It rises about three hours after sunset in the east-southeast, and will be up the rest of the night. Extremely bright, brighter than anything else out there. Red-orange, getting brighter as each week goes along through the end of August. And on the evening of the 16th, all the way through the following morning, you can watch the moon close in on Mars. And in fact, for our listeners in southern Florida, you can actually see the moon will actually occult Mars and go in front of Mars.

Also true from a few other locales. If you have any trouble finding the moon or Mars, look at them together the night of the 16th. Excellent. Okay. Let's move on. This week in space history, quite historic. June, July 20th, 1969, Apollo 11 astronaut Neil Armstrong steps onto the surface of the moon, becoming the first human to ever walk on another world. July 20th, 1976, the U.S. Viking 1 lander landed on Mars,

becoming the first successful Mars lander. I think two of the greatest days in all of human history. True, true, true. Speaking of great, random space fact! Jupiter's moon Ganymede, the largest moon in the solar system, has a surface area that is approximately half that of the Earth's land surface area. So I'm not including the Earth's ocean, about half the surface area, Jupiter's moon, Ganymede. So we move to the trivia contest.

Let's do that. That's what so many people are waiting for, to find out the answer to last week's trivia question. Last week's trivia question, what is the name of the tiny moonlet orbiting the asteroid Ida? The answer being Dactyl. And how did we do with the winner out there? We did very well.

Everyone got it right. And not a few people even provided the mythological basis for the fact that that moon is named dactyl. Here is one that somebody sent us. It's derived from the dactyli, a group of mythological beings who lived on Mount Ida. The dactyli protected the infant Zeus after the nymph Ida hid and raised the god on the mountain. Isn't that something? That is incredible.

I did not know that. Thank goodness for our listeners. Yes. I actually had some dactyli, but I was able to get them removed. That's good. It's a wonder what they can do with modern medicine. It really is.

And speaking of our listeners, there is Alex Chapman out there. Alex, who enters just about every week. He hails from Manchester in the United Kingdom, and he always has something to entertain us when he enters. This time he said Alex Chapman pronounced his wife has no idea why he is obsessed with winning a 3D poster and getting a mention. Well, guess what, Alex? You're halfway there.

I'm sorry, Alex. You didn't win, but you did get a mention. Displaying Matt's occasional cruel streak, but hey, keep trying. Yeah, well, you know, we were talking about this, Bruce and I, and I said it's a win-win because, you know, I get a little cruel fun out of it and Alex gets his name mentioned. Exactly.

But we, sticking to random selection, have determined whom to be the winner. Here it is. Mark Vromans, who lives in Merrickville, New South Wales, Australia. We actually had a couple of Aussies enter with the correct answer this week, but Mark was the one whose lucky number was chosen. So, Mark, you'll be getting that wonderful Mars 3D poster and our appreciation. Excellent. How about a new trivia question?

Yeah, how about one? Where in the solar system can you find the Valhalla Basin? Hmm. Valhalla Basin. The Valhalla Basin, that is the mythical, or you know, who knows, maybe not mythical, what, paradise of the Vikings, isn't it? Indeed. Although I suspect they didn't have in mind wherever this actual one is. A little nippier than what they had in mind. Oh, a hint, a hint. There's your hint. Well, there you have it, folks. How do they enter, Bruce? Go to planetary.org,

follow the links for Planetary Radio, and it will tell you how to enter. Do you want to mention one other thing before we're done, which is after quite a number of tries and many days, weeks of waiting, the Mars Exploration Rover B mission did launch on July 7th

with Sandy Moondust Astrobot on board. To read more about the launch and the adventures of Sandy Moondust and Biff Starling, Astrobots in Space, keep listening to Planetary Radio, and you can also go to redroverghostmars.org slash astrobots. And anybody who might be wondering why we don't have Sandy on this week, well, she's kind of busy up there. You've got to get everything locked down and reconfigured for the long, although not as long as usual, trip to Mars.

But I'm sure we'll have her on soon, right, Bruce? Very soon. She's also still very busy answering Biff's questions. Yeah, I think he probably has a lot. Yeah, although most of them are about video games, which frustrates her. We'll get back to that later. I bet we'll hear from Biff, too. Oh, yeah.

That's it. I guess we'll have you back at home next week. We will. Doing it live in the studio, sort of. Look up in the night sky and think about what your form of paradise would be like. Thank you, and good night. That's a nice one, a thoughtful, nice one from Dr. Bruce Betts, the Director of Projects

for the Planetary Society. He joins us each week for What's Up, but you knew that, didn't you? Yeah. I might keep that. That's it for this week. Thanks to all of you for listening, and especially to everyone who has written to us.

We try to answer every message. You can tell us what you think of our little show by sending email to planetaryradio at planetary.org. That's planetaryradio, all one word, at planetary.org. And remember that you can find all of our past shows and a lot of other great information on the Planetary Society website, planetary.org. Have a great week.