Planetary Radio: Space Exploration, Astronomy and Science - Help Us Find Star Dust at Home!

Episode Date: May 1, 2006

Stardust mission researcher Andrew Westphal returns with news about what the spacecraft brought back to Earth, and how the public will help find more.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Will you be the first to see dust from another star? 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. Andrew Westfall of the Stardust Mission returns to our show with amazing news I'm Matt Kaplan. and help discover these tiny bits of matter that may have traveled light years to reach us. Looks like everybody's traveling this week as we catch Bruce Betts on the freeways of Southern California. He'll provide a night sky traffic report,

along with another opportunity to win one of our ultra-fab planetary radio T-shirts. The International Space Development Conference tops our news this week. The ISDC may already be underway, as many of you hear this show. Over 1,000 people are pre-registered for the biggest event ever, with everyone from Spaceship One designer Bert Rutan to Planetary Society chairman Neil Tyson attending. Longtime sponsor, the National Space Society, has been joined for the first time by the Planetary Society for the Los Angeles Gathering.

It runs from Thursday, May 4, through Sunday, May 7. You'll see regular updates at planetary.org, and we'll bring you highlights on next week's show. And how about news that actually comes from space? Will you settle for bytes from space? How about 139 billion of them? That's about how much data has been returned by Cassini as it circles Saturn. But that number is deceptively small. As Emily Lakdawalla points out in her blog,

the data returned by the orbiter has been heavily compressed, for obvious reasons. Besides, it's quality, not quantity, right? Back to comets for a moment, as we consider 73P Schwarzmann-Wachmann 3. Apparently depressed by its less-than-sexy name, the dirty snowball has broken up into more than 40 fragments. The biggest piece will be passing by us at a distance of about 7.3 million miles on May 12. Some of the others may get a bit closer, but you'll still need a small telescope to see them, and none will get anywhere near as close as the moon. But someday, one of these guys is going to take a shot at us.

Up next, Emily takes a shot at explaining how Venus got such a thick atmosphere. I'll be right back with Andrew Westfall and Stardust. Where's Hoagy Carmichael when you need him? Westfall and Stardust. Where's Hoagy Carmichael when you need him? Hi, I'm Emily Lakdawalla with questions and answers. A listener asked, why does Venus have such a thick atmosphere when it has no magnetic field? The lack of a magnetic field at Venus exposes its atmosphere to the damaging effects of the solar wind. High-energy particles break up atmospheric molecules into charged ions

that can be picked up by the charged solar wind and are then blown off the planet. When water is broken up into hydrogen and oxygen ions, the lightweight hydrogen is quickly whisked away. The presence of a magnetosphere at Earth has protected our atmosphere from this process, but Mars and Venus are both exposed to the full force of the solar wind and have lost most of their water to atmospheric escape. They have been left with skies of carbon dioxide, which is made of heavier elements that are not so easy to blow away. The atmospheric pressure on Mars is less than 1% of Earth's, but Venus still has an atmosphere with a surface pressure 90 times Earth's.

How can it have so much air? Stay tuned to Planetary Radio to find out. You regulars remember Andrew Westfall, right? Wow, there it goes! Whoa! Hey, hey, hey, hey, hey! Oh, my God, it's spectacular! That was Andrew last January, reacting to the Stardust sample return capsule turned fireball

as it headed toward a desert touchdown. We're checking in with Andrew periodically as Stardust begins to release its secrets. The UC Berkeley Space Science Laboratory researcher is also getting ready to turn on the Stardust at Home project. You may be one of those who is already registered to help find infinitesimal bits of interstellar matter collected by the spacecraft. After some online training, participants will be sent an image

scanned from the Stardust collector. If all goes well, John or Joan Q. Public may very well be the first human to see a confirmed piece of matter from beyond our solar system. Andrew, you've been filling us in on the Stardust mission ever since it streaked past you in the sky on re-entry, and we thought it was time to check in again because you guys are finding some pretty amazing results from that great spacecraft. Yeah, we are. It's really exciting.

We announced about a month ago at the Lunar and Planetary Science Conference in Houston that some kinds of minerals that were really completely unexpected have been found in the cometary material that was collected at the comet VIL-2. These kinds of minerals are very high temperature minerals, kinds of materials that only form at thousands of degrees. And the surprise is that this stuff was collected from material which formed out in the outer solar system where it's been, as far as we thought, cold ever since the formation of the solar system where it's been far as we thought cold ever since the formation of the solar system so this was really quite a surprise we're still puzzling about this and it may take years in fact to figure out what in

fact is really going on so are there any guesses yet that anyone can share about how these and or where these might have formed well there are several ideas one of them is theory that was actually proposed several years ago by Frank Hsu, who was at that time at Berkeley, and his colleagues, including Matthew Gunnell. It's called the X-WIND model, and it's the idea that as we see in solar systems that are forming right now that we can look at in telescopes. There are jets that are formed, bipolar jets. It means jets that come out of the north pole, north axis and the south axis of the sun. It's not coming out of the sun, but they're coming out in that direction. These things may be

cycling material, kind of like a conveyor belt from the middle solar system and then throwing stuff out of the solar system and also out into the Kuiper Belt. So that may be how this is happening. But there are a lot of puzzles. You know, none of these pictures are complete. And almost every theory that you propose or that has been proposed, you can poke holes in one way or another.

So it's clear that the situation is not simple. But there's no reason why it should be. And so it's going to be a lot of fun to figure all of this out. It really is fascinating, and I had not heard that theory. The first image that I got was of a pitching machine, an interplanetary pitching machine, like you'd see in a batting cage. We should remind our listeners that Stardust is really a two-faceted or two-sided mission. The cometary particle side of this, your colleague, Don Brownlee,

was describing some of the material recovered as rocks because they're so much bigger than was expected. That's absolutely right. They're much bigger. The individual components of the particles that were collected are much larger than we expected. That's right. Don called them rocks, and that's really what they are. And that's posing some interesting challenges for analysis. We have to figure out now how to really effectively carve up these hard rocks to distribute them to people.

We're doing so now, and that's working out pretty well. But we still have some challenges ahead of us to figure out how to do it really right. So it's fun. You know, we don't look at it as a problem. We look at it as a challenge because it really is. It's really fun, genuinely fun to work on these things. So this is another surprise.

You thought you knew roughly what you'd be getting back, and you had planned to work with these samples based on them being quite a bit smaller. That's right. One of the principal tools that's used for preparing samples for analysis is called ultramicrotomy, in which you use a diamond knife to carve these small particles into little slices, very, very thin slices, only a few hundred or even 100 nanometers thick. It turns out that that works very well on very fine-grained materials, but doesn't work as well for these big, hard minerals.

And it also dulls your diamond knife really quickly. That must be expensive. It is, actually. So there are other techniques that people are now using, including a relatively new technique called focus ion beam milling, FIB is what it's called. And my colleagues at Livermore National Lab, Giles Graham, and Naval Research Lab, Rhonda Stroud, are using these tools now to slice these particles up. It's a really impressive technique, and it's just, you know, another example of the advantage of doing sample return missions, that is that you can apply techniques to these samples that couldn't have even been imagined when the mission was conceived, let alone launched.

And that's true in many ways. There are many techniques now that have come online since the Stardust mission was launched that are adding hugely to the analytical capabilities of the community, and it's just great. So this was actually, these are techniques which will be useful for projects that are very much Earth-based. Yes, that's right. That's right. One example of this is an instrument called the nanosims. This is an instrument that can measure isotopic abundances of materials and make maps on incredibly tiny scales. This is a new instrument.

Now there are a handful of them in the world, but at the time that Stardust was launched, there were zero. And it's a wonderful instrument for doing this kind of work. What did you say that instrument was called again? It's called the NanoSIMS, N-A-N-O-S-I-M-S. Let's turn to, quite literally, the other side of this collector, the side that was out there to collect Stardust, and this project, which I guess, as we speak,

you are in the middle of a dry run of the Stardust at Home effort. That's right. Stardust is really two missions in one. One, the one we've been focusing on in the last few months, ever since recovery, has been the cometary collection. But the Stardust Collector is actually two-sided. And one side collected comet dust. The other side collected interstellar dust that is continuously streaming into the solar system.

At least we think it did. The reason I say we think is that only a few days after recovery, the collectors were taken apart and the interstellar collector was put in a cabinet, and essentially nobody has looked at it since. That's not true. That was true as of about two weeks ago. My colleague Anna Butterworth spent a week down in Houston, week before last, and she was getting our automated microscope ready to scan this collector. So that's now all set up, and we started scanning. We're really excited. And we now for the first time have actual images of the interstellar collector. We're having to learn how to deal with this particular collector though, because as with the commentary side, things aren't

quite as we expected. It's turning out to be a little bit of a challenge again to figure out how to scan this thing in the best way. And so we've been spending a few days learning how to do that. But I was just looking at some of the images that were collected on Friday, and they just look great. So I think we're in great shape, and we're going to start collecting for real this coming week. We'll have more from Stardust scientist Andrew Westfall when Planetary Radio returns in a minute.

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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. Welcome back to Planetary Radio. We're talking with Andrew Westfall of the UC Berkeley Space Science Lab. Andrew was just telling us about the successful dry run of the Stardust at Home project, but he wants to assure everyone that no one has begun looking for bits of interstellar matter just yet. We don't want to get any kind of head start on searching for interstellar dust with this collector.

And so as we look at these images, all we're doing is just looking at them to see that they're in focus, that the brightness is about right, and that that's what, that they're good to go for searching. But we really don't want to, even though it's so tempting and we're just chomping at the bit, we deliberately do not do any searching. So we're waiting until we actually launch the Stardust at Home project before we actually search for any grains, because we don't want to get a head start. I think that would be unfair.

Well, that's very decent of you. And what it means is that these people who are signing up all over the world to participate in Stardust at Home, because you are pre-registering people, I guess, really will be, if they happen to find these particles, they will be the first eyes to see them. That's exactly right. That's exactly right. So as you said, we are now doing a load test of the system. We were overwhelmed with the response to this project, and at first, frankly, we panicked. Because we realized very quickly that the data pipe at UC Berkeley would be completely inadequate to handle the traffic that would be required to serve the data to the volunteers who've signed up. on storage, had just come online, and they volunteered to donate time to us, or storage,

I should say, and data handling capacity. We heaved a huge sigh of relief, and since then, we've implemented that approach. So what we're doing right now, in fact, is we've asked members of the Planetary Society to help us to do a load test on the system to make sure that we can handle many thousands of people working all at once on the search for interstellar dust. And that's going very well. I was just a little bit ago, I was doing some testing myself just on the virtual microscope that we use. It seems to be working just as fast as it usually does. So we're really quite encouraged.

It's a little preliminary. We need to actually look at the data after the load test is over and see how it goes. But we're very, very grateful to members of the Planetary Society who are helping us out to do this. I think it's a really exciting project. So this is sort of a scalability test, but how many people have signed up for Stardust at Home when it really gets underway, which I guess is going to be in mid-May? We think it's going to be mid-May, yeah. That's our current target date. Now, that may change

as we go. We're learning. There's a wonderful quote that's attributed to Einstein. If we knew what we were doing, it wouldn't be called research. And that's really true. We're just learning how to do this ourselves. And as we go, we're learning. And we just want to make sure that when we actually do start that we really have it working well. So we're not going to start until we're really ready. But I do want to assure the listeners that nobody's going to be getting a head start on looking for these grains. And in fact, the load test that we're doing right now is not on any data from the actual collector. It's from data that was collected either on the Russian space station meter, or it was data that we collected from aerogel tiles that were shot at a dust accelerator in a terrestrial laboratory,

actually at the University of Heidelberg. So nobody has yet looked at any of the actual stardust interstellar tiles. It's almost as if it's an interstellar land rush and you're going to fire a gun and people will jump in. Well, we'll see what happens. Yeah, that's what we think might happen. How many, what are you measuring, in the tens of thousands, people who've signed up? We're now over 113,000 people who pre-registered. It was quite a shock.

Well, we'll look forward to that in the middle of May. I should mention also that right now on our website, planetary.org, my colleague Amir Alexander, who's been following the project, has a great piece that starts with a busy day for your colleague, Anna Butterworth, of UC Berkeley, doing exactly what you were talking about, starting that scanning of the interstellar matter on the Stardust Collector. Now, I guess we're talking to you. You're at home now at UC Berkeley.

Have you been shuttling back and forth between there and Johnson Space Center? Yeah, we've been spending a lot of time in Houston getting this thing going and also working on the commentary samples. So it's almost become a home away from home. I'm back here in Berkeley and probably will be for a while now. And how long do you think this is going to keep up? How long will we be learning directly from these samples returned by Stardust? For years? Oh, I think for years, if not for decades. Yeah. I mean,

this is another huge advantage of sample return missions is that you bring back a sample and you can study it for years. That's still true, for example, of the materials that came back from the moon. I remember you saying that. yeah. That's right, yeah. And what's amazing, actually, to me, is that only about 10%, I think less than 10%, of the lunar materials have ever been studied in any real detail, and most of them have not been. And I think that that's actually a good thing, because it'll be a resource for scientists for many, many years.

Of course, we may be going back to the moon soon, and we'll get more of them. Nevertheless, these samples are unique, and I think they'll still be an incredible resource. And that's certainly going to be true for startup samples as well. It also allows us, of course, to take advantage of instruments that may be developed by our grandchildren. So who knows? If you look at the difference between the kinds of instruments we use now and the kinds of instruments that were available two generations ago, and you extrapolate that into the future, boy, it's mind-boggling.

Andrew, we're out of time. Another question just occurred to me that I have to ask. If you could get a few grams of material back from anywhere else in the solar system now, where would you look next? Oh, that's a great question. Well, I guess I'd have to say that it would be fascinating to get a sample of ice from Europa, because it's a fascinating object, and who knows, it might even harbor life. Great answer. Maybe you'll get to participate in that project someday.

I hope it happens, certainly, in our lifetimes. Yes. Andrew, thank you so much for joining us again with this update on Stardust, and I'm sure that we're going to want to check back with you again, particularly as Stardust at Home gets underway and you start getting results back from those over 100,000 observers around the world. Well, we're really excited about it, and we are really grateful to all the people who've volunteered to help. Andrew Westfall is at the UC Berkeley Space Science Laboratory, and as you've heard, working on the samples returned by the Stardust mission that

came back to Earth after a very long journey just last January, and we will check in with him again. We'll be checking in with Emily Lakdawalla for the conclusion of this week's Q&A segment in just a moment. And after that, Bruce Betts will be here with What's Up and a new chance to win a Planetary Radio t-shirt. I'm Emily Lakdawalla back with Q&A. How can Venus's atmosphere be so thick if the solar wind has blown all of its water away? Venus is usually compared to Earth because the two planets are very similar in size and presumably formed from just about the same materials. But while their bulk compositions are the same,

Venus and Earth store some important materials in very different places. The surface of Earth is covered with a thin layer of liquid water and also in many places by deposits of rocks and soils made of carbonate minerals. Carbonates sequester huge quantities of carbon and oxygen, the elements that compose carbon dioxide, in solid form. Plus, Earth has a biosphere made almost entirely of these light elements. Venus has no oceans or life and may not even have carbonate minerals in its rocks. It appears that every last bit of its carbon and oxygen is up in its air.

its carbon and oxygen is up in its air. If you think about how much of Earth is covered by limestone, clay, and mud, you realize just how much of these light elements Venus had to begin with. It's still got a lot left to lose. 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 have Bruce Betts on the line, and he is in his car like any good Southern Californian. He is, well, what freeway are you on? 134. 210 to 134. I don't know. Try 134. But you do know where you're going.

I hope so. Hey, what's up? Hey, the night sky and planets. And Jupiter, Jupiter's cool. Jupiter's in opposition on May 4th. And so that means that it is rising around sunset and setting around sunrise. It's a really, really bright thing in the early evening sky that you will see off in the east. And then you will see it off in the west looking very bright in the predawn sky, while simultaneously Venus is looking even brighter in the opposite side of the sky over there in the east. And so those are the two really bright ones. We also have Mars and Saturn still hanging out fairly low in the west now

and fairly close together. Mars, of course, kind of reddish, and Saturn kind of yellowish, and hanging out, having fun in the sky, but being quite outshone by Jupiter these days. So they're hanging out over in the western sky, so the opposite side of the sky from Jupiter. That's your planet roundup. Get ready.

In a few weeks, we have Mercury coming back to the evening sky. So are you going to go look, Matt? Yeah. Yeah, I think I will, actually. Can you give us a traffic report while you're at it? Yes. We're cruising along at here about 55 miles per hour. Well, there's a sig alert on Mars, and we've got traffic stops all over Venus,

and a lot of cars breaking down due to the heat. But other than that, we move on to random feedback. I want you to do that out the window of the car. No, go ahead. Please, that'll do just fine. We want you to be around for next week. It's hard enough for me to keep from hanging my head out the window when I'm driving anyway. There's so many smells.

That's the canine in you. So many smells. Anyway, randomly in our space facts, we're deep within the sun. Did you know, Matt, that it takes, on average, 170,000 years for a photon created in the core of the sun to make it out to what is called the convective zone? And it's still not out of there. But then things really bog down.

So they kind of do random walk processes on the way back. Basically, the sun's really, really big, and there's a lot of stuff in it. So the photons that are making it out to the surface were created way long ago. I have heard that figure. I didn't remember it was quite that long, but it seems just amazing that these little particles of light would be trapped in there for so long. But there you go. It's a swell universe.

Trapped like rats, I say. Rats, rats. It reminds me of a story at the Planetary Society, but we won't go into that right now. Okay, let's move on to the trivia contest, shall we? We asked you about the Hayabusa spacecraft, which was very successful at going up to an asteroid. It was supposed to be a sample return. They may still be able to recover it. The question was, where was it intended to return its sample to on Earth? How did we do that?

Lots of entries, as usual. We got an interesting one from Brent Livingood, otherwise known as The Rev, around here. He enters regularly. He didn't win this time, but he did send this really cool photo of the football club, Reed Soccer Club, in the town near where Hayabusa's return capsule is supposed to come down. And I do love the town name. Woomera. Woomera. Woomera in the Australian outback.

And here is a picture. It's not just the Woomera Football Club, Bruce. They are in drag. And he says, yes, this is really it. And there's a big happy birthday sign behind them. I have no idea what this has to do with returning samples from Hayabusa. But our winner this week is Dragos Mitsrika. Dragos Mitsrika from Brasov, Romania, of all places.

Excellent. Dragos got it right. He also said it's coming down in the Australian outback. Good on you, mate. Did you pull off the freeway? It's gotten very quiet there. It has. It's pulled off the freeway and everything.

But the freeway's still looking good for those of you out there. Well, I'm glad to hear that you made it in one piece. We always worry about that in Southern California. And now you can tell us about next week's contest. Okay. For next week's contest, we'll go with a discoverer question. Who discovered Neptune? Who discovered Neptune?

Go to planetary.org slash radio and find out how to email us your fabulous answers and compete to once again what, Matt? Win a Planetary Radio t-shirt? Yeah, I think we'll give them another t-shirt. The envy of the Galaxy? You bet. Monday, May 8th is the deadline. Monday, May 8th, 2006 at 2 p.m. Pacific time.

Get your entry in to us now and maybe we'll throw in a ride on the 134 with Bruce. Well, uh, huh. I think we should give people more time for that. That's a pretty big reward. Oh, okay.

Well, we'll make that the grand prize, which is something we have to get around to sometime, having a really swell prize here. But we need to get out of here anyway. We do. We're looking forward to the ISDC conference. Oh, of course. As we speak, it is mere days away, and I'm told over 1,000 people are planning to go to the Sheraton Gateway near LAX, LA International, and the Planetary Society is well represented.

And I'm guessing people are going to hear more after the conference about what happened there. You bet. Our next week's show will definitely be based on things going on at the ISTC. Cool tunes. Well, everybody, hey, go out there, look up at the night sky, and think about what your favorite flower is. Thank you, and good night. He's Bruce Betts. He's the director of projects for the

Planetary Society, and if he's not driving, he always calls shotgun. Next week, we'll bring you special coverage of the International Space Development Conference in Los Angeles, featuring a who's who of space celebrities. Think of it as our version of the red carpet

outside the Academy Awards. There's more coverage of the ISDC at planetary.org. Planetary Radio is produced by the Planetary Society in Pasadena, California. Have a great week, everyone. Thank you.