Planetary Radio: Space Exploration, Astronomy and Science - Stardust@Home Update from Andrew Westphal

Episode Date: December 3, 2007

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A Stardust at Home update from Andrew Westfall, 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. Are they a few dozen bits of the universe that have traveled light years to reach our solar system? The Stardust team thinks at least some of them are, and with the help of 23,000 pairs of eyes, they are almost ready to find out what they're made of. Andrew Westfall will tell us about the great progress made with the delicate samples returned to Earth by the Stardust spacecraft nearly two years ago.

Emily Lakdawalla will speculate about life on Jupiter's moon Europa, possibly swimming around beneath that distant world's layer of ice. And Bruce Batts will prepare you to enjoy the busy fall night sky with his What's Up report, including a brand new space trivia contest. Let's see, there must be some news to report from somewhere in the galaxy. We haven't heard from our Bureau on the Crab Nebula for simply ages, but we can tell you that NASA has given the go for a December 6 launch of space shuttle Atlantis. Commander Steve Frick and six crewmates will blast off for the International Space Station,

where they will install the European Space Agency's Columbus Laboratory. That's going to require at least three spacewalks. Out on the vast Martian wasteland, Spirit spent a few frightening days mired in dust. The Mars Exploration rover unwittingly rolled into a tiny crater full of the stuff, getting all six wheels stuck. Drivers managed to free the little craft, and it's now back on course for its winter resting place. There's a detailed update on both rovers at planetary.org. And as if that darn planet wasn't already hostile enough, Venus Express

scientists now say second rock has lightning. Add that to the sulfuric acid rain and 800 or so degrees in the shade, which there isn't any of. That story is also at planetary.org. I hope you know you can always get the latest space exploration news from Emily Lakdawalla's blog at yesplanetary.org. Here she is with this week's Q&A. I'll be right back with Andrew Westfall and Stardust at Home. Hi, I'm Emily Lakdawalla with questions and answers.

A listener asked, how could life survive on Europa? The Jupiter system does not seem a very likely place to harbor life. Jupiter orbits more than five times farther from the sun than Earth does. That means the Jupiter system is so cold that the ice on its moons is as hard as rock is on Earth. And it also means that there isn't much solar energy to power either spacecraft or life. There's an additional hazard to life in the Jupiter system caused by Jupiter's powerful magnetic field. There's an additional hazard to life in the Jupiter system caused by Jupiter's powerful magnetic field. The magnetic field ionizes atoms, creating radiation belts full of energetic charged

particles. These energetic particles are incredibly destructive to large molecules, so life based upon large molecules cannot survive without being shielded from the radiation environment. So how could life survive in the frigid, sterilizing environment of the Jupiter system? Stay tuned to Planetary Radio to find out. There's a decent chance you are one of the millions of computer users who is part of the SETI at Home project. There's a much smaller chance you've taken on a greater challenge,

one that relies on the sharp eyes of people around the world to find tiny pieces of our universe trapped in aerogel like fossils in amber. That's the Stardust at Home project for which tens of thousands of participants have been trained and certified. Andrew Westfall joins us now and then to provide an update on this unprecedented effort. He is a senior fellow and associate director of the Space Sciences Laboratory at UC Berkeley. He also heads Stardust at Home. We talked to him between trips to the Johnson Space Center in Houston, Texas, where the aerogel collectors from the Stardust spacecraft have been carefully protected since their fiery return to Earth in January of 2006. Oh, you may remember our first conversation with Andrew as he and his family watched for the nighttime re-entry

of the Stardust return capsule. Oh, wow, there it goes. Whoa! Hey, hey, hey, hey, hey! Oh, my God, it's spectacular! Andrew, welcome back. From what I read, you are making steady progress on those Stardust at Home samples. We are. We're having a lot of fun with this project. We've scanned now about one-third of the interstellar collector on the Stardust spacecraft, of the interstellar collector on the Stardust spacecraft,

and about 23,000 people have done more than 40 million searches on the imagery from that collector. It's just been a tremendous success. In fact, what's really neat about it is that not only are people really, really hardworking, they are also extremely good at it. Many of them are much better at it than we are at this point because they put in so much effort. And we know this, in fact, because we calibrate their, we measure how well they do by using calibration images, images that we already know about. 23,000. You know, it makes me wonder how many of those are also SETI at home participants. But here

you're relying on wetware, human computing. And maybe you can provide a little thumbnail description for the folks who haven't heard you in the past or seen the coverage of Stardust at Home. Yeah, that's exactly right. You know, this was inspired by SETI at Home. And, in fact, the SETI at Home folks are just down the hall from us. But it is fundamentally different from SETI at Home. You know, SETI at Home uses the spare CPU cycles of, it feels like, zillions of computers all over the world. But our project is quite different in the sense that

we rely on the incredible image processing capability of the human brain. The computer is really just kind of incidental to the whole project. It carries what we call a virtual microscope. It's a microscope written in software. It functions just like a real microscope. You can focus up and down through a series of images, just as if you were peering through a real microscope and focusing up and down. It actually works beautifully. This is an idea of Dave Anderson's, who is on the SETI at Home project. People can search these images for the tracks of interstellar dust particles right on their computers anywhere in the world. And in fact, it has happened literally everywhere in the world. I think we

have participants in this project from something like 57 countries. So 23,000 people who've, you know, the preparation for this is not trivial. It's not like just installing a screensaver like SETI at home. They actually have to be trained on your website for what to look for. That's absolutely right. Yeah, this is not something where you can sit back and just watch the action. You have to actively participate. First of all, to participate, you have to take a tutorial, go through a tutorial to understand how to search for these tracks. And then you have to take a test.

And you have to get 8 out of 10 on the test before you can even sign up. But the real work comes in, of course, when you actually start searching. It's just amazing to me how many people have put in hours on it. At least I shouldn't say that, actually, because I find it incredibly fun. And so in some sense, it's really not surprising that people have really had a lot of fun doing a lot of work on this. I imagine that, well, unfortunately, at least so far, unlike SETI at home, people actually do find bits of buried treasure, bits of the universe. That's right. That's right. Now, we don't know for sure. Unfortunately, we've been know for sure. Unfortunately,

we've been forced to collect these images in the worst possible way. We have to image these tracks with the aerogel tiles still in their original collector. And we're forced to use a kind of illumination, which is not the ideal. We won't know for sure about any of these things until we extract them. And we're going to be starting that in just about a month from now. We're going to be starting to extract some of these particles and analyzing them. So we're really excited because these are potentially the very first samples of solid material ever brought back to Earth to study from outside of our solar system. Ah, interstellar. Interstellar dust, that's right, from the local interstellar medium.

There is a great article, homepage of the Planetary Society website, planetary.org, by Amir Alexander, my colleague there, documenting the progress that you've made while you've got these tens of thousands of people finding these little bits of interstellar dust, we hope, where you guys have had to refine your technique for how you're going to get these out of the collector. And there have been some challenges. There sure have. You know, it's an incredibly difficult task because these tracks are only a few microns across. They're incredibly tiny, which means we have to use techniques which are extremely high precision. But the problem is, the challenge is that these tracks cannot be extracted from the aerogel tiles after they've been extracted from the tray. We have to extract them right from the tray, just as we're doing the scanning. And the reason for that is that these tracks actually indicate the trajectory of the particles when they came into the collector. That's an incredibly important piece of information that we have to preserve.

If we pull the aerogel tiles out first, which would make our job easier, it might compromise that information. You know, this is an absolutely unique and precious sample, and we have to be incredibly careful with it. If anybody dropped it on the floor or anything like that to compromise it, it would cost more than $200 million to get a new one. So we have to be unbelievably careful. And you've been learning how to do maybe not microsurgery but picosurgery on these samples. That's right, yeah.

So we've developed a technique which is sort of an extension of the same technique we use to pull cometary particles out of the cometary stardust collector. The other side of the collector of stardust. Of that same collector. We've been refining and extending this technique to be able to do this on the interstellar tray. And it involves putting out an arm out over the tray, which could reach all the way across the tray. The tray is about the size of a stop sign. So that's a long way to go when you're talking about micron precision. But now we know how to do it, and we're ready to go. And there are photos of some of this equipment with this big, pretty hefty-looking optical microscope, I guess,

that you guys are using to do these fine movements. Yeah, that's right. That's right. We've developed some special hardware to be able to hold the tray onto our microscope. It's, in fact, the same microscope that we use for scanning for artists at home. So it's doing double duty. I'm looking at the picture of your vibration isolation table, which looks like it's wrapped in tinfoil. Yeah, that's right, you know, because it's in a clean environment. We wrap everything carefully to keep any dust from getting onto the collector. That's Andrew Westfall, director of the Stardust at Home Project. He'll be back with me in just a minute. This is Planetary

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The Planetary Society, exploring new worlds. Welcome back to Planetary Radio. I'm Matt Kaplan. My guest is UC Berkeley's Andrew Westphal, director of the Stardust at Home Project, for which volunteers around the world are finding what may be matter from other stars returned to Earth two years ago by the Stardust spacecraft. Andrew and his team are almost ready to begin removing these micron-sized bits from the aerogel collector that trapped them. Now, I think you said that so far you've been perfecting this technique on, well, really dummy pieces from the collector, but now you are ready, what, this month to start digging in for the real samples? Yeah, right after the new year, we're going to be working on the actual flight tray. This has been a little bit of a hiatus because the work is being done on the cosmic dust Dust Lab at Johnson Space

Center. And that lab has to do double duty. It is not only housing the interstellar collector for Stardust, but it also is the processing facility for interplanetary dust particles that are captured in the stratosphere. So the last few months, they've been processing a backlog of requests from the community for these interplanetary dust particles. But that's been not a bad thing for us because it means that we've had a good possibility or a good opportunity to refine our techniques on the flight spare tray, which can be out at the same time as the interplanetary dust particles. Can you quantify the number of sample candidates, particle candidates, that you have to dig out now of this collector tray?

We have several dozen that we're really excited about that we think are interesting enough to expend the effort, which is considerable, to pull out of the tray and examine. And that's going to take quite some time because it's a really quite painstaking process. There are some other interesting features that we've found and that, well, I shouldn't say we, I should really say the so-called dusters who are participating in Stardust at Home.

Many interesting features that we don't understand, that we are really going to be interested in extracting and analyzing. We don't know what they are, but of course this is entirely what makes this fun, finding the unexpected. A few dozen of these is still not going to amount to very much in the aggregate. Will you be able to analyze these, put them in a spectrometer, and figure out what they're made of? Right, we will, and that's because of the incredible advances in analytical techniques over the last several years,

some of which have actually been inspired by the Stardust mission itself. In fact, this is a bit like the Apollo days. You know, when the Apollo days. You know, when the Apollo samples came back, that inspired the development of all kinds of new techniques for analyzing these precious samples. In fact, we're standing on the shoulders, you might say, of the giants who developed these techniques 30 or 40 years ago. And now we have amazing instruments. For example, there are going to be several synchrotrons, including one here in Berkeley called the Advanced Light Source, but also others, one in Europe and one in Chicago and one at Brookhaven National Lab.

And these are going to be used to analyze these samples non-destructively. Basically particle accelerators. They're basically particle accelerators. And really what they are are X-ray microscopes the size of a shopping mall. Oh. It's to do X-ray spectroscopy. So there are all kinds of different techniques that you can use here, but the principal ones are something called X-ray fluorescence.

I didn't want to let that just fly by. X-ray machines the size of a shopping mall. fluorescence. I didn't want to let that just fly by. X-ray machine's the size of a shopping mall. Listen, you were telling me that you've got other interest in the very technique that you have used using these human computers, human abilities to process images. You've been getting calls from other researchers. We have, actually, and that's been also very exciting and very gratifying. Let me just mention one project that I think is really exciting and fun. It's working with a paleontologist at Berkeley named Tim White, who is a specialist in ancient hominids. He goes every year to Ethiopia and searches for ancient fossil hominids by walking across the landscape after the rainy season

and looking for fossils which have been uncovered by the rains. And we're hoping that we'll be able to use this kind of approach to search imagery on the ground for ancient fossil hominids and cover much, much more ground than they could do in practice using the old-fashioned way of doing it, which is just walking across the landscape. And so almost a direct parallel to your colleagues there down the hall at Berkeley in SETI at Home, where people saw this technique using computers and have applied it to other research. Now, human eyes moving beyond Stardust at Home. Yes, that's exactly right.

Yeah, I think that's right. It's a parallel development. SETI at Home inspired all kinds of new and exciting ways of applying distributed computing to problems. So this approach of using the human brain and thousands of human brains to do things that computers really are not very good at to other projects, I think, is really exciting. Ain't science grand? Yeah. Listen, we're almost out of time. Is it too late for more people to get in on Stardust at Home?

Absolutely not. In fact, people are signing up all the time. And we're right in the middle right now of what we call Phase 2 of Stardust at Home, in which we have posted images of the original first third, but at higher resolution and higher magnification than people had been looking before. at higher resolution and higher magnification than people had been looking before. And we've also made it a bit harder to find the calibration events. And that's just because people were so good at it in Phase 1.

They were so good that we couldn't even measure how good they were. Now we're using these higher resolution images to search for even finer features. So this is advanced class. Do you have that URL on you? We will put it up at planetary.org, of course, where we have a whole section on Stardust at Home. Yes, indeed. It's stardustathome.ssl.berkeley.edu. Excellent. Okay. Andrew, we're out of time let's uh check back with you once more uh when uh you start to dig those guys out and see what they're made of yes very good i look forward to that thank you so much thank you matt andrew westfall of the stardust mission that has of course returned comet bits and maybe our first, we hope to prove, first bits of interstellar matter

sitting right now at the Johnson Space Center where Andrew and his colleagues and 23,000 people around the world and counting are finding them and helping us to figure out where they came from. He is a senior fellow and associate director of the Space Sciences Laboratory at the University of California at Berkeley. We're going to be right back with Bruce Betts for this week's helping of What's Up. That'll be after a return visit by Emily. I'm Emily Lakdawalla, back with Q&A. How could life possibly survive at Jupiter's moon Europa? Earth-like life would need a source of raw materials, including both light and heavy elements,

water to act as a medium for chemical reactions, a source of energy to power those chemical reactions, and protection from Jupiter's magnetic field. These conditions don't exist at the surface of any of Jupiter's moons, but Europa very likely has a liquid ocean buried within it. The floor of that ocean is very likely the rock of Europa's core, providing the necessary raw materials. The thick icy lid of that ocean would shield it from Jupiter's radiation.

Most importantly, the youthfulness of Europa's icy surface indicates that Europa has been geologically active very recently, meaning that there is a potent internal heat engine. Europa's ocean basins almost certainly have some kind of geology reminiscent of the deep-sea hydrothermal vents on Earth, which are absolutely teeming with life. Unfortunately, it may prove difficult to discover Europ in life if it exists. The protective icy lid over its oceans will be very difficult to tunnel through, and if we do send an Earth-built robot down there, we risk contaminating Europa's oceans with stowaway bacteria. For the near future, the best we can do is to sample Europa's surface in a place where

material may have been brought up from depth and search for chemical byproducts of Earth-like life. 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 the first post-fifth anniversary What's Up with Bruce Betts, the director of projects for the Planetary Society. You know, it's a little bit of a letdown, but we had such a good time doing that contest, and so many people wrote in and entered,

but also said nice things about the show. Kind of anticlimactic. A little bit. But I'm looking forward to the next five years. We got to start working on the next prize. This is the first step in the next set of shows that leads to the rest of our lives. Yeah, you should write that down.

Put it on a poster. Oh, I will. It's like a cat dangling from a tree. Hey, good there. Okay, on to the... What's up? What's up? Meteor shower, Geminid meteor shower, best meteor shower of the year, traditionally, with about 60 to even 100 meteors per hour at its peak on December 14th. You can also check it out a couple days before, a couple days after. Go out, just stare up at the night sky. Better later in the evening.

Watch meteors and relax. And we also still have Comet Holmes. Comet Holmes actually started to get a little trickier to see, at least naked eye. But now it's looking better, and the moon's out of the picture for a few days here. So it's a darker sky. It's also moved away from our friend that we'll talk about in the trivia contest, Murfak. It was pretty much in front of Murfak, and now it's off a little farther away from the glare. And then in the pre-dawn sky, we've got the very bright Venus in the east,

brightest star-like object in the sky. Up above that is Saturn, pretty high overhead. And then still up is Mars, but Mars you can now check out in the early evening. In the east, it is the bright red thing. It is about as bright as the brightest star in the sky right now. It will continue to get a little bit brighter through the end of December. If you have a small telescope, you might be able to check out a polar cap or some objects, certainly with a larger telescope you can.

Good time to see Mars. Not nearly as bright as it was two years or even better four years ago, but still very bright. Good opposition coming up. And that's kind of the rundown. Although if you've with that telescope also or binoculars, you can still check out Uranus and Neptune in the evening sky. So for them and for the comet, comets in Perseus near Murfak, but you can also check out finder charts online at a number of sites to find those. On to this week in space history. 1973, first flyby ever of a spacecraft of Jupiter. That was Pioneer 10.

A year before, last launch to the moon, Apollo 17. And 1998, nine years ago, Unity and Zarya modules were connected, forming the core of the International Space Station that they continue to create lovely add-ons to. Nine years ago. Nine years ago. Isn't that amazing? That really is. Yeah.

That's why I brought that one up. On to random space fact. Speaking of space stations, I have some strange fascination with skylab breakup random space facts and i've got another one for you skylab of course uh u.s space station came crashing down to earth in 1979 spread some chunks around australia well in kind of a freak of timing it happened to do that just a few days before the uh the miss universe contest was held in perth australia and they displayed a big chunk of it on the stage. Are you serious?

In fact, it was the first runner-up. Had the winner not been able to fulfill their duties... Miss Congeniality. Skylab would have... Yes. Not so much. Not after it came raining down in Australia. I was going to say, you know, if it was a small enough piece, they could have used it

as the crown for Miss Universe. There she is. It could have continued. How the crown for Miss Universe. There she is. How appropriate. That would have been cool. Next time. Next time. Yeah. When the ISS. Oh, no. We don't want to go there.

All right. On to the trivia contest. We asked you about our friend Murphak. Murphak, the brightest star in Perseus. It is just a little bit below Comet Holmes. And I asked you, since we had silly adolescent humor about, what a funny name, Murphak, where did it come from? And where did that name come from and what does it mean?

How did we do? We got so many entertaining answers to this. My favorite, he actually had the right answer too, but it came from Andrew Boyle. He said it means to make Matt laugh. That is correct. No, it's actually not very correct, but we did get all kinds of people who got it right. Tom O'Reilly from the Monterey Bay Aquarium Research Institute, he was also pretty cute. He talked about, first of all, he gave the actual meaning. And the complete phrase is al-mrifak al-thariya, meaning elbow of the Pleiades.

Oh, elbow. Elbow. Oh, I thought it was armpit. Well, you're close. You're very close. Oh, okay. Apparently wrong translation. And in need of an antiperspirant. Yes, definitely. And that's from Arabic, right? Yes, it is. In fact, he actually puts the Arabic here. I don't know where he got that character set.

And then he mentions it's often confused with mirak, which means loincloth. He said this alliteration led to the famous Arabic insult. And he has another line in Arabic, which translates as, that guy can't tell his loincloth from his elbow. Wow, we learned so much on this show from our listeners. And how. And then there's Torsten Zimmer. He came up with other funny names of stars, and I don't know if these are put on or not.

He says there's one that had translate as the tripods for cooking on Sigma, and another, the fatty tail of a sheep. He says, but my favorite though is Kokab, which simply means the star. You sure these aren't translations, like from subtitles? Bad subtitling? I think they're translations from Torsten's imagination, actually, myself. But you know who won?

Ilya Schwartz. Ilya Schwartz, a past winner, won something like a year and a half ago. Ilya got it. Sure enough, elbow of the Pleiades, and we're going to send him a T-shirt. Indeed. And it's not all that far from the Pleiades, by the way. Okay, let's give you a new trivia question. Give you something easy so people can complain it was too easy.

But hopefully more people will enter. Who, what person, had the longest gap between their space flights longest time period between two space flights who was that oh i know who it has to be incredible isn't it yeah joseph stalin oh i gave away the answer no that is incorrect go to planetary.org slash radio find out how to enter and you're going to need to get that to us by the 10th of December, Monday, December 10 at 2 p.m. Pacific time. We're done. All right, everybody, go out there, look up the night sky, and think about that cool spray paint that makes things look like granite.

Thank you. Good night. I've got to get a can of that. That would be the perfect thing for our house. He's Bruce Betts, the director of Projects for the Planetary Society. He's got concern about all kinds of rocks in the sky and coming out of the can right here on What's Up. Planetary Radio is produced by the Planetary Society in Pasadena, California. See you next week. Thank you.