Planetary Radio: Space Exploration, Astronomy and Science - Stardust-NExT Encounters Comet Tempel 1

Episode Date: February 28, 2011

Jessica Sunshine returns to talk about the flyby of comet Tempel 1 by Stardust-NExT. She is joined by Emily Lakdawalla and Mat Kaplan.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Stardust swings by another comet this week on Planetary Radio. Welcome to Public Radio's travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. It was just a few months ago that planetary scientist Jessica Sunshine joined us to talk about the last comet encounter by a spacecraft. Now she's back with the story of yet another, the Stardust next mission's flyby of Comet Temple 1 on Valentine's Day, February 14. What a cosmic dance this has been. I'll explain why in a few minutes. Joining me in conversation with Jessica will be our own Emily Lakdawalla.

That's why we won't be hearing Emily's usual Planetary Society blog update this week. We will hear from Bruce Betts, though. The Society's Director of Projects will provide his usual rundown of the way up. And we've got yet another space trivia contest for you with a very cool new prize. We'll go now to a special report from Bill Nye. The Executive Director of the Planetary Society was at the Kennedy Space Center on the 24th of February. It was a beautiful day to launch a space shuttle, and that's exactly what happened. Of course, I wish it had happened

last November when I was on the Cape for several aborted countdowns. You know that I'm incredibly envious because there you were watching the launch that should have been mine. You did a great job with it. This is Shuttle Transport System STS-133, launched last week and was spectacular. I happened to be in Orlando, Florida for National Engineers Week, which Disney and Underwriters Laboratories helped sponsor. It was big fun. I got the crowd excited about becoming engineers, I hope. But then we went out, I went out to the launch pad and I got credentials through CNN. It was great. We did a couple bits. the launch pad and I got credentials through CNN. It was great. We did a couple bits. John and I, the CNN guy, did a couple bits about spaceflight and the future. And, you know, the big thing at NASA, Matt, is what is the future of human spaceflight? And even if you're not a resident

of the United States, even if you're not a citizen of the U.S., this affects you because NASA spends more money than anybody else in space exploration. And so all of space exploration sort of looks to the National Aeronautical and Space Administration, NASA, for guidance or leadership or what have you. And now they're going to have, NASA's going to have no way for humans to get to the International Space Station on U.S.-made rockets. I, myself, I'm fine with that. Time to move on. But these are big deal launches if you've got a chance. There's two more. The ground shakes, your chest shakes. Everybody just looks at it as the most spectacular thing because when they're big, heavy rockets like this carrying a 737 worth of cargo into space, they move off the launch pad, if I can use the term, slowly.

They go much more slowly than lighter-weight rockets. And so it's spectacular. It was spectacular even in the little YouTube video. But boy, I'd have given anything to be there. And I guess we would have even more reason to be there next time because the Planetary Society will have a little tiny piece of that cargo space? Absolutely, yes. The Living Interplanetary Flight Experiment. This is a mission that we're going to send to the moon of Mars, Phobos, with some freeze-dried living things on it. And we'll see, we will test the hypothesis. Can you, if you're a living thing, make the trip from Mars to the Earth without

getting cooked by radiation or cold, for example. So in order to fly anything in space, Matt, you have to already have it flown. Wait a second. That's right. It's good to have something, to have your item, your experiment, have some flight heritage. So on Shuttle Launch 134, which is scheduled right now for April 19th, we will get some flight heritage on our Living Interplanetary Flight Experiment, and we'll have some bacteria. We hope to have the arsenate bacteria. These would be the astrobiologically fascinating organisms that seem to have replaced their phosphorus with arsenic, just like in that Star Trek episode where the Horta replaces its carbon with silicon. And we will have the water bears, the happy little tardigrades, which if you look at them

with the right microscopy, seem to be like little bears. So I was there for Shuttle 133. Everything shakes. And the rocket, this huge thing, gets up into space. And it was delayed. And there was a concern it wasn't going to launch within three seconds because the downrange computer, keeping track of the thing to make sure that it stays on course, if it gets too far off course, they jettison the shuttle and they blow the thing up. It's quite a risky business, this rocket flight. It's very exciting. I hope to see all of you down there for 134 in April as the Planetary Society gets some flight heritage on our living interplanetary flight experiment.

Matt, thank you for including me in the broadcast. I'll talk to you next week. I've got to fly. Bill Nye, the planetary guy. And he's the executive director of the Planetary Society, and he will be back next week with his regular commentary. I'll be back in just a few moments with Jessica Sunshine and Emily Laktawalla, too,

to talk about the Temple One flyby just completed by Stardust next. by Stardust Next. Many of you probably heard my conversation with Emily Lakdawalla on last week's show. The Planetary Society Science and Technology Coordinator told us about her conversation with Stardust Next co-investigator Jessica Sunshine. They talked right after that spacecraft encountered Comet Tempel 1 on February 14. Does the name Tempel 1 ring any bells?

It should. This is the comet that another spacecraft, called Deep Impact, zapped with a copper projectile back in 2005. Bear with me here, because it gets complicated. Jessica was the Deep Impact Deputy Principal Investigator, which later morphed into a dual mission called EPOXI. That's a fairly tortured acronym for Extrasolar Planet Observation and Characterization, and the Deep Impact Extended Investigation. Deep Impact EPOXI flew by Comet VILD-2 last November, and Jessica joined us

to talk about that spectacular encounter. Elsewhere in the solar system, Stardust Next was already headed toward Temple 1, Deep Impact's old target. So, long story short, Stardust gave us a second look at this big comet, and even caught sight of the crater left by that impactor six years ago. Jessica and I recently connected via Skype for a conversation about this latest comet to be visited by one of our robots. Jessica, it hasn't been all that long since you were last on Planetary Radio, just last fall that we were talking about deep impact epoxy, and here we are ready to talk about another spectacular comet flyby. Yeah, it's an embarrassment of riches.

It's been a great couple of months for cometary science. I'll say. And I'm sure we will get full agreement from the third participant in our call. And that is Emily Lakdawalla, who most of us know as the person that we talk to about the Planetary Society blog every week. as the person that we talk to about the Planetary Society blog every week. Of course, she carefully follows these things and had a recent blog entry with sort of early science thoughts, observations. Is that a fair characterization, Emily? I guess it's a fair characterization.

You know, I always have fun coming up to scientists after these encounters and trying to poke at them for their early speculations. And, you know, people are circumspect about trying to say too much about what they saw in the images. But it's always great fun to get those first impressions and the excitement right after an encounter. Bill Berkey, who was just on last week, I tried to get him the previous time he was on to tell me, OK, so how many planets did you discover? But he was a good scientist, didn't tell us. So, Jessica, we won't force you to go out on too many limbs here, but it's safe to say that this was a pretty successful flyby.

Yes, wildly successful and really reached beyond all our expectations. Yeah. Emily? Well, you know, I was really struck by the juxtaposition of the Hartley 2 and the Temple 1 flybys. Hartley 2 is a very small, extremely active comet, and Temple 1 is a much bigger and much less active one. And I was wondering, you know, if you could kind of compare and contrast the two comets since the encounters were so close to each other. Well, you're right. They are very different comets.

Well, you're right. They are very different comets, and in fact, it's almost one of the science goals of the Deep Impact flyby of Hartley 2 was to compare it to Temple 1. We just got to compare it twice because we had the old data from 2005 and the new stuff, which is amazing. Temple 1 is much bigger. There's a lot more geomorphology going on. There's more variations in the terrain, largely because, I assume, because it's bigger. It is, of course, producing gas, mostly water and CO2, but at a much slower rate, given its size, than Hartley 2.

And what we saw at Hartley 2 was almost everything we observed was about the, or had some effect from the outgassing. And perhaps the biggest difference is that we found pieces of the comet at Hartley 2 outside the comet, actually in the coma, these ice grains. And I can tell you that we looked with the very same instruments at Temple 1 for these materials and didn't find anything like that in its coma. didn't find anything like that in its coma. And so we're in a very fortunate state now where we're able to go and look at these two different comets in two different states

and try to understand how comets really evolve. And where Stardust is remarkable in helping us here is that we've been able to see Tempel 1 twice now, basically one comet year, one trip around the solar system apart, five and a half of our years. And what we've observed is that there are changes on the surface. There are places that are not the same as they were, where material has clearly disappeared over that year, but that most of the surface, at least to a first order, seems to be pretty much the same. But that most of the surface, at least to a first order, seems to be pretty much the same.

So all that material that we're seeing coming out of it is certainly not coming out uniformly. And we're in the very early stages of trying to figure out, you know, how little change there is on the bulk of the surface. Now, Stardust and Deep Impact were two very different spacecraft. And I think probably from your point of view, one of the biggest differences is that Stardust doesn't have a spectrometer, correct? Or color, for that matter. So really, the second flyby was all about morphology, all about the shape of the comet and what you'd seen change from the first encounter to the second one. That's correct. We had no compositional information. So, for example, we can't look for ice as we can with the spectrometer and the color instrument.

Of course, on the other way, there is a dust instrument on Stardust that is not on deep impact. However, we've now seen the dust environment at two different comets with that instrument, VIL-2 originally and Tempel 1 now, and we saw in both cases that the dust behavior is very similar. I was going to ask about that. You know, you've now seen three comets with two spacecraft, and so now can you translate what you've seen at Hartley 2 and compare to VILT 2 based on the kind of comparison to the deep impact data from Tempel 1? Can you go through all three of the comets and make those comparisons now? We should mention that VILT 2, of course,

was the first stop for the Stardust spacecraft, its primary and initial target comparisons now. We should mention that VIL-2, of course, was the first stop for the Stardust spacecraft, its primary and initial target out there. That's definitely the goal. I certainly won't claim that we can do it this instant, but we're starting to make those comparisons. And so, for example, there doesn't appear to be any VIL-2-like large, circular, sort of shallow depressions that you see on VIL-2 anywhere on Hartley. And we hadn't really seen them on

Temple 1 from the first flyby, but with this new flyby, there are regions that look more similar to VIL-2 than we had ever seen before. Perhaps the most enigmatic features on Temple 1 layering that we had seen on the front side the first time, and now see even more on the back side of Tempo 1, if you will, we don't see any real evidence of that on the other two comets yet. And of course, you have to account for the differences in scale and their histories. But yeah, you hit the big nail on the head, which is we do need to put all these things together into some common understanding of what's going on. And we're at the very initial stages of trying to figure that out. That's Stardust next, co-investigator Jessica Sunshine. She and Emily Lakdawalla will be right back with more about the spacecraft's flyby of Comet Tempel 1. This is Planetary Radio.

I'm Robert Picardo. I traveled across the galaxy as the doctor in Star Trek Voyager. Then I joined the Planetary Society to become part of the real adventure of space exploration. The Society fights for missions that unveil the secrets of the solar system. It searches for other intelligences in the universe, and it built the first solar sail. It also shares the wonder through this radio show, its website, and other exciting projects

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. Two great guests this week. University of Maryland Senior Research Scientist Jessica Sunshine is telling us about the February 14 Stardust Next encounter with Comet Tempel 1. Also joining the conversation is my Planetary Society colleague, Emily Lakdawalla. And since you're wondering, NEXT stands for New Exploration of Tempel 1.

Jessica, are we even anywhere near being able to say whether comets are more similar to each other or dissimilar? I mean, is there a lot of diversity among these bodies? Well, if we go back a few years, people had this impression that comets were, you know, snowballs, right? Dirty snowballs, we were always told. Dirty snowballs, sometimes we used to joke, were snowy dirt balls, which is probably more accurate. And that they were gently

put together when the solar system was formed, you know, small particles coming together and gently aggregating. And that basically they were all the same. Well, I think we know

that that's just completely wrong. They're not all the same. They don't seem to have the same compositional makeup. And we can see that from surveys of comets with telescopes. We can also see that very dramatically in Hartley 2 where we have different kinds of gases coming out of different parts of the comet. There was evidence of that at Tempel 1 from Deep Impact that there was outgassing of different types of material. And we also see that they've evolved differently over time,

different parts, and maybe in different ways. What's difficult to sort out, but certainly what we're all trying to do, is how much of what we're seeing in the diversity represents diversity that's primary, in that it formed that way originally when the comets were forming, and how much of it represents evolution. And undoubtedly, we have both going on. That's what makes this exciting. I always love it when a scientist says, we now know we were completely wrong.

I think that's one of the humbling things about space exploration, is that most of the time you're wrong, and every time you send a new spacecraft to a new place, you find out that everything you thought you knew was wrong, and you have to make up new hypotheses. And it's humbling. And the great thing about Stardust is we sent, you know, okay, a new spacecraft, but it was a place we've been. And I don't think any of us in our wildest dreams would have predicted what the backside looked like. Can you describe a little bit about what you saw at the backside that so surprised you? Well, first of all, we started to see, as you first came around, and I call it the backside just to distinguish it from the previous

one. It's probably not the best term. But as we came around to the new side that we hadn't seen before, we started seeing many, many more circular features than we'd seen before. And it remains to be determined whether those have to do with impact cratering or more likely have to do with outgassing. And it's always a bit surprising when you're used to something and you see a little bit more and it's not, doesn't really look like anything you'd seen previously. And there was, when we first came around a fairly large depression, which which again we hadn't seen before and i actually was in charge of trying to help put some of that particular figure together for

the press conference and i had one at that point then someone called out and said jess you need to see this and it was the next image or probably two images later so about a half hour later and that's when we really came around and we suddenly could see those layers that cut through over a kilometer of this new side sitting in a depression that, frankly, looks like it's something out of the desert southwest, not something you would see on a comet. And when we saw layers in the front,

it was sort of in a cliff face, about a 100-meter cliff face, and it almost was easy to suggest, well, maybe we're looking at two different pieces of comets that came together, and this is somehow some seam between the two. But this one is clearly not just that the layers are there, but they've also eroded in a very large scale. And I can tell you for sure that as several of my colleagues came over to look at this, we literally had jaws dropping. Cool. Yeah. Jessica, we're just about out of time.

To coin a phrase, what's next from Stardust Next? More science, more conclusions to come? Well, unfortunately, the spacecraft itself, as I think people know, is out of fuel. So it's being decommissioned. We've taken our last image. There is a lot of assimilation to do. I mean, you've seen all the images we have.

It's not like there's new data coming out. But it is really the hard work now, which is to sit back and try to figure out what it all means. And I think in the next three or so months, you know, we're working towards the science paper that will come out of this. And that's where we're really focused on both these new terrains as well as showing and interpreting what it was the actual deep impact crater site looks like. Emily, I'm sure you'll continue to follow all of this in the Planetary Society blog. I'll be paying close attention. I just got one other question, Jessica. You are part of the first generation of scientists with data gathered from comets

up close and personal. You got to feel pretty lucky. I feel amazingly lucky to be part of this. Hartley, too, was spectacular in so many ways. And, you know, we really weren't sure if the spacecraft and the camera and the comet were going to cooperate with Stardust Next, and it did in every way possible, and so you just have to pinch yourself at the end of the day. Congratulations on this, yet another very successful comet flyby, and thank you for joining us, as you have several times in the past here on Planetary Radio. No, my pleasure. It was great fun. Jessica Sunshine is Stardust

Next co-investigator, and of course she was the deputy principal investigator, or still is, I suppose, for Deep Impact Epoxy. She's a senior research scientist at the University of Maryland. And Emily, thank you for joining us. Always a pleasure, Matt.

And of course we'll hear from Emily again next week with her regular report on the best of the Planetary Society blog that you can always find at planetary.org. She is the science and technology coordinator for the Planetary Society and a contributing editor to Sky and Telescope magazine. You know who's up next. It's Bruce Betts with this week's edition of What's Up. That's just a few seconds away. It's time for What's Up with Dr. Bruce Betts, the director of projects for the Planetary Society, who's at the other end of the Skype line. And you're not going to rub it in, right, that I talked to Bill about going to the launch that I should have been able to see last November?

Maybe a little, but later. A little bit later. Yeah, no, we're glad Bill got to see it and, of course, glad that you didn't. What I really don't understand is why you're going to Florida a few days later. I know. It doesn't make much sense, does it? But it's unrelated. You should really drive over to the Cape and just look longingly.

Maybe I can smell the liquid hydrogen wafting through the breeze still. There's so many technical issues with that, but we won't go into it right now. Well, go into what's up in the night sky. All right. Evening, Jupiter, super bright over in the west. Beautiful little juxtaposition happening. March 6th, check out the crescent moon right near super bright Jupiter, low in the west, shortly after sunset. Saturn rising between 8 and nine saturn up high by middle of the night and looking kind of yellowish and it is above spica the brightest star in virgo and here's my my how to find spica find the big dipper you know that ursa major thing and take that curve that arc

and if you follow that arc in a curving motion of the handle of the dipper. You'll get to arc Taurus. Oh, clever. Very bright star. But wait, don't stop. Keep arcing along the same approximate curve, and you'll come to a bright star. About, again, across the skyways, and that will be Spica. And if you look above Spica, you'll see Saturn looking kind of yellowish. Spica looking basically bright, similar in brightnesses right now. Tricky, huh?

Tricky, yes. Yeah. Pre-dawn, Venus, super bright over in the east before dawn. We move on to this week in space history. It was this week in 1966, 45 years ago, that Venera 3, a Soviet mission to Venus that they were trying to make a lander on Venus, became the first impactor on Venus. But we do love it in Trivialand because it is the first human-made object to impact or touch the surface of another planet. Excellent. Thank you. And, by the way, you are on your own. You know, once again, there was kind of a science fiction element to that, which I can't explain, but I'm glad you pulled it off. I got to get out the theremin next time.

which I can't explain, but I'm glad you pulled it off. I've got to get out the theremin next time. Forbidden planet. So Discovery that we were just talking about launched this last week, STS-133. Don't rub it in. Sorry. Strangely, even though they never really tied these numbers carefully, somehow STS-133 has actually ended up to be the 133rd shuttle flight. It is the 39th flight for Discovery. This is tops among all the orbiters. Atlantis in second, currently with 32. And this is the 35th shuttle mission dedicated to station assembly and

maintenance. Discovery, the current grand old orbiter on its last voyage. Did you see that launch, Matt? Oh, wait. Sorry. Forgot. It was quite beautiful on YouTube. I can at least get it in high def. We move on to the trivia contest. Please. We asked you, not counting Apophis in 2029, what asteroid gets the brightest in the night sky? How'd we do, Matt? A variety of answers, but by far, those of you who entered seemed to believe that it was Isvesta. It is indeed.

Excellent. Well, Caroline Fletcher had it the most right, apparently, because Random.org decided that she would be this week's winner. Caroline Fletcher of Marion, Illinois, we are going to send you Solar System for iPad, or actually TouchPress. The publisher of Solar System for iPad is going to send that out to Caroline, so enjoy that on your iPad or your friend's iPad. Enjoy that on your iPad or your friend's iPad. This is that really cool interactive book specifically designed for the iPad, the author of which is Marcus Chown, a listener to the show. And congratulations, Caroline.

Congratulations. Throw in a little extra random space factage for you. Vesta reaches not quite magnitude 5, which means it actually does get naked eye visible during its oppositions, although they do vary considerably. But you'd have to be in a much darker sky than we are to see it. And you also may ask yourself, I'm sure you did, Matt, you've probably fretted about why. Why is it brighter in the sky than Ceres, even though Ceres is bigger? And it has something to do with that guy.

What's his name? Albedo. Gosh, you're right. First of all, it's a little closer. But a lot of the answer is due to that guy, Albedo. It has a much higher albedo, which is basically its brightness. So it's a much brighter object reflecting more light. There you go.

Thank you for that. We move on to our next trivia contest. Coming back to our friend Discovery, including the current flight, SDS-133, how many times did Discovery visit the International Space Station? Go to planetary.org

slash radio, find out how to enter. I know it was the champion, but we'll leave it at that. I'm not going to give any other hints. No, please don't. I certainly won't. You have until the 7th of March, March 7, that's Monday, at 2 p.m. Pacific time,

to get us that answer. Hey, and we've got a very cool prize. I will now tell you about it. Oh, yay. Livio Radio, which you can find at livioradio.com. They make these very, very cool internet radios that you can put around the house, and some of them have all the NPR stations pre-programmed, some have Pandora.

They have a new device called the Carmen, which makes it very easy to use, basically use Internet radio in your car. It's sort of a player and an FM transmitter, and you just plug it right in, and it works great. Well, anyway, they've given us a few of these to give away, and what better way to listen to Planetary Radio if you're one of our podcast listeners? You can catch it this way if you're not near one of our radio stations or a SiriusXM listener. So that's what we will have for the winner next week, or actually in two weeks when we award

this. Cool. I was impressed. You're easily impressed. True enough. But in this case you have good reason for it. Alright, we done here? Yes, we are. Alright, everybody go out there, look up the night sky and think about mechanical pencils. Not those lame ones that poke you, but really

well-designed ones which are so hard to find. Thank you, and good night. I never use them because I break the leads. I have a heavy hand. What can I say? Matt the Destroyer. He's Bruce Betts, the Director of Projects for the Planetary Society. He'll join us next week, right here, for

What's Up. How did amino acids, the building blocks of life, get into a rock that recently fell to Earth. That's our topic next week on Planetary Radio, which is produced by the Planetary Society in Pasadena, California, and made possible in part by a grant from the Kenneth T. and Eileen L. Norris Foundation. Clear skies. Редактор субтитров А.Семкин Корректор А.Егорова