Planetary Radio: Space Exploration, Astronomy and Science - Astounding Comet Hartley 2

Episode Date: November 22, 2010

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Hi there, podcast listeners. Been a long time since I've sent you a special secret coded message like this. Bear with us. I've got a favor to ask. And that favor is, since you likely get us from some podcast aggregator, and very likely that aggregator is the iTunes store, we've noticed that there is a bit of a review gap between us and some of the competition out there. Now, there are all kinds of great space exploration shows out there, and we hope that you count us as one of those, and that maybe you'd be able to or be willing to share that opinion with others. It's real simple to do. Just about every aggregator allows you to rate us one to five stars and maybe even add a few comments if you like. This seems to mean a lot to Apple and others, and it would mean a lot to us if you could help out a little bit. Thanks so much for considering taking a few seconds to do this.

We really appreciate it, and we hope you'll stay tuned. I think we've got a really great show for you today, Conversation with Jessica Sunshine. Thanks for listening. Deep Impact does it again 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. Deputy Principal Investigator Jessica Sunshine returns to tell us about her spacecraft's second astounding encounter with a comet. These are pictures you really have to see.

Emily Lackawalla shares news of another big accomplishment in the exploration of our planetary backyard. She's also got a stack of children's books about space. Bill Nye, the science and planetary guy, salutes a second solar sail. This one launched into the black just a few days ago. Bruce Betts and I will wrap it up with What's Up, this time featuring a little ditty composed by one of your fellow listeners. I think you'll enjoy it, but probably not as much as Bruce and I do. So, Emily, I think I'm going to start by calling you a cub investigative reporter, Emily Lakdawalla, this week. Well, I wish I could take credit for digging up the story myself,

but it was based on a tip. I figured out that the highest resolution images from Deep Impact don't actually show all of Hartley 2's nucleus at closest approach. They're kind of off center. And that was a little bit of a piece of sad news to me. But I guess they made lemonade from lemons when they found these snowballs in the images coming off the nucleus. Yeah, those certainly are incredible. And we're just about to talk with Jessica Sunshine about those. So good work, Emily, and great coverage on the blog. Let's go to a different spacecraft, Hayabusa. That's right. This is such an exciting story. You know, Hayabusa was the spacecraft from Japan that went out to an asteroid and back. It came back in June with a sample return capsule that nobody knew if it contained any samples

from Itokawa or not. And they've cracked open one of the two sample chambers, and it looks about as clean inside as it did on the day it was launched. So they devised a special Teflon spatula that they used to scrape out the inside, and they came up with some dust particles, but then they had to spend months trying to figure out whether those things actually had come from the asteroid or not. And this week they announced that they've got at least 1,500 particles that most likely came from an asteroid,

which would make it the first sample return from the surface of a place beyond the moon. It's actually the fourth sample return mission. Genesis and Stardust picked up stuff from space. But this is the first surface sample return mission from beyond the moon. So congratulations, Daxa. Just a little bit of time left, and you reviewed some great books for young people on the moon. So congratulations, Daxa. Just a little bit of time left, and you reviewed some great books for young people on the blog. Yeah, I've been trying to be good about requesting books for review, and I got some great ones this year. There's a couple that I can

recommend that would be great for both kids and adults. The first one is called Almost Astronauts, 13 Women Who Dared to Dream by Tanya Lee Stone. And it's about a group of women who I have actually never heard of, the Mercury 13, a bunch of women who were put through the same stridium selection testing that the Mercury astronauts went through. And of course, they never got a chance to flew, but they were the pioneers who eventually enabled women mission specialists and finally pilots to fly aboard the shuttle. It's a frustrating story sometimes, but these women's stories are absolutely incredible, considering what they did in the age in which they did it. The other one I recommend is Team Moon, How 400,000 People Landed Apollo 11 on the Moon.

And this one's the story about everybody but Neil Armstrong and Buzz Aldrin and how many people were involved in making that mission a success. So those are two great reads for both middle elementary kids and adults. And I wish I had time to ask you about First Kid on Mars just because the cover looks so great. But, folks, you're going to have to go to the blog to check that out. Emily, thanks as always. Thank you, Matt. Emily Lakdawalla is the Science and Technology Coordinator for the Planetary Society

and a contributing editor to Sky and Telescope magazine. and a contributing editor to Sky and Telescope magazine. Back in a moment with Jessica Sunshine of Deep Impact Epoxy, right after we hear from Bill. Hey, hey, Bill Nye, the planetary guy here, executive director of the Planetary Society. And last week, last Friday, NASA, the National Aeronautics and Space Administration, launched NanoSail-D. Now, NanoSail-D is a very small sail. Now, the word sail on a ship refers to big pieces of canvas, nowadays perhaps big pieces of Dacron or Kapton, a polyimide material. Okay, fine. Well, this sail is made of mylar, which is another polyimide, fantastically thin, and even at 400 kilometers

above the Earth's surface, it will pick up enough aerodynamic drag to have its orbit decrease, decrease, decrease, and eventually burn up in the Earth's atmosphere. And you say, why heck, that's a waste of somebody's time. No, it's the coolest thing. If this works, of somebody's time. No, it's the coolest thing. If this works, these things will be attached to spacecraft so that they can be deorbited, taken out of orbit, without the need for extra fuel and extra kind of telemetry and all sorts of complicated stuff. This could be a new, easy way to clean up space debris. But wait, wait, there's more. NanoSail-D was the original idea that our own Planetary Society's LightSail-1 is derived from. We got the idea to use this deployment scheme, this spread-the-sails-out scheme with these cool stainless steel booms out in deep space.

We're doing all this based on the technology that NASA started and then abandoned several years ago. So we will learn from this. We will see how NanoSail-D deploys. Oh, D stands for drag, by the way. We'll see how it drags. We'll see how it tumbles. We'll see how it flies. And we will learn from that to make LightSail-1 work that much better. Oh, my friends, it's a small little spacecraft, but it may help us, dare I say it, change the world. I got to fly Bill Nye the Planetary Guy. Maybe you were with us when Deep Impact lived up to its name on the 4th of July, 2005. That's when its copper projectile slammed into Comet Tempel 1. Exactly five years and four months later, Deep Impact had another encounter with a comet,

and this time the comet struck back. As the spacecraft flew past Hartley 2 on November 4th, it revealed the most active comet yet back. As the spacecraft flew past Hartley 2 on November 4, it revealed the most active comet yet visited. It's quite a sight, especially in the high-resolution image unveiled at a NASA press conference late last week. Deputy Principal Investigator Jessica Sunshine was there with Principal Investigator Micah Hearn and other leaders of the Epoxy mission. Epoxy is the somewhat strained acronym for Extrasolar Planet Observation and Characterization. It has been nothing less than a second life for Deep Impact. Jessica, welcome back to Planetary Radio. You know, I asked you right after the flyby on November 4th if you would come back on the show,

and you wisely said, Matt, why don't we wait a couple of weeks? There might be some additional news. And boy, was that good advice. Yeah, we had hints of it as literally as we were leaving for the original press conference, but not enough time to have assimilated it. But I knew it was coming. Well, now there are the most amazing images. These really are set apart from anything we have seen up close and personal at a comet before, right? But, you know, we looked long and hard for evidence of ice in the coma at Tempo 1 and saw nothing. So when you take the same camera to a different comet and you see a completely different answer, it's astounding. You didn't have to just look for it here.

You ran into it. We did, probably. Yep. And I guess it's a testament to the spacecraft or to the fluffiness of this stuff that apparently didn't do any damage. That's right. The spacecraft is 100% healthy. It's a combination of things. The spacecraft was pretty far away, you know, 700 kilometers, 435 miles away.

And these particles, while there seem to be clumps that we can see, really must be very fluffy aggregates. So I think if we did hit one, it would break up very quickly. And they seem to be moving under a meter a second or so. So pretty slowly. You compared them to dandelion puffs. Yeah, that's right. I mean, it's probably more empty space than it is got, you know, ice chunks in it. I think your first impression is hail or something, you know, an actual piece of an ice coming at you. But these things are apparently quite porous. Some of the images that I saw, and by the way, I got these out of my colleague,

Emily Laktawala's brilliant article written the day of the press conference. She is so grateful to you folks for posting not just the fixed up, the prettied up image from your high-res resolution imager, the before image as well. The contrast there is quite astounding. Yeah, first of all, Emily's blog is wonderful. She did a great job of reinterpreting what we said in a way that's very easy to understand. We've had a philosophy, particularly on this mission, of, you you know we want to tell the story as it actually happens and we have an out-of-focus camera and the only way to to unfocus it or

deconvolve the image back into something that's closer to focus is a lot of manual labor so we can't do it quickly and that's why we couldn't do it during that first press conference and it can't happen sort of in a pipeline it's kind of one at a time. And there are always artifacts even in the process, but there's still obviously fantastic information at the end of all that work. And I've never seen a more dramatic example of that. No, I couldn't agree more. It is absolutely beautiful. I'll tell you that now and then I give away that I'm a Trekkie.

I think it was the opening to the Star Trek Voyager series where the craft passed by the tail of a comet. Correct, absolutely. And you could make out individual particles. Well, nothing reminded me so much of that science fiction image as this picture that you guys returned

from the real thing. Yeah, I'd forgotten about that but you're absolutely right, yeah. I always was happy that they passed by a comet. Yeah, I bet. I am not surprised to hear that. And of course, we'll put up a link on the show page at planetary.org to Emily's great coverage as well. Describe that image to anybody who has not seen it yet. I mean, what really is so exciting and unique about this? The first image that Mike showed is just one of those heart-stopping moments. It's the end of the anti-sunward side of the nucleus, so the part that's not rotating into sunlight. And you can see the terminator, the line between daylight and darkness.

In the dark side, you can see, oh, I would say a dozen or so jets coming out of the dark side of the nucleus. And because they're putting out dust with them, you can actually see the entire silhouette of the nucleus, even the part that's in total darkness. And then as you sort of try to take that in, you realize there's particles everywhere and they're not stars. So that's actually just, you know, ice just coming right off the nucleus so there's stuff going every which way as i said it's one of the most dramatic pictures i've ever seen short of the impact experiment we did at temple one did you immediately start to try and track some of those particles because you actually can yeah i mean the first thing we did was the the flicker movie that i know emily has on her website too that p Pete Schultz showed of just, you know, two or three frames, one after the other, go back and forth.

And you can see the particles moving from frame to frame. Your colleague who you just mentioned, Pete Schultz, he's the one who compared this to looking into a snow globe that's just been shaken up. Right. That was a brilliant comparison. That's very good. I think it's a great analogy. There's so much more that has come out of this data, and I guess part of it has to do with this kind of split personality of this comet, where you've got different stuff

coming out of different pieces of it. Right. Well, the real power, and I'm a bit biased, but the real power of the set of instruments we have is in the IR spectrometer because it allows us to do composition. And what we've been able to do is measure, in particular, carbon dioxide or dry ice. First of all, it's something that you can't measure from the ground, so we don't know very much about it in terms of what comets do. We were able to see that the two ends of the comet, which are the kind of rough ends, are producing tremendous quantities of CO2 relative to at least Temple I,

which is the only comet we've seen like this. It's there that we found the ice crystals. we've seen like this, it's there that we found the ice crystals. So it's the CO2 that's dragging the ice with it as it sublimes out of the interior of the nucleus. And the waste, which is that middle part of the nucleus that's smooth and appears to be covered in dust, has essentially no CO2, in a relative sense anyway, and is devoid of ice crystals. But that, to our great surprise, when we went to look for it, is where we found a high concentration of water. We just assumed the water would follow the ice, and it certainly does.

There is ice, water around the ice as it sublimes in the coma. But this, in the middle, is actually ice that must be inside the nucleus that is reacting to being in sunlight, eventually making its way through the dust grains to heat up interior ice that then percolates out. And so we see water coming out of the comet in two very different forms at the same time. And that's a far more complex environment than anybody ever envisioned was going to happen in a comet. That's Jessica Sunshine. She'll be back with more about Deep Impact's flyby of Comet Hartley 2 when Planetary Radio continues. 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. The Deep Impact Probe is now on the epoxy mission

that just climaxed with the flyby of Comet Hartley 2. Deputy Principal Investigator Jessica Sunshine was just telling us about something that was entirely unexpected. This is a bit of an oversimplification, but the somewhat dog-biscuit-shaped Hartley 2 is spewing carbon dioxide from its two ends, while the so-called waste of the comet nucleus is jetting out water. Is this just a total head-scratcher, or are people starting to think, okay, maybe here's how to explain this?

Well, I think there are certainly big open questions about why the ends in the middle of the comet are different. One possibility is that they always were different, and that there isn't, for example, just never was as much CO2 in the middle as the pieces in the ends. And that would say that when the comets formed, there was a lot more diversity in the material in the outer solar system than many of us think was supposed to be the case anyway. It's also possible that it had the same amount of CO2.

It just ran out because for some reason it was in sunlight more of the time than the rest of the nucleus. out because for some reason it was in sunlight more of the time than the rest of the nucleus. And the third possible one, which I actually tend to favor at the moment, is that the dust on the top, which is sort of redistributed from the material coming out of the ends because it's a gravity low and it's collecting there, is actually affecting the insulation and maybe heat is just not getting to the CO2 that's in the center of the nucleus. Maybe heat is just not getting to the CO2 that's in the center of the nucleus. But it all comes back to comets not just being simple snowballs or dirty ice balls, if you will, that were put together and they're all the same.

And they all come from the outer solar system and the outer solar system was all the same. And we have evidence of that, for example, from the stardust samples that returned, where they found evidence of minerals that were formed at very high temperatures that evidently are part of a body that existed in the outer solar system. So there's a lot more mixing in that early solar system than perhaps we thought. This seems to fit a theme that we hear over and over and over on this show,

which is that the universe, as we learn more about it, and the solar system, are far more diverse than often theories have accounted for. Yeah, I think that that's clearly one of the results of exploration. You know, you have very simplistic models of how things are, and theory is always easier with simple models. And you go and check, and reality says, wow, it's a lot more complicated than that. And then we iterate with the theories on how it could possibly be that way. There were hints in what was said, and Emily picked up on this.

Perhaps there are more of these HRI high-resolution imager pictures still to come? Oh, I mean, we collected 120,000 images. Oh, yeah, I guess there are a few then. I can guarantee you that there are more. I think what she, what Emily was getting at is that there, you know, are there higher resolution ones? And the answer is there are. You know, we have had a single-minded focus on this coma and trying to understand and present the snowstorm story, if you will. And as I said, the processing is very manual. We really hadn't gotten very far into the nucleus issues yet.

And that's also, quite frankly, where the artifacts become much more difficult because you have real features on the nucleus. And so when you try to de-blur them, you can create bizarre ringing effects that even if it happens in the ice crystals, you sort of ignore them because there's nothing there but it's either a point of light or it's dark. This is a good deal more complex than pushing a button in Picasso or Photoshop light. Absolutely. a button in Picasso or Photoshop light. Absolutely.

Now, Emily did do an incredible detective job and recognized that there was a situation that we're certainly not trying to hide or anything, that at the absolute closest approach, the high-resolution telescope was not pointing at the nucleus. That's really, quite frankly, a matter of luck. And you can't be lucky 100% of the time. And as it turns out, because there were these ice crystals, there was very interesting science to do off the nucleus. Yeah. You know, it could have been, you know, that we were looking at dark sky and we're not.

You can see that if you just look at the original five images we brought down. The nucleus in the medium resolution imager kind of wanders to the corners. It's obvious that there's going to be much more science coming out of this flyby, and you're not even done observing this. That's right. We keep taking data of the comet until Thanksgiving Day. People are working Thanksgiving, unfortunately.

And then we have a couple of calibrations to do after that. This object, which is just spewing this stuff out, how is it that it's still able to do this? Why does it have any fuel left, if I can put it that way? Well, it hasn't been doing it for billions of years because it's mostly spent its life in the outer solar system. And at some point it was perturbed by Jupiter and brought into the inner solar system, or perturbed by something else probably, but eventually by Jupiter and brought into the inner solar system, or perturbed by something else probably, but eventually by Jupiter. And the other issue is it hasn't always had a perihelion, a closest approach to the sun, this close to the sun.

That's only been a matter of years, I think, maybe a hundred years. So it hasn't been in this high heat roasting it quite as much as it has lately. But if it stays there, you know, yeah, it certainly has a finite lifetime. Jessica, you must be very proud of both your spacecraft and your team. I just want to congratulate all of you on adding yet another set of absolutely incredible images that are telling us so much about our solar system and all the objects that live in it. I am very proud of both our spacecraft, and we have a fantastic team. So thank you very much.

I also want to thank you for taking a few minutes to talk to us on what is your first day off in quite a long time, you said. It is, and I'm happy to do it. We'll let you go back to looking around before you have to go back to deconvoluting or whatever. Right, Thank you. Jessica Sunshine is at the University of Maryland in the Department of Astronomy, not surprisingly. But for purposes of this conversation, it's more significant that she is the deputy principal investigator for the Epoxy mission. And it's the Deep Impact spacecraft, which, of course, we've been following for years, which just about two weeks ago

had this quite amazing flyby of Comet Hartley 2. We'll fly over and check out the solar system, other parts of the solar system, with Bruce Betts when we get to What's Up just a few moments away. Would you believe it? Bruce Betts is once again on the Skype Connection. Maybe next week I'll be able to catch you in person. It's getting kind of ridiculous, isn't it? I still haven't given you your gift from the Kennedy Space Center. Don't cry.

Don't cry. Don't cry. Really, it's not. You still have it, right? I do. It's here somewhere on my desk. Yeah, it's here. Here it is. What's up in the night sky?

Jupiter dominating the evening sky, really bright star-like object up in the southern part of the sky in the evening. And in the pre-dawn Venus, super bright Venus, low in the east, doing that morning star thing before dawn. And to its upper right is the star Spica, much fainter. And high above that is Saturn. On to this week in space history. Mariner 4 was launched this week. It would later become the first spacecraft to fly by and take data at Mars. And then also this week, a few years later,

Mariner 4 was 64 and 71. The Soviet Mars 2 probe becomes the first artificial object to slam into Mars. Yeah, and Mariner 4 was the one that disappointed everybody with Mars until we got out there again with an orbiter, right? Yeah. All three flybys happened to see the really cratered highlands in a fuzzy kind of way and looked like Mars was another lunar-type surface, kind of missing the canyons and giant volcanoes and other exotic stuff. Thank goodness that was taken care of.

We will go on to Random Space Fact. Now, in spite of the fact that Bruce just did that do-it-yourself Random Space Fact, we have something very special to play for people, and it comes to us from Brandon Cook of Indianapolis, Indiana. Here it is. I love what's up. So what's up? All right, everybody, go out there, look up the night sky and think about two moons of

Mars. Think about a thousand Earths inside Jupiter. Think about the date of closest approach. Think about Apollo 11. Random space fact! Random space fact. Planetary radio t-shirt. Think about new planet stuff.

Think about Amelie Lough-Dawalla. Think about return samples from the moon. Think about the densest moon in the solar system. Think about Amelie Lock the Wallah. Think about return samples from the moon. Think about the densest moon in the solar system. Think about an orange kiss. Think about a cookie. Think about Mercury. Neptune. Think about natural form of drier land.

Random Space Fact. Just saying the three words. Random Space Fact. Specifact Just saying the three words Random Space Fact Think about The largest telescope in operation Think about daytime and nighttime Think about what humans are able to accomplish

In space Think about the local fluff Particles coming out from the sun Protons Electrons Particles coming out from the sun. Protons. Electrons. Particles coming out from the sun. Planetary radio t-shirt. Protons.

The immediate galactic neighborhood of the solar system. Planet formally known as Pluto. You ready? This week in space. Io. Local bubble. I did not know that. Yeah.

Dawn of the space age. Well, I'm never going to find anything to rhyme with that. You will be able to find your way no matter where you go in the solar system. That's really cool. Bruce Fetz, the director of projects. That's it. We're done. Thank you.

Good night. Nice work, Brandon. Huh? Think about how cool that was. That really was. You do have a random space fact, so go ahead and give us that. That was really cool. Talk about your friend that you tried to watch launch, Space Shuttle Discovery, the Discovery orbiter of the shuttle orbiters.

It has the most flights. In fact, it has the most flights of any spacecraft. spacecraft. Also the longest orbital lifetime for orbiters, having its first flight in 84, and it's orbited the Earth 5,628 times, docked with International Space Station 11 times. Golly goshness. Very, very impressive. And they will get it off. And I think they've pushed it to early December now. So, you know, I'll say it again, Godspeed Discovery. You know, you keep saying that and they keep not being able to launch. Maybe I should stop. Coincidence? You be the judge. We asked you last time around, who was the first international space station crew, the three members of Expedition One? How did we do, Matt? We're running short of time, so I'm just going to jump right in and tell you that our winner was Kamil Stefaniak of Poland.

Might be Warsaw. I'm not sure if this is the Polish spelling of Warsaw or not, but what I am sure of is that he got it right. William M. Shepard, Yuri Pavlich-Gidzenko, and Sergei Krikalev were the members of the Expedition 1 crew. Kamil, we're going to send you a copy of Mary Roach's book, Packing for Mars. And congratulations.

Congratulations. And we'll go on to our next contest, Back to Discovery. As of now, in other words, prior to its last scheduled flight, how many flights did the Space Shuttle Orbiter Discovery have? Go to planetary.org slash radio, find out how to enter. And you have until the 29th of November, the 29th of November, Monday at 2 p.m. on that day to get us your answer. And since we're recording this before it happens, happy Thanksgiving, Bruce. Happy Thanksgiving.

Everybody go out there, look up at the night sky, and think about, think about, think about turkey. Thank you, and good night i sure will he's bruce betts he's no turkey he's uh the director of projects for the planetary society he joins us every week here for what's up planetary radio comes to you from the planetary society in pasadena california and is made possible in part by a grant from the kenneth t and eileen l. Norris Foundation. Clear skies.