Planetary Radio: Space Exploration, Astronomy and Science - Deep Impact Special

Episode Date: July 4, 2005

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Starting the fourth with a bang, 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. Here is the sound of a thousand or so people celebrating what may be the strangest climax of a space mission in history. It crashed! All right! Did you hear Bill Nye the Science Guy yell with glee, It crashed?

By doing so, Deep Impact did exactly what it was supposed to do. But no one suspected the spacecraft's violent end would be so spectacular. It happened right on time at 10.52 p.m. Pacific Time, July 3, 2005. The huge crowd gathered at the Howe Performing Arts Center in Southern California can perhaps be forgiven if they celebrated American Independence Day an hour early. They gathered that evening to hear a series of speakers and to follow the live action a few miles away at the Jet Propulsion Lab. That's where an anxious group of engineers and scientists were waiting for the big moment when the aptly named impactor portion of the two-part probe would hit the tip of Comet Temple 1 at nearly 23,000 miles per hour. The other part of the spacecraft, joined by

scores of telescopes back here on Earth and in Earth orbit, would watch for this minor big bang, revealing for the first time just what's inside these dirty snowballs that have fascinated humankind for our entire history. Bill Smythe is one of those Deep Impact Project scientists. He somehow tore himself away from JPL to join our comet-bashing party up the road. We started building this, I started building this thing about five years ago and before that a team of people, the science team, had proposed the mission once it got turned down. That took them a couple of years. They proposed again after making adjustments. It got approved

so they were already four years into the process and so this represents something like, tonight represents something like 10 years of their lives. It's about four years of mine, and frankly, I'm pretty nervous about what's going to happen in the next little while. We sort of know how to build spacecraft pretty well. Sometimes they fail, but not very often. The problem is, we don't know what the comet looks like. We don't know how it's going to behave, and a comet's a dangerous place to be. Basically, those jets that you see coming out of the comet are shooting things at about 100 meters a second, which is about 180 miles an hour. They're little fluffy things, we think. You know, a few micrograms or something like that. The problem is all we can see are the little fluffy things. It might be shooting big boulders, and we don't know that.

We also don't know how strong the comet is, which is why there's this big mystery about how big a hole it's going to make. You saw from the videos that up at Ames we can simulate what an impact's going to look like if you know what it's going to hit. But we don't know what's going to be there. We don't know how dense it is. We don't know how strong it is. But we do have a lot of clues. And we spent the first time part of the mission, almost a year, debating about what the comet's really going to look like. You have to worry about, is it bumpy? Is it shaped like a dish? And some of these things seem to be shaped like a dish. How about if it's shaped like a cigar? And this one sort of is shaped like a cigar. And you're trying to hit it, and you're trying to hit it right on the end. That's a pretty hard thing to do.

And once you've launched from Earth, you're stuck with the orientation of the comet. There's really not much you can do about it. We spent a lot of our time just worrying about those little pieces. We've got lots more details regarding Deep Impact, including the latest news, at planetary.org. No one was more excited about those details than Bill Nye the Science Guy, who serves as vice president of the Planetary Society when he's not on television making science understandable and fun.

But Bill seemed just as interested in the deep meaning of deep impact, which for him began with the bottle of water in his hand. Where did we get this water all over the earth? Well, not all over California, but all over the earth. It came apparently as near as anybody can tell. It came from outer space. That's weird. No? Yes? It's crazy. You know, now that I've tried it, I don't think I can live without it. I think it's fabulous.

But meanwhile, our society is launching this thing to try to whack an icy rock in deep space. Now, if you take a drink of water, you will know you just take it for granted. You take a drink of water every day. It's no big deal. You just take a drink of water. Take a drink of water.

Fine, fine, fine. But don't you wonder where that water came from? And the only reason you would wonder where you came from is if you wonder where everything came from. And I hope you go through a phase in life where you do wonder where everything came from. Now, tonight, you could say, this is a horrible waste of our tax dollars, this is silly, but you could also say for a few million bucks, we're going to find out what's inside this comet. And then we can find out where water came from. And if we can find out where water came from, maybe we can learn something more about ourselves and our planet and our future. And so this, I very, very much appreciate

you guys coming. I know it's a holiday weekend and you have big barbecues tomorrow. And I very much appreciate everybody coming out to sort of share this experience because I think you'll find that when we're all in the room together, we're all here together watching this thing, it means more. You guys are going to have to make decisions about how to spend tax dollars in the future. And I hope you continue to fund these exploratory missions. This is probably not going to enhance our national defense,

probably will not change our energy policy. I don't think it's going to change our foreign policy much. But we may discover something that's never occurred to anyone about our origins and our place in the universe. And so, thank you. Thank you. Thank you. You know, I tell this story often.

My third grade teacher, Mrs. Cochran, told us that we are grains. There are more stars in the sky than there are grains of sand on the beach. And it doesn't take much to convert that in your head to, I am just a grain of sand. I'm really hardly any different from a grain of sand. But yet you have this brain that allows you to understand all this. Now, in the case of my old boss, maybe not. But for most of us, we can understand our place in the universe. And tonight, we are going to get one more little piece of information, or

another few pieces of information. And it will be like the guy picking up the rock and inferring that this layer of clay, or these cooked bacteria indicate something

astonishing about the history of the Earth. So thank you all very much for coming. If you're not Planetary Society members, please join and let us go forward and, dare I say it, change a comet. I mean, the world. Thank you. We'll have more from Bill Smythe, excerpts of the first post-impact press conference, and an up-to-the-minute report from Emily Laktawalla

when Planetary Radio's special coverage of Deep Impact continues. This is Buzz Aldrin. When I walked on the moon, I knew it was just the beginning of humankind's great adventure in the solar system. That's why I'm a member of the Planetary Society, the world's largest space interest group. The Planetary Society is helping to explore Mars. We're tracking near-Earth asteroids and comets.

We sponsor the search for life on other worlds, and we're building the first-ever solar sail. You can learn about these adventures and exciting new discoveries from space exploration in The Planetary Report. The Planetary Report is the Society's full-color magazine. It's just one of many member benefits. You can learn more by calling 1-877-PLANETS. That's toll-free, 1-877-752-6387.

And you can catch up on space exploration news and developments at our exciting and informative website, planetarysociety.org. The Planetary Society, exploring new worlds. Welcome back to Planetary Radio, where we are devoting this week's show to the explosively successful Deep Impact mission. show to the explosively successful Deep Impact mission. It was almost time for that 370-kilogram or 800-pound copper projectile to smash into Comet Tempel 1. As the tension rose, project scientist Bill Smythe shared a few more of his thoughts with the hundreds who had gathered at the Howell Performing Arts Center to share the climactic moment.

Why do we want to go to the comet at all? Well, maybe in this environment it's a preemptive strike. We're going to hit the comet before it hits us. And there's some truth in that. We don't know how strong comets are. And if we wanted to get rid of a comet, we've really got to make a test sometime to find out what it would take to disperse it enough

so it wouldn't hurt the earth. But that's not really the most important part. Really the most important part about comets is we don't know how they work at all. Comets tell us how the solar system formed. They have some chemical composition of which we mostly just see the ions. We don't see the neutral chemicals because it's too far away. We don't know what the shape of the nucleus is really. We've got a few pictures now. Some of them look like smooth little potatoes and some of them look like little craggy things.

But the most remarkable part is how do we get enough energy in there to get all that stuff coming off? And how does it keep coming off again and again and again? We think it's frozen material. In fact, the model of a comet is you've got this hard rind on the outside covered with a nice layer of dust. Both of those are about two feet thick. And then all in the inside are just little fluffy pieces of snow stuck together.

That model seems to hold up with everything that we know so far. What drives the jets, it looks like it's something that melts at a temperature much lower than water. And right now we think, in fact, it's carbon monoxide. Except for commentary from Comet Bash moderator Bruce Betts, the big auditorium fell silent as we crept closer to the time of impact, a time adjusted for the minutes it would take pictures and data to reach us from 83 million miles away. The already amazing unprocessed images had been arriving for hours. Then came the moment you heard at the beginning of our show

when the signal from the impactor abruptly stopped. It meant that part of Deep Impact had been vaporized. Five anxious minutes later, the first image of that blast appeared on the big screen. That's it. How about that, you guys? Wow. Bang. I'd say it made a hole. Wow! Bang! I'd say it made a hole.

Even these raw, unprocessed images picked up by the Deep Space Network were awe-inspiring. Huge, straight-as-a-narrow plumes spread from the bottom tip of the comet's misshapen core. The energy released was obviously fantastic, and the images just kept on coming. Two hours would pass before a panel gathered in front of the TV cameras at JPL for the first post-impact press conference. One of the first to speak was Andrew Dantzler,

acting director of NASA's Solar System Division. Well, what a smashing success, huh? I can't resist. Just in case you missed it, we have a picture of the impact. There it is. That is phenomenal. I was trying to think of how to describe this, and I'm just plain speechless. I know Rick is going to go more into just how close this is to how it was modeled,

but I have to say I don't think anyone expected it to go this beautifully well. We soon learned just how well Deep Impact had performed. Both the impactor and the flyby portions of the spacecraft had found their targets with an error of no more than 50 meters. And they did this on their own. The great distance to Temple 1 meant that commands from Earth would arrive far too late to respond to the rapidly changing situation. So the probe itself had to figure out what to do.

Principal investigator Micah Hearn was nearly overcome with emotion as he summarized the very early results. We've got by far the highest resolution images of cometary nucleus ever from the impactor, and we're not even counting what we'll get from the flyby. So the impactor was perfect. The flyby instruments also worked beautifully. We got tremendous spectra, new spectral features, really strong spectral features, great thermal spectra. Ahern also talked about what comes next.

So the flight team has completed most of its work. We're just basically starting our work now, trying to make sense of what we've learned. Obviously, it was a very big impact. Presumably, we have a large crater in some one of those images that hasn't played back yet. The interpreting the ejecta cone, we obviously have lots of images of the ejecta cone. Interpreting that's going to take a little bit of time. There are lots of structure in it that's of interest to understanding the nature of the comet. We'll be working that out over the next half day and weeks and months and years. And I just look forward to a wealth of data that will take me to retirement.

Project Manager Rick Gramier was asked about the meaning of this mission, climaxing as it did for most of the United States on the 4th of July, Independence Day. I don't think we started out to send any message at all, actually. We're actually performing a science mission, and as you can see from listening to Dr. Hearn, we have a lot of science to be had here. That being said, I obviously hope that it's made America proud to see that we overcame a lot of challenges. A lot of people said we couldn't do this or wouldn't be able to pull it off. And the team stuck together through a lot of adversity and problems to work out and made it happen. And it happened like clockwork.

And I think that's something to be proud of on America's birthday. Our Emily Lakdawalla was at JPL both for the Impact and a second press conference held in the late morning of July 4th here in Southern California. You can read her Deep Impact blog at planetary.org. But we've also got her on the line for an update. Emily, thanks very much for joining us. It's been a long 24 hours for you. Thanks for having me.

It has been very long, but it was very exciting. Yeah, you were right in the middle of the action. That must have been exciting. It was pretty thrilling. We were watching what was going on in mission operations, and everybody was really waiting with bated breath to find out if the impactor was going to travel on target. And everybody was waiting to see those first images. And when they came down and we saw that smash, it was just unbelievable.

Yeah, of course, we had the same experience, 800 or so of us at the Howe Performing Arts Center, as people have heard during the program. Now, what we have not heard is what happened at the second press conference, which I guess you attended? Yes, I did. And I think the most exciting thing from the second press conference was seeing the first of the look-back images that the spacecraft is still capturing right now. You see the back of the comet. It's silhouetted against the sunlight, and the cone of ejecta is still spreading out from the comet. It is still expanding. Now, when you say the look back, this is the flyby portion of Deep Impact,

which actually sort of shut itself up, shielded itself as it went through the coma of the comet and then reopened and started grabbing these shots? That's right. Actually, it didn't have to turn itself off in any way. It just turned into a direction where it put some heavy copper shielding between it and all of the dangerous dust particles that are right in close to the comet. But yes, then it turned back. It's doing this look-back imaging for 60 hours after the impact. And then they'll pretty much mothball the spacecraft.

What conclusions, if any, have Mike Ahern and his science team been able to make from these images and other data? Well, I think there's a couple of conclusions. First of all, the comet that they saw, the nucleus of the comet in their high-resolution images, did not look at all like either Borelli or Vilt 2, which are the other two comets that we've seen very close up before. There were some spots in these comets that looked a lot like impact craters, which really surprised them. Its shape was very different, and it had a lot of topographic features

that were simply not like ones that have been seen on those other comets. I guess, of course, it's still rather early to be expecting them to draw any conclusions from what they're seeing. It is pretty early, and they were very careful to say that everything that they were saying was the merest speculation based on absolutely no sleep and days running on adrenaline. But what they did say was that it looked like the behavior of the impact meant that the impactor passed through a relatively thin layer of very loose, dusty material and then may have hit some harder, icy material that caused a different kind of explosion after the first flare.

Did they, having just heard, of course, that they are not prepared to talk about this, have they now, do they have any speculations about the spectral information they're picking up from the light of this explosion, which, of course, will tell us about the chemical makeup of this comet. It will tell us about the chemical makeup of this comet. Another thing that they're hoping that the spectral information will tell us is how big the crater was. The problem with figuring out how big the crater was is that the crater is hidden behind all of the dust that the impact threw out, and they think that the best way to figure out how big the crater was is to look at the temperature information that they get from their spectral data.

They figure that the crater is going to show up as a cold spot on the surface of the comet. Now, of course, this is a very important question to the thousands of people who are waiting to hear who's going to come closest to guessing the size of that crater so they can win that nice prize. That's right. And Mike Ahern said it may be a week before they're able to figure out how big they thought the crater was. However, they could say one thing, and that's that the crater is definitely big. It's not on the house-sized end of the scale. It's more on the stadium-sized end of the scale.

So they say they know who they're going to be taking money from. They're just not sure who they're going to be giving it to yet. Emily, where does this mission go from here, and where does your involvement go? Is your blog now complete, or will you be continuing it? Well, the web blog on the Deep Impact mission itself is pretty much complete because there's probably no more live events to be following. But we'll actually be maintaining this weblog online, both with me and with occasional guest bloggers giving their commentary on whatever's going on in space

exploration right now. As for the mission, like I said, they'll be doing this look-back imaging for a total of 60 hours after the impact. And then it sounds like they may just sort of mothball the spacecraft. They'll put it in a position where its solar panels are pointed toward the sun, so it maintains in a nice positive energy state. They'll maintain the ability to communicate with it, but it won't have any science commands for now. However, the opportunity is still out there that if there is a favorable geometry set up, they could possibly use this to look at another comet if they pass by one really closely. Wouldn't that be amazing if this incredibly successful spacecraft gets a new life someday?

Emily, we're just about out of time. Thanks very much for joining us on this Independence Day and giving us an update on the Deep Impact mission. Thanks for having me. Emily will be back next week with her regular Q&A segment, and I'll be back in a moment with a special Deep Impact edition of What's Up. Time for What's Up with Dr. Bruce Betts, the Director of Projects for the Planetary Society, as we speak quietly because we are... We are backstage at the Howe Performing Arts Center at Comet Bash 2005,

the Planetary Society's celebration of the Deep Impact event. Now, you just came offstage because you're the moderator tonight, and we had, what, 800, 900 people out there cheering because something incredible happened, an impact. We did indeed. There definitely was an impact and it spewed lots of stuff out and by the time people hear this, they'll know a lot more than we do now, but we know there was an impact and it was really pretty.

Well, tell us what we do know. What's up? Well, what's up in the night sky is you can still see some nice planets in the evening sky and low in the west. We've got Venus looking like the brightest object in the night sky, a star-like object. Mercury still very close to it, a dimmer object, but setting in the next week or two. Saturn already pretty tough to see, much lower than they are. And we've got Jupiter higher up in the west to southwest. Now Jupiter is also near bright star Spica. Jupiter is the second brightest star-like object up there. Jupiter and

Spica I mentioned because they are near Comet Tempel 1, what Deep Impact just slammed its impactor into. So if there is brightening, which you probably have heard about by now if you're listening out there, and we don't know yet, then go out out there and look you need a dark site if it doesn't brighten much you'd need a very dark site of a nice telescope if it brightens up as they expected and they seem to have gotten a lot of you know initial indications are that they get a lot of material off there it might get up to naked eye brightness from a really dark site or binoculars at least so you might be able to use binoculars to see this thing. Find a sky chart out there on the web.

They'll be popular now that the mission worked, and find out where to look. Moving right along, let's go on to, oh, I'm going to have to be quiet with this. Random space fact! Interesting approach. Oh, thank you very much. Thank you. Yeah, it's my advanced radio skills. I love that interpretation. Oh, thank you very much. Thank you. Yeah, it's my advanced radio skills. Love that interpretation.

Oh, thank you. Now, I just thought it might be appropriate to cover the Deep Impact mission. And some of these things may have been covered. So here are two or three quick random space facts about the mission. Hit the comet at 10 kilometers per second. That would get you all the way across the United States in about six or seven minutes, that speed. Extremely fast. Lots of energy released.

Also, you've got the flyby spacecraft actually turns and puts shielding in front of it as it passes through the coma of the comet trying to get images of the post-impact site. And we'll talk about that a little bit more in the trivia contest. Speaking of the trivia contest, let's talk about the last one where we asked you what Volna, the Volna rocket that Cosmos 1, Solar Sail, launched on, the bane of our existence,

the Volna rocket, what does Volna mean in Russian? What does it mean? Tell us, Matt. How did we do? Lots of entries. We had some from people who obviously have good reason to know. For example, Irina Masunovsky wrote to us and said that Volna, she got it right, does mean wave. Now, Irina, I'm afraid you weren't our winner, but we do appreciate that you've pointed out that, she says anyway, that we've been pronouncing it incorrectly, along with Lou Friedman and everybody else in the world. It's Volna, second syllable stress, Volna.

So there you go. That's what Rina says. That's what we're all about is learning from our listeners and trying to teach them as well. So Vol-na to you as well. Thank you very much, and we're sorry you weren't randomly selected as the winner, but who was, Matt? Our actual winner this week, who may also have some idea of how to pronounce Vol-na, is Svetlana Abdush.

Svetlana Abdush of Omaha, Nebraska, who also correctly said Volna means wave, as in radio wave or a wave of water. So congratulations, Svetlana. You get... We're still giving away posters, I think. Yes,

indeed. That's what she's going to receive. But for our next trivia contest, shall we give them a Planetary Radio t-shirt, Matt? Why don't we? Let's go back to that. All right. So for this contest, answer the following question to win a Planetary Radio t-shirt and be the envy of all of your friends, enemies, and acquaintances. When the Deep Impact Space flyby spacecraft heads through the coma of the comet. It is going to use what is called a Whipple shield to protect itself. Same thing Stardust spacecraft used when it flew through and collected samples from a comet that will return next year. Who is the Whipple shield named after?

And by the way, we need more than just a last name in this case. And go to planetary.org slash radio to find out how to email us your answer. It was not the Mr. Whipple who sold toilet paper, right? Oh, God, now I need a new question. I'm tired, Matt. Don't do this to me. Because a lot of toilet paper would probably make a pretty good shield. Hey, don't squeeze the comet.

You have until July 11, July 11, 2005 at 2 p.m. Pacific time to get your entry into us, and you might win that Planetary Radio t-shirt. That's it, folks. No more sale posters for a while, anyway. Bruce, I think we're done. All right, everybody, go out there, look up at the night sky, and think about explosions. And you're going to be going out back on stage in a minute, right? You and Bill Nye and Bill Smythe.

I am indeed. All right, Bruce, thanks very much. Go out there, do your job. He's Bruce Betts, the director of projects for the Planetary Society, and we are standing backstage at the Haw Performing Arts Center at Citrus College where we've just had a comet bash. Thank you, and good night. That's it for this special edition of Planetary Radio.

We hope you've enjoyed it. Our show is produced by the Planetary Society in Pasadena, California. Write to us at planetaryradio at planetary.org. Have an impactful week, everyone.