Planetary Radio: Space Exploration, Astronomy and Science - Deflecting Asteroids Headed Our Way

Episode Date: December 13, 2004

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. that takes you to the final frontier. I'm Matt Kaplan. We know they're out there. We haven't found the one headed our way, but it's just a matter of time before we do. And then what? We'll hear from a group that is making plans right now that may one day save the planet. Later, Bruce Betts will tell us where to look for all five of the other planets you can see without a telescope

in this week's What's Up segment. Here are some space headlines to get us started. Out there well past the asteroid belt, Cassini-Huygens has once again made a run at Saturn's moon Titan, this time passing just 1,200 kilometers above the surface of the Hays Obscured Body. Observations of at least one other moon are also planned. NASA has decided that teamwork will further the search for extrasolar planets. The new partners are the venerable Hubble Space Telescope and the much newer infrared Spitzer telescope that has joined Hubble in Earth orbit.

The instruments are studying the belts of gas and dust surrounding young stars, from which planets are probably formed. You can check out the images at planetary.org. And space shuttle Discovery has reached a big milestone in its long trek back to space. The craft's main engines have been successfully installed, keeping it on track for a planned return-to-flight mission in May of 2005. I'll be back in a minute with Apollo astronaut Rusty Schweikert, chairman of the B612 Foundation. The what?

You'll find out right after Emily visits the asteroid belt. Hi, I'm Emily Lakdawalla with questions and answers. A listener asked, what is the density of the asteroid belt? Is it a great mass of colliding rocks or is it made up of random objects that never come close enough to touch? The density of the asteroid belt? Is it a great mass of colliding rocks, or is it made up of random objects that never come close enough to touch?

The density of the asteroid belt is very sparse. There are millions of asteroids, which makes it seem as though the asteroid belt must be jam-packed with rocks that collide with each other constantly. But as many asteroids as there are, the number of asteroids is nothing in comparison with the vast amount of space between Mars and Jupiter, in which most asteroids roam. Furthermore, asteroids are very small. If you managed to squeeze all the main belt asteroids together into one object, that one object would be much smaller than our moon, or about the size of Saturn's moon, Minus. Does that mean that collisions never happen in the asteroid belt? Stay tuned to Planetary Radio to find out.

Nobody likes getting hit by rocks. The dinosaurs never got over the one that hit them. We know that it's just a matter of time before another big asteroid finds the Earth. A 100-meter rock will feel more or less like a 100-megaton H-bomb. Not so bad if it lands in an ocean, but devastating if it smacks a city. And then there are the kilometer-wide ones. It's a good thing they're much rarer, because they could kill, well, a lot more than the residents of a single city. Asteroid strikes are alive and well in Hollywood, what with feature films and now even the West Wing on television taking up the subject, but you might be surprised to learn how little

is being done in the real world to prepare for the inevitable. Yes, there are searches underway and more ramping up, but who is getting ready to send Bruce Willis out there to save us all? Just over three years ago, a group of astronomers, astronauts, and engineers met to consider this question. The result was the B612 Foundation, a non-profit group dedicated to developing nothing less than the technology to save our home world. Earlier this month, the Planetary Society played host to some of the Foundation's leaders.

In the audience were many of the most distinguished space scientists in the nation. Recent Planetary Radio guest Rusty Schweikert was the lead presenter. Sound familiar? Rusty was part of the crew of Apollo 9 back in 1969. Now he serves as chairman of the B612 board, among other things. He began by laying out the foundation's ambitious goal. This is a Kennedy-esque goal that we determined in our very first meeting. We wanted to make it short and snappy, but very precise, to deflect an asteroid in a controlled manner by 2015. And we're not saying to write a paper about it, to think about it, to talk about it. We're saying deflect. Our goal is to deflect an

asteroid, that is to move an asteroid, to change its orbit by 2015 in a controlled manner, not just randomly. You're talking here about humans modifying the solar system. I mean, you know, we haven't done that before. We visited it, we mucked around on the surface of things, but we haven't exactly changed the configuration. And that's really what we're talking about here. Have you figured out why they call themselves B612? Someone in the audience said it sounded like a new vitamin. Well, your memory has served you no better than most people when they look at that.

B612 was the designation, the name of the asteroid on which the little prince lived. He and his rose created by St. Exupery in his child's story, The Little Prince. You didn't read it? Well, the little prince lived on asteroid B612, and he's our hero. He was there first. The B612 crew has worked out the general concept. First, fly to the asteroid, then stop it from spinning, and finally start what could be years spent pushing the asteroid off its deadly collision course.

Much, much easier said than done. There's far more work ahead before this technique can even be tested, and they can't do it alone. NASA and a big center like the Jet Propulsion Lab would have to take on the project. We need to get this into the JPL system to do the analysis, you know, detailed analysis. While we may be professionals, we're not capable of running that kind of an analysis. So somebody needs to run through those numbers, but we believe from the work we've done that you'll find out that this, in fact, can be done on a single launch vehicle. We would also deploy a scientific package or two or three or five or whatever, much of it related to obtaining the kind of critical surface

characterization data which we'll need for subsequent missions, and in particular, the issue of attaching to the asteroid. And attaching the spacecraft to the asteroid is more complicated than you might think. It's not at all like landing on a really big body like the moon. Okay, one of the things that I want to emphasize is that we're really talking about docking with an asteroid. We're not talking about landing on it. One of the challenges we have in dealing with something like this is the mental models that we have in our head about these things. And because it's a pretty big body, even a 200-meter diameter asteroid is pretty big when you're right up next to it. But the gravity is very low.

We're talking about almost insignificant gravity here. So that when even a very large spacecraft is sitting on the surface or in contact with the surface of this asteroid, its quote-unquote weight is something less than a tenth of a pound. I mean, you hiccup and you've lifted off the surface. So you're really talking about flying up and docking with this thing. And if you keep that idea of docking in mind, I think it helps. In fact, I think in all the diagrams we do from now on, by the way, Dan,

what we ought to do is have it horizontal, never having the spacecraft on top. So let's say you've made it to your chosen NEO, or near-Earth object, and you've successfully attached your spacecraft to its surface. What kind of rocket would be capable of changing the trajectory of such a massive body? We only know of one, an ion engine powered by a nuclear reactor. And that's another place where NASA and JPL could enter the picture. NASA's new Project Prometheus has begun to develop exactly this kind of technology. It may power the Jupiter-IC Moon orbiter mission in 10 or so years, and it could also be just

the ticket for the B612 project. But the political hurdles could be bigger than the engineering ones. We're talking in Prometheus about using nuclear reactors in space. That is a big change. In the United States, putting an active fission reactor in space is going to be, when the public finally realizes what we're talking about, that is going to be a major challenge in terms of public acceptance. And unlike any other mission, this mission offers the best rationale. There's going to be a lot more NEOs that people are going to be aware of.

They're going to be concerned about them. And there is no way in which the Earth can be protected from impacting NEOs without the use of nuclear reactors to provide the kind of energy needed to deflect these asteroids. So the rationale is perfect for this public relations challenge, which is going to come up. When we come back, we'll hear how the B612 Foundation is already working to select an asteroid for testing of their deflection plan. We'll also learn why blowing the rock to smithereens with big bombs is a solution best kept in movie theaters. Stay with us.

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're about to hear more from Rusty Schweikert, Apollo astronaut and chairman of the board at the B612 Foundation, a small non-profit dedicated to developing asteroid deflection technology that might save the planet someday. The Foundation's goal is to conduct a test in space by 2015. With this in mind, they've begun using data from telescope and radar-based examinations of near-Earth objects to find just the right kind of rock,

or rather a loose collection of rocks and rubble clumped together as they orbit the sun. Here's Rusty. Okay, one of the questions that people often ask is, well, you know, are there any asteroids which, you know, what would you pick for an asteroid? Well, since we're talking here, and this is important to keep in mind, since we're talking about a demonstration of capability, what we're talking about here is the fact that people are going to hear more and more about these asteroids. They're going to become more and more concerned about the fact that we might get hit by one. Somebody ought to be doing something about it.

What we're interested in doing is to demonstrate clearly to ourselves, to the public, that human capability has now evolved to the point where we are able to protect the Earth and to protect life from this historic threat that has reshaped life many times on Earth. So it's a demonstration of human technical capability. We're not proposing to actually deflect an asteroid for any purpose other than to demonstrate that we now, humans, now have this capability. So we pick a convenient asteroid. So we're going to pick an asteroid which would be no threat to the Earth either before or after the mission. And, of course, we don't know of any that are a threat to the Earth before the mission anyway,

and we're not going to push anything hard enough to become a threat. So that's not a difficult thing, but you have to convince people that that's what you're doing. And preferably, of course, we want to pick a rubble pile, again, so that we have the worst case challenge that we're meeting. So after looking through the database, what we came up with was, I think it was 16 candidate asteroids here, which are all in the 200 meter diameter plus or minus range. We said, okay, furthermore, it happens that one of those, 2000 EH26, is also in Steve Ostro's radar database, although there's not a heck of a lot of information there, unfortunately, Steve. But nevertheless, it looks like it's a good candidate.

The point here is that there are a number of asteroids, potential asteroids. And by the time we get to flying this mission, this list of 16 will have expanded to, you know, probably 1,000. you know, probably a thousand. So why not just send up some of the biggest bombs we can fit in a rocket and use them to either blow up the asteroid or use the blast to deflect it? Dan Durda has heard the question many times. The senior researcher at the Southwest Research Institute is also president of the B612 Foundation. My favorite answer to that is that you can't mine an asteroid by nuking it.

This technology, the same technologies that we're going to be demonstrating or hope to demonstrate in this particular case to move or deflect an asteroid to protect the planet, are exactly the same technologies and capabilities and techniques that we're going to be using for moving asteroids around the solar system to mine them and utilize them for their resources. And that opens up a whole range of technologies and capabilities that, you know, if you go out and blast an asteroid, you can't do that. Two other answers to that are that, as we have emphasized in the talk, we really do not understand the structural characteristics

of these near-Earth asteroids, or any asteroids for that matter. We do know that they're very porous from the work that Steve and others have done. Their specific gravity is like two instead of what you're used to here, four or five or whatever for things on the Earth. So that we know that they absorb tremendous amounts of energy. When you look at some of these asteroids, pictures of them, you see huge craters. In other words, a big thing has hit it, and yet it's just made a big, soft hole. It's like hitting a marshmallow.

Or, for that matter, think about skiing down in fresh powder and then making a belly flop. You make a big hole in it, but you don't move it very much. So we don't know what a big hole in it, but you don't move it very much. So we don't know what a nuclear explosion would do, and as a result, we can't predict what the result would be. It may actually simply split an asteroid in two, and then we end up with two problems instead of one. We just don't know. Secondly, when you think about this, you're talking about a long-term problem.

This is not something which happens every year, every hundred years even. A thousand years it may not happen that you want to deflect one. So the question is, do you want a technology which is benign and which is useful for many other things as the way in which you handle this challenge? Or do you want to have nuclear weapons sitting around in the hands of who knows who for thousands of years standing by for this? The cure may very well be worse than the disease. In fact, I guarantee it would be.

It's at least somewhat comforting to know there is a group like B612 that is not just looking for asteroids with our name on them, but figuring out what to do when we find them. But what about government? Isn't there some agency working on this? NASA? The European Space Agency? The EPA? Homeland Security? The Post Office,

for goodness sake? No, there is no agency. There is no real activity. If you look at these papers, there are three papers that I've written on exactly that issue, what might be called the governance and legal issues associated with deflection. That's a separate issue from what we've talked about today. Although you'll notice that in NASA's charter, there are the words to protect the planet. Okay, but at least some governments are working to identify and track the thousands upon thousands of undiscovered NEOs. Britain is a leader in this area. But what would a more comprehensive search cost?

Once again, here's Rusty. It's not very expensive. The JPL report, the science definition team report on NEOs, which I recommend that you take a look at, frankly, on NEOs, which I recommend that you take a look at, frankly, has looked at this whole issue and made cost estimates of what it would take to discover 90% of the near-Earth asteroids down to 140, I think was the number you guys used on. There are a number of ways you can do it, ground systems or space systems. But that, if you put, for example, a telescopic space system in a Venus-type orbit, that gives you a fairly rapid discovery rate for asteroids in this class. And the cost is something like $380 to $400 million.

It's not a lot of money to provide that level and quality of information in a timely way. The fact of the matter is, out to some number, pick five Earth radii arbitrarily, okay, out to five Earth radii, we're not going to be able to tell until the very last few years at best whether in fact it's going to miss the Earth with a near miss or whether it's going to impact. So for decades, we're going to have these things with a long list of objects which look like they might hit the Earth. And the public is going to, these guys put everything out on the web right away. They're wonderful, transparent people.

And so the public is going to be right there, and the press is going to grab every bit of it to hype it and mischaracterize it. So far, the pay for saving the Earth is pretty lousy. And trying to get government agencies to put a few hundred million dollars into your pocket can be frustrating, especially when you can't just point to a light in the sky and say, that one is going to wipe us out in a few years. So what keeps them going? All of us who came together in that October

meeting at Johnson Space Center four years ago now or something like that were there because we were knowledgeable about, involved in near-Earth objects and understood that there's a tremendous number of objects out there. The frequency with which we're going to be discovering them is going to rapidly increase over the next several years. The public is going to become very aware of near-Earth objects whizzing past the Earth and with the potential of hitting the Earth, and yet no one really was doing anything about taking action. And we all felt that the whole issue of deflection needed to have somebody actually working it as a serious issue. And so we came together to wrestle with whether or not we were ready to do that.

We ended up deciding we would. The B612 Foundation is willing to support NASA in any way we can, either as individuals or as a technical advisory team or, frankly, as nothing. I mean, we'll dry up and blow away. We'd hand it over to you. We would love NASA to pick this up and run with it. And, in fact, it needs to be evaluated and given the same level of analysis, the comparable level of analysis of other alternative Prometheus missions.

But when we discover one of these things actually on an impact trajectory, there will have to be a decision made. That's a public policy issue, which is another dimension of this whole issue of neo-deflection. Do we simply let it hit and evacuate wherever we believe it's going to hit, or do we go up and deflect it? That's a decision which someone undefined right now will have to make. which someone undefined right now will have to make. B612 Foundation Chairman Rusty Schweikert at the Planetary Society earlier this month. You'll find a link to the foundation at planetary.org slash radio.

I'll be back with Bruce Betts and this week's What's Up, right after Emily tosses a few more rocks of her own. I'm Emily Lakdawalla, back with Q&A. Even though the asteroid belt is very sparsely populated, that doesn't mean that collisions between asteroids are impossible. Collisions are rare, to be sure, but when you consider the age of the solar system, over four and a half billion years,

it turns out that such rare events are quite likely to happen. The asteroid belt is located relatively close to the orbit of the giant planet Jupiter, whose gravitational influence is constantly nudging the asteroids into slightly different orbits. Over time, these nudges have caused asteroids to form bunches and clusters. If any wayward asteroid's path took it through such a cluster, collisions could happen.

Still, chance favors the safety of objects crossing the asteroid belt, which is good news for Earth's attempts to explore the outer solar system. To date, six spacecraft have safely traversed the asteroid belt. Two Pioneers, two Voyagers, Galileo, and Cassini. Let's hope that Earth explorers are never so unfortunate as to win the lottery of chance asteroid impacts. Got a question about the universe? Send it to us at planetaryradio at planetary.org. And now here's Matt with more Planetary Radio. Time for What's Up on Planetary Radio,

and we are rejoined by Dr. Bruce Betts, the Director of Projects for the Planetary Society, and you played host and emcee for that event that was held here with the B612 Foundation that we featured on today's show. That went really well. Yes, it did. We were very pleased with it, and we've just established a partnership with the B612 Foundation that we featured on today's show. That went really well. Yes, it did. We were very pleased with it, and we've just established a partnership with the B612 Foundation, so we're excited moving into the future.

And I know I'm going to be impressed with what's up today. Oh, I know you will, Matt, because, you know, how can you not be? I am Gideon Giggly today, because we've got all the planets, all the planets you can see with your naked eye. Or with your eye behind clothing. Well, no, probably not. Okay. That's why they call it naked eye.

I get it now. Alright, I don't feel as embarrassed about it. Five! Five naked eye planets exist and all five of them will be viewable simultaneously starting around the 16th, 17th, 20th, 18th of December, something like that, as soon as Mercury pops its little head up over the horizon. Let's start in the pre-dawn.

Well, first let's start in the evening sky where you've got one planet, but it's a cool one, Saturn. And Saturn is visible rising about an hour or two after sunset in the east. And it is hanging out in Gemini with Castor and Pollux, two bright stars there, but it's brighter than the two, and so you'll see a line of three star-like objects all looking bright. The lowest one, the brightest, is Saturn. In the pre-dawn sky, where all the planets are partying,

you've got Saturn hanging out way over in the west, kind of lonely and antisocial, but over there in the east, you'll see Venus being the brightest star-like object there, extremely bright. Jupiter also very bright to the upper right of Venus. Mars, which was nuzzling Venus just a few days ago, is now growing farther apart from Venus, going to the upper right of Venus. Venus going to the upper right of Venus. Meanwhile, Mercury poking its head up on the low on the horizon, the lower left of Venus coming up to play with Venus. And Venus and Mercury will be doing a little dance for the next month or so.

Did we already make the joke about Mercury sort of being the Kilroy of the solar system peeking up over the horizon? No, I don't believe we did. Well, we have now. We have now. Oh, that was it. Mercury is sort of the Kilroy of the solar system. Okay.

Well, Mercury will be here coming soon, and you'll be able to see Mercury. It's always low down there on the horizon, in this case in the southeast. It'll keep rising up over the next week or two, and as I say, get very close to Venus. It'll stay within a couple degrees of Venus from mid-December through mid-January. Terrific. Cool. And you might note, as you follow, you can draw a line through these planets, and they're almost lined up in a line because they all orbit nearly the same orbital plane.

So if you think about it, that's why they're all lined up. On to this week in space history. December 14, 1972, Gene Cernan on Apollo 17 becomes the last astronaut to walk on the moon. Heavy sigh. On to Random Space Fact! Mars' moon Phobos, as seen from the surface of Mars, rises in the west and it passes overhead three times a day. That's kind of funky. Yes it is. That's kind of funky.

Yes, it is. It's got about an eight-hour orbital period. Zipping around the planet. Whipping around that planet. Just whipping around. And Phobos is going to come up again next week, because it's the topic of our trivia contest that we'll be answering next week. It is indeed. Phobos.

Speaking of trivia. Speaking of fear, on to the trivia contest. We asked you about orbital resonance. For example, the Earth's moon is in a one-to-one resonance. Its day is the same length as the time it takes to go around the Earth, so it keeps one side facing Earth at all times. Mercury is also in an orbital resonance. What is it? That was the question, which is basically asking,

what is the relationship between its year to the length of its day? How'd we do, Matt? As usual, lots of entries, lots of correct entries. We are getting a bigger response than we used to, which either means lots more people wanting to win a Planetary Radio t-shirt or a lot more people listening to the show. Both, I hope. And you want to know who our

winner was oh i do i do it was and we're going to use he's asked us to use his nickname messa uh marek smegen smegen smagen sorry about that we'll just stick with messa messa is uh from the czech republic he came up with the correct answer mercury has a 3 to 2 spin orbit resonance. That is indeed truth. There are three Mercury days in two Mercury years. So its year is about 88 Earth days long, and its day is about 58, 59 Earth days long. So we're going to slap a little more international postage on another Planetary Radio t-shirt and get it out to the Czech Republic. Slap it on.

And here's your chance to win. Not next time around, because, you know, we wait a couple of weeks before we actually name the winner of the current contest. And here's Bruce with that right now. What asteroid will the Japanese Hayabusa mission, formerly known as Musa C, tried to sample in 2005. And how did they enter? Go to planetary.org slash radio. Follow the links for the trivia contest. Learn how to send us your answer.

Tell us about that asteroid. What is it called? Where are they going? Tell us. When do they need to tell us by, Matt? By Monday. I'm not going to do that. I hate that.

Monday, December 20th going to do that. I hate that. Monday, December 20th at noon Pacific time. Monday, December 20th noon Pacific time. Oh, God, it's got me by the throat. Don't resist, Matt. Join us. Be there. It's the demon of AM radio.

I'm sorry. We better get out of here. Okay, everyone go out there. Look up in the night sky and think about soothing deep voices. Thank you and good night. How right you are, Bruce, the director of projects for the Planetary Society, who joins us each week here on Planetary Radio. We're out of time. Thanks very much for listening and have a great week.