Scientists Gather at Conference to Stop Asteroids
ALEX CHADWICK, host:
What if a giant meteor is heading toward Earth and is going to crash into our planet? This sci-fi plotline plays out today at a conference in Washington, called to figure out what to do if such a thing really happens. We're joined by the chair of the Planetary Defense Conference, William Ailor. Mr. Ailor, welcome to DAY TO DAY, and how real is this threat?
Mr. WILLIAM AILOR (Chairman, Planetary Defense Conference): It's a small threat. I mean these things happen very rarely, but it is a sure thing that it will happen sometime. And basically that's what the conference is about, is to figure out what do we do.
CHADWICK: You know, there are various sizes of things that might crash into Earth. How likely is it do you think that an object big enough to really do some damage would hit us?
Mr. AILOR: Some people think that they haven't happened before, but they actually have. We had one called Tunguska that hit in 1908. That was about a 50-meter sized asteroid or comet, and it leveled about 500 square miles of forest.
CHADWICK: And where was that?
Mr. AILOR: That was in Russia, in Siberia, and fortunately there was nobody around, but that would have really caused a lot of damage had it hit a populated area.
CHADWICK: All right, well, if you could find these objects, then what might you do?
Mr. AILOR: Well, if we found one, the first thing to do is to make sure it really is a target - targeted at Earth, and that's part of the problem again, there's uncertainty in measurements. So you have the fact of those in, have to take measurements over a long period of time. But if we actually found one that was targeted for Earth, then we need time.
Time is really critical for doing asteroid deflection, so you need to have a fair amount of time to actually build a rocket or build a deflection system, whatever that might be, and actually get it out to the asteroid and have it act on the asteroid.
CHADWICK: This sounds so much like the plot of the movie "Armageddon" with Bruce Willis. They don't have much time, three weeks or something. They got the rocket, they go up with the bomb. I mean is that the kind of thing that you're talking about, go blow up the asteroid?
Mr. AILOR: Well, blowing it up is not the result, typically. I mean there are several options that people have considered. One is called - something called a gravity tractor, where you fly a heavy spacecraft next to an asteroid and over a period of months to maybe a year or more you actually - the gravitational attraction will slowly nudge the asteroid off its track.
There are other approaches. You could explode a nuclear device next to an asteroid or on an asteroid, or you can use a kinetic impactor, which is one where you simply run into the asteroid with a heavy spacecraft. Again, if you catch a spacecraft well away from the Earth, and you can just touch it and just give it a very small velocity increment, and that would be enough to keep it from hitting us.
CHADWICK: Didn't NASA try something like this a couple of years ago, something called Deep Impact? Didn't they try to hit an asteroid with a rock? How did that go?
Mr. AILOR: It went very well. They actually did hit it, and that is an example of what we call a kinetic impactor; that was a small spacecraft relative to what we need to do for an asteroid. But it was a small spacecraft and it really demonstrated the capability of finding one of these things and hitting it with a body at a relatively high speed.
And so all of these, you know, what you're looking for is something that would actually cross the Earth's orbit. And you know, we have an asteroid that, as they say, the poster child of these, it's called Apofiz, which is due to make a close approach to Earth in 2029. And then if it comes right through the right spot would actually come back and hit the Earth in 2036.
CHADWICK: And if that hit the Earth, how much damage would it do?
Mr. AILOR: Well, that's one of the things we'll be talking about at the conference. I'm sort of waiting myself to hear what some of the experts say at the meeting in the next couple of days.
CHADWICK: William Ailor, director of the Center for Orbital and Reentry Debris Studies at the Aerospace Corporation, which advises the government on technical questions about space; and he's the chair of the Planetary Defense Conference meeting in Washington. Mr. Ailor, thank you.
Mr. AILOR: Thank you, Alex.