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Cosmic Coincidence: Asteroid Careens by as Meteor Delivers ‘Buzz Cut’ to Earth

February 15, 2013 at 12:00 AM EDT
On the same day as a meteor hit Russia, an asteroid careened towards Earth. Jeffrey Brown talks to astrophysicist Neil deGrasse Tyson about this cosmic coincidence, how the meteor and asteroid came so close to Earth, what risks it poses and why this is a 'wake-up call.'
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JEFFREY BROWN: Scientists say the meteor weighed about 10 tons. And in what’s being seen as a cosmic coincidence, it came on the same day as an asteroid that came exceedingly close to Earth, at least in space terms.

As this NASA animation shows, the asteroid was just over 17,000 miles away from Earth, traveling at about eight miles per second, actually inside a ring of television and weather satellites that surround the planet. Nicknamed DA14, the asteroid was half the size of a football field.

It passed, we can happily report, without incident. 

And here to tell us about both events is astrophysicist and author Neil deGrasse Tyson, director of the Hayden Planetarium in New York City.

Welcome to you.

Let’s start with what happened in Russia. How unusual was that in terms of size and impact?

NEIL DEGRASSE TYSON, Hayden Planetarium: Well, we don’t know precisely how common that would be. All we can do is sort of look back at other sort of reported such events.

For example, there was an air blast that happened in the airspace over India and Pakistan back in the 1990s which happened to occur while they were in intense conversations about their nuclear buildup of armament. And so such a blast mimics greatly what would happen with a nuclear blast. It is an instant deposit of energy in the atmosphere.

And so, fortunately, we were able to tell them — we, I mean people, my scientific brethren who study this — we were able to tell them, no, that wasn’t somebody’s first strike. It was actually a cosmic event. And so that was in the 1990s.

And if this had happened over the Pacific, nobody would have noticed.

JEFFREY BROWN: Is it, in fact, happening all the time, this kind of thing?

NEIL DEGRASSE TYSON: Yes, so — yes, so something of this magnitude we might imagine is perhaps once a decade. I mean, if one happened in the 90s and one happened now, and you fill in for the areas of the Earth where it wouldn’t have been noticed if it did, for example, the North Pole or Antarctica or Northern Canada, where hardly anybody lives, you could easily sort of hide one of these from anybody’s view simply because of the large swathes of area on Earth’s surface where nobody inhabits it.

So I could imagine it would be once every five to 10 years.

JEFFREY BROWN: And what exactly is it? What is a meteor and what is an asteroid, for that matter?

NEIL DEGRASSE TYSON: Yes, well, OK, we can go back, yes, asteroid 101.

In the solar system — actually, I have the solar system on my tie. This is not drawn to scale, but you have your sequence of planets going from Mercury all the way out to Neptune. And between Mars and Jupiter, there’s a swathe of countless chunks of craggy rock which we call the Asteroid Belt.

Now, a subset of these have wandered from their belt — we call it the main belt — and have orbits that bring them dangerously close to Earth. And we have collectively described them as near-Earth objects. You can call them near-Earth asteroids as well, but we want to include in there comets that might come near us that perhaps don’t begin their journey from the Belt.

And so there is tens of thousands of objects that are dangerous, as dangerous as what we saw this morning in Russia, that — whose orbit crosses the orbit of the Earth. Now we cross the street all the time, the same street that trucks drive on, but we’re not hit by trucks because we’re not there at the same time and the same place.

If you do the math, it turns out that eventually Earth and anything that crosses our orbit will collide with one another eventually. So these are the ones we want to keep track of. The problem is the little ones — the one in Russia was a little one by cosmic standards. They’re so tiny you can’t see them until it’s too late.

JEFFREY BROWN: That brings us to that asteroid 17,000 miles away. That was — how unusual is something like that? How much — in your scheme of dangers, how dangerous is something like that?

NEIL DEGRASSE TYSON: Well, in the past decades, we have gotten better and better at monitoring asteroids that kind of invade our space, if you will.

And up until today, we would — you know, the invaded space criterion was, does it come closer to us than the moon? The military now calls that cislunar space. It was a new word to me even just a few years ago.

Cislunar space is the region between us and the circle that is the orbit of the moon. And so we have been monitoring asteroids that have sort of been whizzing by in that zone for at least 10 or 15 years. This is the first one that has come so close that it is in fact 5,000 miles closer than our orbiting communications satellites, the geostationary region around which perhaps even this television signal is being sent around the world.

So that would — that is cause to sit up straight and raise your eyebrow and say, now, wait a minute, and now add that to the Russian air blast this morning, and you have got a situation where astronomers have been telling — the whole astrophysics community has been telling people about this for decades.

And maybe it takes an actual event. Fortunately, from what we hear, I don’t know that anyone died in that event, just a lot of damage and cut faces and hands. But if it takes such an event to wake people up that Earth moves in what is indistinguishable from a shooting gallery in the solar system — these are debris of rocks left over from the formation of the solar system. And it used to be sort of …

JEFFREY BROWN: And …

NEIL DEGRASSE TYSON: Yes, go on.

JEFFREY BROWN: Well, I was just going to ask you, as a wakeup, then what? I mean, what would be possible to do? Create a warning system?

NEIL DEGRASSE TYSON: Yes, exactly.

So this is really a shot across our bow. Both of them were. Right? Well, one of them actually hit us, at least burst into the atmosphere. The other one is like — is a buzz cut to Earth. And you can say, well what do you do about it?

Well, if you live in a world without scientists and engineers, the first thing you do is, you say, let’s run or hide or buy water and dig holes and live in them. But we live in a technologically fluent culture, whether or not everyone shares in that fluency. And among those who know, we have ways, on paper, to deflect asteroids if we find them early enough before they come in.

None of those plans are funded by any agency anywhere in the world. So that’s a whole other cultural political challenge that would need to be overcome. For the moment, all we’re doing with the meager funds that NASA has to do so, and combined with some other funds around the world, is to just find the asteroids and track them.

Now, this one that hit Russia, yes, it tore up the town a bit, but it’s not disrupting civilization. If you get asteroids about a kilometer in size, those are large enough and carry enough energy into our system to disrupt transportation, communication, the food chains, and that can be a really bad day on Earth.

And so we set up a criterion to find all kilometer-class asteroids whose orbit crossed Earth, and we did a really good job at it. We said, OK, let’s go a little smaller. How about — how about 100-meter asteroids? Let’s map them. Now we know when they’re coming, but we still have no means to do anything about it.

JEFFREY BROWN: All right.

NEIL DEGRASSE TYSON: Now, the little ones, the one that hit Russia, those will show up hours before they hit, and that one showed up just in the image. Maybe the military had a slightly earlier bead on it, but nothing that — you are not going to evacuate a town in the time available.

JEFFREY BROWN: And, of course, there were early and sort of obvious questions about whether there was a link between what happened in Russia and the asteroid that passed by. But it just looks like a strange coincidence?

NEIL DEGRASSE TYSON: Yes, just a cosmic coincidence, but, sure, that’s your first thought, until you notice that they had completely different trajectories through the solar system.

And there is a chance they could have had the same trajectory. And if they did, then you would worry whether there would be other — to meteors in between that would come in line and hit us between those two events.

No such thing happened, just a cosmic coincidence, and we should be glad for that.

JEFFREY BROWN: A big day in space, and a lot to think about.

Neil deGrasse Tyson, thanks so much.

NEIL DEGRASSE TYSON: Thanks for having me on.

JUDY WOODRUFF: You can see the spectacular video of the meteor falling from Russian skies, and learn more about the science of meteors and meteorites. You can find a link to that on our home page.