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Is Asteroid 2012 DA14 a threat to Earth? Q & A (VIDEO)

GlobalPost talked to an asteroid researcher from MIT about Asteroid 2012 DA14, Hollywood disaster movies, solar sails and gravity tractors.

Meteor crater nasa earth observatoryEnlarge
Meteor Crater in Arizona formed from the impact of an iron-nickel asteroid about 46 meters (150 feet) across. (NASA Earth Observatory/ National Map Seamless Server/Courtesy)

UPDATE: What is thought to be a meteorite exploded over Russia on Friday morning, injuring hundreds of people and shattering windows in a remote region of the Ural Mountains. GlobalPost asked Richard Binzel, a professor of Planetary Science at Massachusetts Institute of Technology, to clarify if the event was related to the asteroid that will fly by Earth on Friday.

Binzel said: 

The Russian event, surprisingly, appears totally unrelated. The Russian meteor was from a mostly north-to-south trajectory. Asteroid 2012 DA14 passes by today, moving the exact opposite way; South-to-North. Orbital physics (orbital angular momentum) simply cannot have two objects in opposite directions being related.

The Russian object was probably about 2 meters across, about the size of an SUV. 2012 DA14 is 50 meters across, or about half the size of a football pitch.

Follow our live blog for updates on the incident in Russia.

You can watch the live video of the asteroid flying by Earth here:


Live broadcast by Ustream

The original article is below:

You might have heard about the asteroid that's going to have a close shave with Earth on Friday.

Asteroid 2012 DA14, as it's officially known, is set to pass by Earth on Feb. 15 at a distance of 17,200 miles, closer than some satellites orbiting our planet.

The 143,000-ton asteroid is 50 meters wide, or roughly half the size of a football field, and thought to be made of stone (as opposed to minerals or metals). 

If the news calls up images of "Armageddon" or "Deep Impact" in your mind, have no fear, we're safe this time.

GlobalPost talked to Nicholas Moskovitz, a postdoctoral fellow at the Massachusetts Institute of Technology's Department of Earth, Atmospheric & Planetary Sciences, about flying space rocks, Hollywood disaster movies and some of the more far-fetched ideas out there to defend the Earth against asteroids.

How are we so sure that Asteroid 2012 DA14 won’t hit Earth?

Given enough time we can observe this object over and over again and we can pin down its orbit. If this object’s orbit intersected the Earth’s we would have to worry, but it does not, so we’re perfectly safe. We’ve been able to define its orbit so we know it’ll pass at a safe distance.

It’ll come close, unusually close for an object of its size, but it’s no immediate threat to the Earth.

We discovered the object last year, last February. These objects are given these phonebook designations right after discovery. That tells you when the object was discovered. [In this case, the 2012 in the asteroid’s name.]

Typically these Earth flybys are discovered hours or maybe days before they fly by. This one is pretty extraordinary because it was discovered a year before the flyby, which gave us plenty of time to plan for this event.

Chances are it’s probably experienced some other close encounters with the Earth in the past. It’s quite possible the asteroid passed us decades ago, much closer.

Its orbit is going to be changed by its close encounter with the Earth, sort of like a slingshot effect. It’s going to come in close and get slungshot away.

But, we’re perfectly safe from this one.

More on Asteroid 2012 DA14 from Science@NASA:

Now that we know we’re safe from this one, what would happen if an asteroid of this size hit the Earth?

This asteroid is getting up to the size that maybe you should be a little bit concerned. I say that because it could do significant localized damage.

This asteroid’s something like 40 or 50 meters across. An object that big is not going to cause any sort of global fallout or destruction, but it could do significant localized damage. If one of these objects happened to fall on a major metropolitan area, that would be a problem.

Meteor Crater in Arizona (which is 50,000 years old) is a good reference for an asteroid of this size. It’s an impact crater that’s about three quarters of a mile across, and the impact that made that crater was probably about 50 meters across.

The other impact from a similar object, but slightly larger, would be the Tunguska impact, which happened in the early 1900s. An asteroid slightly larger than DA14, probably around 100 meters across, exploded in the atmosphere over Russia. That caused significant destruction over something like 800 square miles. It scorched huge swathes of the Siberian wilderness. There are some interesting first-hand accounts of people getting blown off their feet and windows getting blown out.

How would any country defend against an asteroid? Are there any plans in place?

This is very much a hot topic in the community right now. There are many ideas out there, but they all depend on how much time we have. If we detect an object five years before impact, there’s a very different mitigation strategy than if we detect an object two weeks before impact.

What are some of the more far-fetched ideas out there?

You’ve probably seen "Armageddon." That is one of the far-fetched ones. That one, I’m not sure is a good idea.

Blowing up these objects... If you have an object heading towards Earth and you decide you’re going to blow it up, now instead of having a single impactor, you have a thousand impactors distributed over a much wider area. I don’t know if that’s necessarily a good idea.

If you have enough time, there are lots of ways to deflect these things from their orbits, to push them away.

There are solar sails, where you can use the pressure from solar radiation to push a sail which would cause the object to drift off course. Attaching a sail to the asteroid could allow a solar wind to push the object off its orbit.

There’s an idea people refer to as gravity tractors, which is the idea that you would park a spaceship next to the asteroid and let it stick next to the asteroid over a long period of time. The asteroid would be gravitationally attracted to that spacecraft in small amounts. If you do that long enough, you can actually deflect the asteroid and move it off course.

Those all sound like long-term plans for when we have advanced warning.

Exactly, those are definitely ideas for long-term plans. I don’t think there’s actually an official plan – at the highest levels – in place, for what would happen if we discovered something tomorrow. There would be a lot of scrambling. It would have to be an internationally coordinated effort.

There are programs being talked about in NASA and European space communities to test out these techniques. Go out to an asteroid that’s harmless and poses no threat and see if we can move it around in its orbit and see how fast we can do that. I think that’s worth trying.

These are relatively cheap missions and I think the technological demonstration on whether we can or can’t is pretty important to help us prepare for such an event.

What do you think of Hollywood’s portrayal of asteroids?

It’s entertainment and it’s meant to be exaggerated. I know entire college courses can be taught about all the mistakes that are made in Hollywood from a technical or scientific standpoint. Movies are not meant to be technically accurate.

I actually think a lot of the things that were done in the movie "Deep Impact" were well done. They did a decent job, and they didn’t stretch the truth too far. They are sensationalized. It’s not meant to be accurate, it’s meant to be entertaining.

The impactors you see in those movies are a kilometer, multi-kilometers wide. We know of all the objects out there that are that size, and we are in no danger until deep into the distant future of being hit by anything that big.

The thing we still have uncertainty about is objects the size of DA14.

We know about all the big objects. We don’t know about all the small objects. There’s still a lot of discovery to be done, to make sure we’re safe from them.

There are at least two companies (Planetary Resources and Deep Space Industries) that have proposed asteroid mining. Is it at all plausible?

People have been discussing this since asteroids were discovered. What’s really unique about this time is that space is becoming increasingly commercialized. You have private companies doing regular trips up to the space station. It’s a revolution of sorts.

Space is no longer the exclusive domain of governmental agencies. You have this privatization of space that’s making it accessible and cheaper to get to lower orbit.

[Asteroid mining] is more plausible now than ever before. I’m optimistic, partly because I think there’s interesting science that will come out of these ventures. They’ll end up bringing asteroids or pieces of asteroids back to Earth. (Planetary Resources, for example, views asteroid mining as a way to collect precious resources such as water and platinum.) The progress or the technological development that will have to take place to start up these mining operations will be extensive. There will be a lot of technological breakthroughs to make this happen, which is a positive thing.

Within our lifetimes, we’ll see whether this pans out or not.

This is an exciting time for asteroid science and asteroid exploration in general. We have asteroid mining companies talking about going up to these things. We have NASA and the Japanese and the Europeans sending missions to these asteroids over the next ten years or so. We have the possibility of actually sending a human to an asteroid and landing on one. It's a golden age for exploration of these bodies.

This interview has been condensed and edited for clarity.

http://www.globalpost.com/dispatch/news/science/130207/asteroid-2012-da14-flyby-earth-q-and-a