There's really nothing to worry about. These guys have got it handled. All they need is to convince Congress they need $500 million and the international community to agree on which direction to go to push a hurtling asteroid off its path of fiery Earth annihilation.

These guys are a loose association of scientists, including a retired astronaut and many work for NASA's Jet Propulsion Laboratory. Together they study the risk of an Earth impact from an asteroid big enough to do damage, you know, like the one that caused all the dinosaurs to become extinct.

Only they don't call it an "asteroid" -- instead they use a more general term: Near Earth Object (NEO). They concentrate on anything bigger than 140 meters across (but mostly worry about the ones at least a mile across) and traveling on a trajectory that brings them within 4.6 million miles of the earth. They're watching, calculating and ready to do something.

These scientists have recruited observatories like Arecibo in Puerto Rico and telescopes in Hawaii and Arizona. They use radar, honed to resolutions down to less than 10 meters to precisely image the surfaces -- looking for places to land.

Now, don't conjure up the movie Armageddon for this one; they're not talking exploding the asteroid or even using a nuclear device to deflect it. These are sensitive guys with a far gentler plan -- live and let the icy-rock-of-space-death live. Plus there is too big a chance the asteroid would just reassemble -- gravity bringing the pieces back together in space and continue on its merry way.

They will, however, show you a simulation of the 15 square kilometer tower of fire that happens when an asteroid hits. And show you the piece of asteroid-impact-melted-Libyan-desert that was carved into a scarab for King Tut.

Instead, they propose to just nudge the errant little planetoid thing. Push it a little bit faster or perhaps a little head-on bump to just slow the thing down a bit -- essentially they want to play bumper cars with asteroids; just to persuade them not to hit the earth as a 200,000-megaton fireball plus cataclysmic shock wave. We're not talking about the puny atmospheric fireball like the one that leveled 800 square miles of trees in Tunguska, Siberia in 1908. That was just a little guy -- maybe 40 meters across.

All we really have to do is detect the next dangerous NEO early. Say, ten years or so. Although there is no guarantee we'll get that much notice, the earth doesn't appear to be threatened by any asteroids from deep space for now.

As the scientists describe it, catastrophe is just a matter of bad timing and three-dimensional space. There is only a tiny point in space and time where the orbits of the Earth and any of these near earth objects might meet. Then it comes down to whether or not they get to that point at the same time -- move either one a little faster or slower and, whoosh, just a close call.

There are a lot of NEOs and these are only the ones we know about. Some 6613 have been identified, of which 800 are bigger than 1 kilometer across and about 146 are identified as PHA's ("potentially hazardous asteroids," a.k.a. "near-earth-objects-that-can-kill-us-all").

Wonderfully, there is a lovely web site called Asteroid Watch that cheerfully keeps you updated on just which one is just about to get us. You can even have this information a tweeted to you. As Don Yeomans put it, "Nothing is held back." They are happy to let us know which asteroid, say Apophis, Tootatis, Castelia or Golevka, has your and my name on it.

But really, it is hard for me to tell what is more impressive, the scientific handle these scientists have on the whole fiery ball of death from space thing or their supreme confidence that, given the resources, that they can so completely handle it.

As retired astronaut Rusty Schweickart put it: "It's simple, really, we can do this."
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A guest article from science writer and veterinarian Cynthia Mills, who is currently attending the AGU 2009 Fall Meeting in San Francisco, Calif.