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CORVALLIS, Ore. - Every day, billions of Earthlings go about their business, blissfully unaware that a large asteroid or some other massive space object may cascade out of the sky and blow them out of existence.

A small group of scientists, meanwhile, sizes up the threat and works on a strategy to prevent us from going the way of the dinosaur.

Sounds like a Hollywood script, right? When "Armageddon" hit theaters in 1998, the Bruce Willis-led cast garnered a fair amount of attention, but little scientific credibility for its plot to send a crew of oil drillers into space to plant a nuclear bomb on an incoming asteroid. Yet scientists are indeed constantly looking at the threat of "near-Earth objects," or NEOs, and figuring strategies to prevent an Armageddon-like catastrophe. Nuclear bombs are the likely weapon of choice.

And an Oregon State University honors student is working on the project with them.

J.C. Sanders is a senior from Roseburg, Ore., who is majoring in physics in OSU's University Honors College. After spending a summer working at the Los Alamos National Laboratory, he applied for a summer job at the Lawrence Livermore National Lab in California, where he hooked up with astrophysicist Aaron Miles on the project.

And yes, Miles says, the threat is real - even if the odds are long that it will happen in our lifetimes.

Miles points to research conducted by David Morrison, Clark Chapman and Paul Slovic, published in "Hazard Due to Comets and Asteroids," which found that the Earth is struck by objects about 100-meters in diameter every 1,000 to 5,000 years. Equal to the explosion of the largest nuclear devices, they could destroy a major city.

Every 15,000 to 60,000 years a 500-meter NEO strikes, which can destroy an area the size of a moderate state and create massive tsunamis with long-lasting effects. And every 250,000 years or so, objects as large as one kilometer in diameter strike and have global consequences, destroying an area the size of France or larger, and raising huge quantities of dust that can alter climates, or cause extinctions.

Scientists have their eye on these NEOs and believe they can predict when they most likely may come into Earth's orbit. And that is a bit of good news, Miles said.

"NEOs up to a few hundred meters across could realistically be destroyed or deflected with as little lead time as years to decades," Miles said. "Objects up to a couple of kilometers could probably be reliably deflected if discovered decades before impact. For objects 10 kilometers or greater - like the one believed to have done in the dinosaurs - you might as well dig yourself a nice deep hole to hide out in.

"And don't worry about an escape tunnel," he added, wryly, "because your hole will not be deep enough to save you."

The deflection strategy is where Sanders comes in. A 2002 graduate of Roseburg High School, Sanders is studying the how much energy a nuclear device - detonated a few hundred meters from an asteroid - would actually transfer to the asteroid and move it in the right direction. The idea isn't necessarily to blow up the object, he pointed out. It's to knock it out of Earth's orbit.

And that takes a lot of energy, he says.

"When you hit a NEO with a nuclear device, it quickly heats the outside layer, which ablates - or blows off," Sanders said. "The explosion travels in one direction and pushes the asteroid in the other. It's like a huge, temporary thrust. That change in velocity is the key, because if you sufficiently change the speed or direction of the NEO, combined with the sun's gravity, it will miss the Earth."

Sanders' specific part of the project is to study how much energy from a nuclear device would be deposited into the asteroid, how much is used for heating, how much is lost to melting the ice, and how much is deflected.

The work is all done by computer models, but small variables can mean significant differences in the outcomes. And all NEOs aren't created equal, he said.

"Most asteroids and comets aren't perfectly round, they are more complex," Sanders said. "If they were perfectly symmetrical, it would be easier to determine the best place to hit them to create the most energy. Many of them are pock-marked, from being hit by mini-asteroids, so the surface is uneven.

"And they aren't necessarily solid," Sanders added. "They may be partially composed of gravel or rubble, which means they could have gaps or pockets of gas inside. If you push on a cement block, you can usually move it. If you push on a pile of gravel, it's more difficult."

There's a lot more to the research - the ratio of photons to neutrons, alternative solid projectiles, orbital variations and the like, but it takes a rocket scientist to understand it. And there is a whole other world of classified information to which Sanders doesn't have access.

Nevertheless, the OSU honors student is enjoying the experience and hoping the research remains theoretical. Miles, though, says it is just a matter of time.

"J.C.'s project is a good one in that it incorporates several branches of physics and applies them to a problem that not only is intriguing, but also will at some point in the future become the most topical of issues," Miles said.

"When you consider the hazard per impact and the impact frequency, some researchers have argued that, for U.S. residents, your chances of dying as a result of an asteroid collision are greater than your chances of dying from other natural disasters - because so many people could be killed in a single incident.

"But unlike those other disasters," Miles said, "we might actually be able to do something about a pending impact."