Sunday, August 25, 2013

Is ‘Armageddon’ coming? NASA’s asteroid hunter Don Yeomans won’t miss a thing

PASADENA, Calif. — At first glance, Don Yeomans looks like your friendly suburban neighbor. But behind the calm and cool exterior, the NASA scientist has one of the most important jobs imaginable: finding the galaxy’s deadliest asteroids before they pose a threat to all life on Earth. The prevailing view among scientists is that a giant asteroid hit the Earth about 65 million years ago, wiping out nearly all life, including the dinosaurs. And according to many of those same experts, it’s only a matter of time before another extinction-level event occurs.

Thankfully, the world is being kept safe by Yeomans, NASA’s very own asteroid hunter.

Yeomans, 70, who was recently named one of Time Magazine’s 100 Most Influential People Alive, told Yahoo News about the science behind asteroid hunting, how he finds them and NASA’s plan to make sure the “big one” never makes it to Earth.

In the 1998 film “Armageddon,” NASA discovers that a Texas-size asteroid is headed straight for Earth and we only have 18 days to stop it. So how does that scenario compare to reality?

“Well, that movie was definitely pure fiction,” Yeomans told Yahoo News in an interview at NASA’s Jet Propulsion Laboratory in Pasadena.

“First of all, there aren’t any asteroids in near Earth space that are anywhere near the size of Texas. And if there were, we would certainly find it decades, perhaps even 100 years, in advance of any close Earth approach,” he said.

For years, Yeomans has led NASA’s efforts to detect these so-called near Earth objects. He says they’ve found about 95 percent of them and that the space organization is prepared to deal with any that should pose a threat.

“You have to get an object about 30 meters in size or larger, about a third the size of a football field, or larger, before it can actually cause ground damage,” Yeomans said.

But should an object that big hit the Earth, even a skeptic like Yeomans describes the scenario as a “hellish environment” that would almost certainly wipe out humanity.

Such an impact would “shut out much of the sunlight and kill the plants, of course. You’ve got acid rain, you’ve got re-entering fiery ejecta,” Yeomans said. “You’ve got a pretty hellish environment.”

Based on the odds alone, it’s somewhat remarkable that a giant asteroid hasn’t wiped us out already.

Back in 1908, an asteroid estimated to be about 60 meters in diameter exploded over Siberia. The blast, known as the Tunguska Event, is said to have knocked down 80 million trees across more than 2,000 miles. The blast was 1,000 times more powerful than the atomic bomb dropped on Hiroshima in World War II. Thankfully, the impact occurred in a very remote area. Otherwise, it’s widely assumed that the damage to a populated region would have been catastrophic.

“Statistically, you’d expect an object of that size to hit the Earth about every million years or so. The last big one, of course, was 65 million years ago, about six miles diameter. It took out the dinosaurs,” Yeomans said.

Which means we’re long overdue for another giant asteroid impact.

NASA’s surprisingly simple solution to saving us from a giant asteroid

So, for the sake of argument, let’s say Yeomans and his colleagues at NASA do eventually spot a giant asteroid headed for Earth. What exactly could they do to stop it?

As he explains in his book “Near Earth Objects: Finding Them Before They Find Us,” the U.S. government tasked MIT students with this very scenario in 1965. Their solution? Launch a nuclear missile into space and blow up the asteroid.

Crazy as it may sound, Yeomans says that’s still one of the leading scenarios. But not before NASA tried some less explosive approaches first.

“The easiest approach is what I call KISS: Keep it simple stupid,” he said.

Basically, NASA would launch a spaceship that would intentionally crash directly into the asteroid, sending the deadly rock off course.

“You just sent a spacecraft up, run into it, slow [the asteroid] down just a few millimeters per second. So in 10 or 20 years when it was predicted to hit the Earth, it would miss by a wide margin,” Yeomans explained.

And then there’s the nuclear option.

“If you don’t have 10 or 20 years, you might want to send up a nuclear explosive device that would be set off either just off the surface, or you might try to bury that explosive device in the object in order to disrupt it completely,” he said.

So there you have it. Nearly every one of us gets up each morning and heads to work. But only one man is working every day to save the planet from asteroids.

And while Yeomans comes across as a humble, down to earth guy, he didn’t hesitate when we asked who would play him in a movie.

“That would have to be Harrison Ford, of course,” he said.


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