Asteroid Deflection Research Center

The Iowa State University website, on May 22nd 2008, has news that they will be hosting an Asteroid Deflection Research Center on their campus for researchers from around the world to talk about different methods of deflecting asteroids. The article says,

Just 100 years ago, June 30, 1908, an asteroid or comet estimated at 100–200 feet in diameter exploded in the skies above Tunguska, Siberia. Known as the Tunguska Event, the explosion flattened trees and killed other vegetation over a 500,000-acre area. But if the explosion had occurred four hours later, it would have destroyed St. Petersburg or Moscow with an equivalent energy level of about 500 Hiroshima nuclear bombs.

Last November, NASA reported 900 known potentially hazardous objects (PHOs), most of which are asteroids. PHOs are defined as objects larger than 492 feet in diameter whose trajectories bring them to within about 4.6 million miles of the Earth’s orbit. NASA scientists estimate the total population of PHOs to be around 20,000. “However,” Wie said, “the asteroid we have to worry about is the asteroid that we don’t know.”

According to Tom Shih, professor and chair of aerospace engineering, “the potential for a major catastrophe created by an asteroid impacting Earth is very real. It is a matter of when, and humankind must be prepared for it."

Bad news indeed, but at the end of the article we have something a little more reassuring.

The chances of having to use deflection technologies on an asteroid in the near future are admittedly remote. Scientists estimate the frequency of an extinction-class (6 miles in diameter or larger) object striking Earth as once every 50–100 million years, and for a 200-foot or larger object as once every 100–500 years.

The estimate is for one every 100-500 years, but the last one was a 100 years ago, therefore the next one can happen at anytime. Is it time to panic?

The website is www.engineering.iastate.edu