Printed on: February 08, 2013

150-foot asteroid to 'buzz' Earth


CAPE CANAVERAL, Fla. (AP) -- A 150-foot-wide asteroid will come remarkably close to Earth next week, even closer than high-flying communication and weather satellites. It will be the nearest known flyby for an object of this size.

But don't worry. Scientists promise the megarock will be at least 17,100 miles away when it zips past Feb. 15.

"No Earth impact is possible," said Donald Yeomans, manager of NASA's Near-Earth Object program at Jet Propulsion Laboratory in Pasadena, Calif.

Even the chance of an asteroid-satellite run-in is extremely remote, Yeomans and other scientists noted. A few hundred satellites orbit at 22,300 miles, higher than the asteroid's path, although operators are being warned about the incoming object for tracking purposes.

"No one has raised a red flag, nor will they," Yeomans told reporters. "I certainly don't anticipate any problems whatsoever."

Impossible to see with the naked eye, the asteroid is considered small as these things go. By contrast, the one that took out the dinosaurs 65 million years ago was 6 miles wide.

Yet Asteroid 2012 DA14, as it's known for its discovery date, still could pack a wallop.

If it impacted Earth -- which it won't, scientists were quick to add Thursday -- it would release the energy equivalent of 2.4 million tons of TNT and wipe out 750 square miles. That's what happened in Siberia in 1908, when forest land around the Tunguska River was flattened by a slightly smaller asteroid that exploded about five miles above ground.

The likelihood of something this size striking Earth is once in every 1,200 years. A close, harmless encounter like this is thought to occur every 40 years.

The bulk of the solar system's asteroids are located between the orbits of Mars and Jupiter, and remain stable there for billions of years. Some occasionally pop out, though, into Earth's neighborhood.