Friday Flyby: How Scientists Track Near-Earth Asteroids

On Friday (Feb. 15), a space rock approximately the size of the White House will whiz past Earth, coming as close as 17,200 miles (27,700 kilometers) to the planet — a close call in astronomical terms. But how do scientists track an asteroid's path?

Telescopes and math. Observations of asteroids and other near-Earth objects are made optically; in the case of this week's flyby, researchers at Spain's La Sagra Observatory discovered the asteroid (called 2012 DA14), in February of last year. Once an astronomer identifies an object, its path can be tracked.

The flight paths of space objects are very predictable, said Mark Boslough, a physicist at Sandia National Laboratories in New Mexico who researches asteroid impacts.

"If you precisely know the location and the speed of something, well then, you can predict where it's going to be at any time in the future, as long as you don't go too far out," Boslough said.

more here: http://www.space.com/19770-scientist-track-near-earth-asteroid.html?cid=dlvr.it