Corkscrew Asteroid



A tiny asteroid looping around Earth for the past seven years is about to
leave the neighborhood.

June 9, 2006: News flash: Earth has a "second moon." Asteroid 2003 YN107
is looping around our planet once a year. Measuring only 20 meters across, the
asteroid is too small to see with the unaided eye-but it is there.

This news, believe it or not, is seven years old.

"2003 YN107 arrived in 1999," says Paul Chodas of NASA's Near Earth Object
Program at JPL, "and it's been corkscrewing around Earth ever since." Because
the asteroid is so small and poses no threat, it has attracted little public
attention. But Chodas and other experts have been monitoring it. "It's a very
curious object," he says.

Right: The typical corkscrew path of an Earth Coorbital Asteroid. [More]

Most near-Earth asteroids, when they approach Earth, simply fly by. They
come and they go, occasionally making news around the date of closest approach.
2003 YN107 is different: It came and it stayed.

"We believe 2003 YN107 is one of a whole population of near-Earth
asteroids that don't just fly by Earth. They pause and corkscrew in our vicinity
for years before moving along."




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