Earth’s ‘Second Moon’

Earth has a “second moon.” Asteroid 2003 YN107 is looping around our planet once a year.

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.

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.”

You can go here to check out a simulation of the orbit.