Earth has acquired a "quasi-moon" - an asteroid that will encircle our planet for the next couple of years while it orbits the sun on a horseshoe-shaped path, according to a report to be published on Saturday in New Scientist.
The asteroid, 2003 YN17, "is probably a chunk of debris" from an impact between a larger space rock and the surface of the moon, the British weekly said.
2003 YN17's orbital plane is roughly the same as the earth's, but its unusual path, compounded by a corkscrew-like track, means that sometimes it is ahead of us and sometimes it is behind, inform dsc.discovery.com Discovery channel
"Since 1996, its path has taken it round the earth, making it a quasi-satellite. This phase will last until 2006," the report says.
The finders are a team led by Paul Chodas, an asteroid specialist at NASA's famed Jet Propulsion Laboratory in California.
Two other "quasi-moons" - temporary fellow-travellers that loop around the earth for while as they girdle the sun - have been spotted in recent years: Cluithne and asteroid 2002, report news24.com