A New Moon for Earth?
AFP
The Asteroid "2003 YN17" To Orbit Earth
March 26, 2004 — 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.
Here is the article by discovery channel. There as also a small picture, ( but I may not post attachments?)