2nd Moon Orbiting Earth Discovered

Arctic Fox writes "Astronomers at the Queen Mary & Westfield College in London have discovered a new moon. Named Cruithne, the 3 mile sized "moon" has a horseshoe shaped orbit that is 770 years in length." Heh. Lunar eclipses are just a bit rarer with this moon.

Comments

Old News, actually

[Captn Pepe]

Trojan asteroid 3753 Cruithne was actually shown to be orbiting the Earth in the June 12, 1997 issue of Nature. However, as its orbital motion is pretty complex, I don't doubt that it took this long to confirm the result. Simply put, 3753 Cruithne has the most complex horseshoe-type orbit ever observed. See this site for a more detailed analysis.

Of course, this technically shouldn't be termed a moon. This body shares an orbit with the Earth about the sun, and does not in any usual sense orbit the Earth. Instead, their orbits coincide so that Cruithne can occupy the same orbital region as the Earth over long periods of time without being ejected by a close approach.