Post by Chicago Astronomer - Astro Joe on Jul 29, 2006 17:48:16 GMT -6
Cruithne: Also known as asteroid 3753, or 1986 TO, or "Earth's second moon".
The near-Earth asteroid 3753 Cruithne is now known to be a companion, and an unusual one, of the Earth. This asteroid shares the Earth's orbit, its motion "choreographed" in such a way as to remain stable and avoid colliding with our planet. This relationship was revealed in a paper by Paul Wiegert, Kim Innanen and Seppo Mikkola, and published in the British-based science journal Nature on June 12, 1997. A brief non-technical description of the motion of Cruithne is presented below. However, Cruithne's path is much more complicated than simple satellite motion; pondering the diagrams carefully should help clarify matters.
www.astro.uwo.ca/~wiegert/3753/3753.html
Here is a nice site with animated diagrams of Cruithne:
www.burtleburtle.net/bob/physics/cruithne.html
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Second Moon or not, it's still cool...
