"" (also written "Astronomical naming conventionsMinor_planets(66391) 1999 KW4") is an Aten asteroidAten and Mercury-crosser asteroid discovered by LINEAR in 1999.
has a asteroid moonmoon orbiting it. The moon, designated "S/2001 (66391) 1" or '1999 KW4 Beta' is ~360 m in diameter, and orbits 'Alpha' in 0.758 d (16 hours) at a distance of 2.6 km. The presence of a companion was suggested by photometric observations made June 19-27, 2000 by Petr Pravec and Lenka Šarounová at Observatoř Ondřejov (Ondřejov Observatory) and was confirmed by radar observations from Arecibo Observatory from May 21-23, 2001 by Lance A. M. Benner, Steven J. Ostro, Jon D. Giorgini, Raymond F. Jurgens, Jean-Luc Margot and Michael C. Nolan, announced on May 23, 2001.
The shapes of the two bodies and their dynamics are complex.NASA Jet Propulsion Laboratory , retrieved May 3, 2007 Among other bizarre properties, the equatorial regions of Alpha are very close to breakup: raising a particle a meter above the surface would put it into orbit around the object.References
Johnston, Wm. Robert, ed. January 7, 2007, retrieved May 3, 2007
Margot, Jean-Luc, November1999, retrieved May 3, 2007(66392) 1999 KF10
en.wikipedia.org
to main page 
top of page