[X] My Assistant

[dilo]

Last Science issue reports a couple of articles about binary near-Earth asteroid 66391 (1999 KW4).
Ostro et al. (see the cover) used radar to map the binary Earth-approaching asteroid (66391) 1999 KW4 and deduce its physical properties. Alpha, the main component (1.5Km size) is an unconsolidated aggregate and spins on its axis every 2.8 hours. The smaller companion, Beta, is elongated and denser than Alpha.
Scheeres et al. model the coupled orbital and rotational dynamics of the system. Alpha is spinning at a rate near its break-up speed, and the authors suggest that the system may have been put into its excited state by a close pass with the Sun or Earth. The binary asteroid may have ultimately originated from the disruption of a rubble-pile precursor.
Last article contains also amazing long video as supporting material:
http://www.sciencemag.org/content/vol0/iss...1/1133599s1.mov
(not sure if everybody can access)

[Decepticon]

I thought this was neat! Asteroid models!

[karolp]

And here you can hear Steve Ostro himself talking about the asteroid and about slashing funds and closing the Arecibo facility in a few years without any perspectives on a replacement - which would mean an end to near Earth asteroid research and making Earthlings as helpless as dinosaurs again:

http://www.planetary.org/audio/avfiles/pr20070101_32kb.mp3

http://www.planetary.org/audio/avfiles/pr20061225_32kb.mp3