Radar Observations of Near-Earth Asteroid 2008 EV5

Arecibo delay-Doppler images of EV5 from 2008 Dec 23-27.
Resolution is 0.05 µs x 0.0625 Hz (7.5 m x 7.9 mm s-1).
These images are sums of six Arecibo runs each and each covers ~7º of rotation phase.
The asteroid appears to rotate counter-clockwise.
EV5 rotates retrograde and its overall shape is a 400 ± 50 m oblate spheroid.
The most prominent surface feature is a ridge parallel to the asteroid's equator that is broken by a concavity 150 m in diameter.
Otherwise the asteroid's surface is notably smooth on decameter scales.
EV5's radar and optical albedos are consistent with either rocky or stony-iron composition.
The equatorial ridge is similar to structure seen on the rubble-pile near-Earth asteroid (66391) 1999 KW4 and is consistent with YORP spin-up reconfiguring the asteroid in the past.
We interpret the concavity as an impact crater.
Shaking during the impact and later regolith redistribution may have erased smaller features, explaining the general lack of decameter-scale surface structure.

Reference article & source images: http://arxiv.org/ftp/arxiv/papers/1101/1101.3794.pdf

Image processing & video editing: Marco De Marco (madema6)

Marco De Marco related pages: http://www.facebook.com/pages/Amsterdam-Astronomical-News/141897832520661 http://www.youtube.com/user/madema6/

Category:

Science & Technology

Tags:

• 2008 EV5
• neo
• asteroid
• radar
• observations
• arecibo
• nasa
• madema6