Yarkovsky–O'Keefe–Radzievskii–Paddack effect or YORP
Hubble witnesses an asteroid mysteriously disintegrating
The NASA/ESA Hubble Space Telescope has photographed the never-before-seen break-up of an asteroid, which has fragmented into as many as ten smaller pieces.
Although fragile comet nuclei have been seen to fall apart as they approach the Sun, nothing like the breakup of this asteroid, P/2013 R3, has ever been observed before in the asteroid belt.
"This is a rock. Seeing it fall apart before our eyes is pretty amazing," said David Jewitt of UCLA, USA, who led the astronomical forensics investigation.
http://www.spacetelescope.org/news/heic1405
The Yarkovsky–O'Keefe–Radzievskii–Paddack effect, or YORP effect for short, is a second-order variation on the Yarkovsky effect that changes the rotation rate of a small body (such as an asteroid). The term was coined by David P. Rubincam in 2000.
In the 19th century, Ivan Yarkovsky realised that the infrared radiation escaping from a body warmed by the Sun carries off momentum as well as heat. Translated into modern physics, each photon escaping carries away a momentum p = E/c where E (= hν) is its energy and c is the speed of light.
Radzievskii applied the idea to rotation based on changes in albedo and Paddack and O'Keefe realised that shape was a much more effective means of altering a body's spin rate.
Paddack and Rhee suggested that the YORP effect may be the cause of rotational bursting and eventual elimination from the solar system of small asymmetric objects.
http://tinyurl.com/redirect.php?num=YORP-effect
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