Hubble Witnesses Disintegration of Asteroid
Posted on March 6, 2014
NASA's Hubble Space Telescope captured the break-up of an asteroid into many smaller pieces. Astronomers say this has never been observed before in the asteroid belt. The crumbling asteroid is designated P/2013 R3. It was first noticed by the Catalina and Pan STARRS sky surveys on Sept. 15, 2013. The asteroid was examined again with the W. M. Keck Observatory on the summit of Mauna Kea, Hawaii. This observation revealed three bodies moving together in a large envelope of dust. Hubble was then used to observe the disintegrating asteroid as seen in the images above.
David Jewitt of the University of California at Los Angeles, who led the astronomical forensics investigation, says in the announcement, "This is a rock, and seeing it fall apart before our eyes is pretty amazing. The Keck Observatory showed us this thing was worth looking at with Hubble. With its superior resolution, space telescope observations soon showed there were really 10 embedded objects, each with comet-like dust tails. The four largest rocky fragments are up to 400 yards in diameter, about four times the length of a football field."
Astronomers say it is unlikely the asteroid broke apart from a collision with another asteroid. They have also ruled out the asteroid coming unglued due to the pressure of interior ices warming and vaporizing. The astronomers think the asteroid disintegrated due to a subtle effect of sunlight.
The astronomers say sunlight causes the rotation rate of the asteroid to gradually increase. Astronomers say in a statement, "Eventually, its component pieces -- like grapes on a stem -- succumb to centrifugal force and gently pull apart. The possibility of disruption in this manner has been discussed by scientists for several years, but never reliably observed."