Collisions are rare, but inevitably, they happen—it accounts
for craters on the Moon, and some of the features on the Earth.
(Image: Main-belt asteroid (493) Griseldis with temporary
tail. Credit: David Tholen, Scott Sheppard of Carnegie Institution, Chad
Trujillo of Gemini Observatory.)
And recently, a University of Hawai`i telescope helped spot
one out farther from the sun in our own solar system.
Out in the Asteroid Belt, between Mars and Jupiter, on March
17, astronomers using the 8-meter Subaru Telescope on Mauna Kea noticed that an
asteroid named Griseldis had suddenly grown a tail.
Several days later, the 6.5-meter Magellan telescope in
Chile showed the tail was still there, but smaller.
Images taken by the University of Hawai`i’s 2.2-meter
telescope on Mauna Kea showed that the tail did not exist back in 2010 or 2012,
and that it had disappeared by March 24. Magellan on April 18 and May 21 also
showed the tail was gone.
University of Hawai`i astronomer David Tholen reported the
results at a Nov. 12 session of the Division for Planetary Sciences of the
American Astronomical Society.
The sudden appearance and quick disappearance of a tail
suggests something crashed into the asteroid, caused a plume of dust, which
then dissipated, Tholen said.
“The observations are consistent with the occurrence of an
impact event on this asteroid,” the research group working on the project said.
The University of Hawai`i press release on the event
is here.
is here.
© Jan TenBruggencate 2015
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