spacetoday.net: Hubble observes asteroid breaking apart

Posted: Fri, Mar 7, 2014, 7:12 AM ET (1212 GMT)
P/2013 R3 breakup (NASA/ESA/D. Jewitt)

Images from the Hubble Space Telescope reveal an asteroid breaking apart into as many as ten pieces, perhaps due to the subtle influence of the Sun. Hubble images of P/2013 R3, taken between October and January, show the object breaking up into several smaller pieces, the largest of which are up to 400 meters in diameter. The asteroid, discovered in September, was initially categorized as a comet given its fuzzy appearance in telescopes. Astronomers now believe the object is an asteroid that has fractures and is surrounded by a coma of dust from that breakup. Astronomers don't believe a collision caused the breakup, and have ruled out heating of ices in the interior as an alternative cause. Instead, astronomers think the most likely cause is that sunlight gradually sped up the rotation rate of the asteroid to the point where centrifugal forces caused the object to fly apart.