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Centaur's Bright Surface Spot Could be Crater of Fresh Ice

The unexpectedly varied surface of a wayward piece of space debris has given astronomers new insights into the characteristics and behavior of a ghostly population of faintly observed comet-like bodies that lie just beyond Pluto's orbit. While observing an object called 8405 Asbolus, a 48-mile-wide (80-kilometer-wide) chunk of ice and dust that lies between Saturn and Uranus, astronomers using the Hubble telescope were surprised to find that one side of the object looks like it has a fresh crater less than 10 million years old, exposing underlying ice that is apparently unlike any yet seen. This shows that these mysterious objects, called Centaurs, do not have a simple homogenous surface. Hubble didn't directly see the crater - the object is too small and far away - but a measure of its surface composition with its near-infrared camera shows a complex chemistry.

Research Credit: NASA, Donald W. McCarthy (University of Arizona), Susan D. Kern (University of Arizona)

Illustration Credit: Greg Bacon (STScI/AVL)