Super-Clean Space Rock Puzzles Astronomers

More used to seeing rocks covered in grime after billions of years of floating around space, a team of astronomers at MIT are scratching their heads over a surprisingly pristine rock in Kuiper Belt, near Neptune.

After first spotting the rock several years ago, MIT astronomer James Elliot finally found out the true nature of the 89-miles-wide KBO 55636 rock using "stellar occultation," discovering it was extremely hygienic in comparison to every other object he'd seen out there. Stellar occultation is when the rock obscures the light of a star once it passes in front.

Elliot said that the reflectivity is "very high, almost 90 per cent...that's consistent with it having a very highly reflective surface like water ice." Has an alien life-form taken to the rock with a large toothbrush and some bleach? [BBC via Discover via Ebert]