AAS DPS 2008: Icy iconoclast
Could a renegade, retrograde ice ball signal a new population of distant bodies in the solar system? Brett Gladman of the University of British Columbia in Vancouver was on hand at a press briefing here to describe his discovery earlier this year of a 50-kilometre chunk of ice that doesn't fit with known populations. It was discovered with a Hawaiian telescope, as a part of a Canadian-French survey of objects beyond the orbit of Neptune. The body, called 2008 KV42, has an orbit that is past perpendicular (104 degrees) to the ecliptic plane of the solar system, and its motion is opposite that of the planets. “That must be due to where it comes from,” says Gladman. The strange orbit has Gladman speculating about a third source of bodies besides the Kuiper Belt and the Oort Cloud. Compositionally, the ice ball fits well with the Kuiper Belt, the ring of Pluto-like ice and rock balls past Neptune, but it's orbit doesn't gibe at all. And while comets from the more distant Oort Cloud have retrograde, highly inclined orbits, this isn't a comet. The team has nicknamed the object Drac, after Dracula, for its ability to walk on walls. Ron Cowen over at Science News has more here.
