Interesting news on Planetoid... is that what Pluto is?

Frigid 'planetoid' found in solar system Sedna is so far out the sun is only a pale pinpoint of light
By JOHN NOBLE WILFORD THE NEW YORK TIMES

Far beyond Pluto, out where the sun is only a pinpoint of pale light, a frozen world has been found on the dark fringes of the solar system. Astronomers say it is by far the most distant object known to orbit the sun and the largest one to be detected since the discovery of Pluto in 1930.

With one discovery, it seems, the solar system has gotten much bigger, glimpses of its outer reaches bringing a sense of reality to what had been a remote frontier of hypothesis. And perhaps it has gotten stranger, too.

"There's absolutely nothing else like it known in the solar system," Dr. Michael Brown, an astronomer at the California Institute of Technology who led the discovery team, said yesterday of the world about 8 billion miles from Earth. (Sedna is so far out that from its distance the sun could be completely blocked out with the head of a pin, he said.)

He added, "Our prediction is that there will be many, many more of these objects discovered in the next five years, and some of them will probably be more massive."

That prediction is part of the reason researchers are calling the object -- 800 to 1,100 miles in diameter, or about three-quarters the size of Pluto -- a planetoid. A planet must be more massive than any other object in a similar location, said Brown, adding that he doubts Pluto should have the label of a planet.

The researchers, whose observations were supported by NASA, said the object is extremely frigid (minus 400 degrees Fahrenheit) and peculiarly red, probably more so than any other body in the solar system except Mars. They are not sure why, and also have few ideas of its composition. It could be a mix of rock and ice.

Brown's group has proposed naming the object Sedna, after an Inuit goddess. For now, it is designated as 2003 VB12. The first sighting was made in November at Palomar Observatory, operated by Caltech.

The team also have indirect evidence a tiny moon may trail Sedna.

This report includes information from The Associated Press and Bloomberg News.