August 19, 2008

Minor Planet Leads To New Knowledge About Comets

According to researchers, a newly discovered "minor planet" may help explain how comets are created.

The new object, dubbed 2006 SQ372, is starting the outward portion of its elongated 22,500 year orbit, leaving it nearly 150 billion miles from the Sun at its farthest point.

On Monday, researchers said the icy object was over 2 billion miles from Earth, slightly closer than the planet Neptune.  The researchers' findings will be published in the Astrophysical Journal.

According to University of Washington astronomer Andrew Becker, the object's orbit is four times longer than it is wide, and is similar to Sedna, a Pluto-like dwarf planet discovered in 2003.  The object is also nearly 60 miles in diameter.

"It's basically a comet, but it never gets close enough to the Sun to develop a long, bright tail of evaporated gas and dust," said Becker, who also lead the team of researchers.

Nathan Kaib, a University of Washington graduate student, believes 2006 SQ372 "could have formed, like Pluto, in the belt of icy debris beyond Neptune, then been kicked a large distance by a gravitational encounter with Neptune or Uranus."

Although Kaib believes it is more likely that the object came from the Oort Cloud, a reservoir of icy, astroid-like objects that orbit the Sun at a distance several trillion miles away.

"One of our goals is to understand the origin of comets, which are among the most spectacular celestial events. But the deeper goal is to look back into the early history of our solar system and piece together what was happening when the planets formed," Kaib said.


Image Caption: A "minor planet" with an elongated orbit around the Sun. (Ohio State University)


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