New solar system member is tail-less comet called 2006 SQ372

William Atkins
Friday, 22 August 2008 22:29

Science - Space

Science News states, “Even at its farthest point from the sun, 2006 SQ372 is only a tenth as far as the main part of the proposed Oort Cloud. Simulations by Kaib suggest that this distance is far enough for the body to have been a resident of the inner part of the Oort Cloud.”

It adds, “It turns out, he notes, that only comets from the outer part of the Oort Cloud can quickly “hop” over the orbits of Jupiter and Saturn and make it near Earth. Therefore, the long-period comets that have so far been observed can only reveal the structure of the outer portion of the Oort Cloud.”

Further, “Theoretical models of the formation of the Oort Cloud predict that it should also host a massive inner part, but comets from this region never make it near Earth. To see the long-period comets from the inner region of the Oort Cloud requires observing comets whose orbits always stay well outside Saturn's orbit — like 2006 SQ372.”

And, "The gravity of a passing star could have flung the object out of the inner Oort Cloud and toward the inner part of the solar system. Other icy refugees from the cloud come much closer to the sun’s warming rays, suddenly venting pockets of ice and dust and flaunting the signature dusty tails of comets.”

“A much larger, Pluto-sized object called Sedna, codiscovered by Mike Brown of the California Institute of Technology in Pasadena in 2003, might also be a remote refugee from the inner Oort Cloud, Becker and Kaib suggest. Sedna doesn’t venture nearly as far out as 2006 SQ372 does, but it also doesn’t come as close to the sun, likely preserving more of the materials it acquired from the solar system’s outer reaches.”

On the other hand, “Brown says he would have thought that 2006 SQ372 is an escapee from a less-remote reservoir of frozen bodies, called the Kuiper Belt, which lies just beyond Pluto. 2006 SQ372 has a relatively short lifetime of about 180 million years, due to its gravitational interactions with Neptune and Uranus, while aloof Sedna has a stable orbit “and has been there for a long time,” notes Brown. The relatively unstable orbit of 2006 SQ372 means “it’s more or less impossible to predict where it was last time around,” he notes, but a large population of similar though less extreme objects has been identified as refugees from the belt.”

Additional information on the comet 2006 SQ372 and the Sloan Digital Sky Survey is found at: SDSS' “See you again in 22,000 years: Astronomers find an unusual new denizen of the Solar System”

ScienceDaily.com also reports on the new member of the solar system at: “Astronomers Find Unusual New Denizen Of The Solar System.”