August 25, 2008
New Objects Discovered In Space
A new haul of objects closer to home have been found by astronomers looking through the data from the Sloan Digital Sky Survey.
A team led by Dr. Andrew Becker, of the University of Washington, has discovered almost 50 new asteroid-sized bodies in the outer regions of our Solar System by searching through a survey region known as Stripe 82.
The robotic Sloan telescope in New Mexico revisited this area of the southern sky every three days in a search of supernovae.
By comparing images taken on different nights, the Washington team was able to detect the asteroids as they moved across the sky.
"If you can find things that explode, you can also find things that move, but you need different tools to look for them," said team member Dr. Lynne Jones.
Two Neptunian Trojans were discovered at the Kuiper Belt, a large band of icy bodies stretching beyond the orbit of Neptune.
"Jupiter has plenty of trojans, and we knew that Neptune must have a similar population of objects. Surprisingly, not many had been found before this survey," said Dr. Becker.
An icy body that is currently roughly two billion miles away temporarily named 2006 SQ372 is the team's prize find. This asteroid, which is 30-60 miles across, is beginning its journey that will take it out to a distance of 150 billion miles from Earth.
According to Dr. Becker, it is not a normal asteroid.
"It's probably a mixture of ice and rock, rather like a comet although it never comes close enough to the Sun to develop a tail," said Dr Becker.
The orbit of the new object is also unusual. Sedna, which was discovered in 2003, might come from the same region of the Solar System.
Simulations carried out by a third member of the team, Nathan Kaib, show that 2006 SQ372 won't stay in its current orbit for long.
"Sedna is in a stable orbit, and has probably been there for billions of years, but in more than half of our simulations our new object got too close to either Uranus or Neptune within 180 million years," he explained.
Any kind of interaction with either of the asteroids large neighbors would send it spinning in a random direction, making its journey impossible to predict.
Sedna and 2006 SQ372 might represent the first two known objects to have come from the inner edge of the Oort cloud, a vast reservoir of cometary material believed to exist right on the edge of the Solar System.
Further study will confirm if this really is the new object's home. In the meantime, Dr. Becker will be trying to think of a permanent name.
"It will end up with the name of either a centaur, or a mythological name associated with the underworld or creation."
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