Oct. 7 ? A newfound frozen world beyond the recognized nine planets of Earth?s solar system is the largest object discovered since Pluto was spotted in 1930. Its discovery raises the prospects that yet another object as big or perhaps larger than Pluto might lurk out there.
THE ROCK is about half Pluto?s size. It orbits the sun every 288 years, mostly beyond Pluto?s orbit.
At 4 billion miles (6.5 billion kilometers) from the sun, it is the most distant thing in the solar system photographed by an optical telescope. Its discovery will expand knowledge of the faraway sea of icy rocks in which it resides, astronomers said Monday.
The object has a provisional name of 2002 LM60. However, astronomers involved in the discovery at Caltech University in Southern California have dubbed it Quaoar (KWAH-o-ar), after the creation force of the Tongva tribe of the Los Angeles basin. Quaoar, as an official name, will have to await approval from the International Astronomical Union.
RECORD BREAKER
Fewer than 400 objects have been identified in a region of our solar system known as the Kuiper Belt, which extends beyond Pluto and at least one-fifth the way to the nearest star. Astronomers expect the belt to be laden with frozen rocks, perhaps billions of them the size of a city and hundreds of thousands as large as Massachusetts. None had been photographed before.
One big Kuiper Belt object, or KBO ? called Varuna ? was found two years ago and is about 40 percent as big as Pluto. Varuna was the record-holder for size in the far-out belt until now.
Quaoar?s co-discoverer, Caltech postdoctoral researcher Chad Trujillo, told Space.com last week he?s ?quite confident? Quaoar is larger than Varuna.
Quaoar was first detected in images taken June 4 with the Palomar Observatory?s 48-inch (1.2-meter) Oschin Telescope.
Trujillo and Caltech associate professor Mike Brown then used the Hubble Space Telescope?s new Advanced Camera for Surveys in July and August to make visual observations, determining Quaoar?s diameter to be roughly 780 miles (1,250 kilometers). Superimposed on America, it would blot out several Midwestern states.
A technique involving the detection of thermal radiation sets the diameter higher but is not considered as reliable. Varuna?s size was estimated by the thermal technique to be 560 miles (900 kilometers).
Quaoar also appears to be larger than Pluto?s moon, Charon, which is 745 miles (1,200 kilometers) in diameter.
IMPROVING PICTURE
Harold Levison, a Southwest Research Institute scientist who was not involved in the discovery, said it was important though not surprising.
?Its importance lies in the fact that we will be able to actually study the object in detail,? Levison said. ?Other KBOs are just too faint to study. It has been quite frustrating.? He added that the Kuiper Belt and its presumed pristine contents ?will tell us how the solar system formed.?
Another Kuiper Belt object, called Ixion and found last year, has been estimated to be 745 miles wide (1,200 kilometers) ? nearly the same size as Quaoar. But that calculation was based on an estimate for how much sunlight Ixion might reflect, a figure called albedo. Researchers used a 4 percent albedo, once considered the standard for Kuiper Belt objects. The number is based on what scientists know about asteroids and comets they?ve actually seen.
Quaoar?s albedo has been measured, not estimated, and it is 12 percent. Varuna?s is 7 percent, and the only other measured KBO albedo is for an object that reflects 10 percent of sunlight.
?The standard assumption of 4 percent albedo, where the Ixion estimate comes from, is much too dark,? Trujillo said. ?Assuming a mean albedo of 10 percent, Ixion is likely to be 760 kilometers (470 miles) in diameter.?
All this means that astronomers are getting a better handle on what?s out there and what the objects look like on their surfaces, which will eventually lead to a better understanding of what the rocks are composed of.
?The main practical importance is that these bigger, brighter objects are easier to study,? said David Jewitt, a University of Hawaii expert on KBOs. ?We can obtain physical data that are impossible on the fainter KBOs.?
the rest.....
http://www.msnbc.com/news/818195.asp#BODY or http://www.space.com/scienceastronomy/quaoar_discovery_021007.html
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But...if you've made your peace, then the devils are really angels
Freeing you from the earth.
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