By
Jeremy Duda
Arizona Daily Wildcat
UA astronomer is part of the research group that found 24 new objects in Kuiper Belt
Astronomers have long thought that our solar system ends beyond Pluto, but three astronomers have now found evidence that there may be an "edge" to the solar system past the planet's orbit.
Renu Malhotra, a University of Arizona astronomy professor, and R. Lynne Allen and Gary Bernstein, both of the University of Michigan, revealed their findings at the Division of Planetary Sciences in Pasadena, Calif. Tuesday.
In 1992, two University of Hawaii astronomers, David Jewett and Jane Luu, discovered the Kuiper Belt, a group of objects orbiting beyond Neptune. The existence of this belt had long been theorized by astronomers, but this was the first proof of its existence. This led to the discovery of more than 300 belt objects.
Malhotra, Bernstein and Allen searched six patches of sky, each about the size of the Earth's moon, using a Charged Coupled Device camera at the Cerro Tololo Inter-American Observatory in the Chilean Andes Mountains. A CCD camera is a light-detecting device, and is the same kind of technology used in most hand-held video recorders, although on a much larger scale.
What they saw was 24 new Kuiper Belt objects, some of which are more than 100 miles wide. These objects are about 65 astronomical units from the earth. An AU is the distance between the Earth and the sun, which is about 100 million miles, said Malhotra. Neptune is about 30 AU from Earth, and Pluto ranges between 30 to 50, depending on where it is in its orbit. Previously, the furthest Kuiper Belt object was found about 55 AU from Earth.
Although no objects have been detected outside of the solar system, these new findings hint that there may be more out there, since the furthest one was found just inside Pluto's orbit.
"These objects out there are kind of fossils left over from the creation of the solar system," said Bernstein.
It has been hypothesized that these objects were formed inside the orbit of Pluto, but were pushed outside by encounters with planets, most likely Neptune. Some of the belt objects, as well as comets, are on trajectories that will take them outside the currently accepted edge of the solar system,
These objects are between 30 to 50 Kelvins in temperature, which is about 400 degrees Fahrenheit below zero. Their makeup is rock and ice, although the exact composition is unknown.
"Nobody's been there, so we don't have any information on the chemical composition," Malhotra said.
The study conducted by the three astronomers was funded by grants from NASA and the National Science Foundation. Many astronomers across the globe are currently conducting their own surveys on the Kuiper Belt.
