US: A newly discovered dark and frigid world, a bit smaller than Pluto and three times farther away, has emerged as the most distant object in the solar system, astronomers said yesterday.
The new "planetoid," named Sedna after an Inuit goddess who created the sea creatures of the Arctic, is by far the coldest and most distant object known to orbit the sun, a team of researchers announced.
At more than 13 billion km from the sun, the temperature on Sedna never gets above minus 240 Celsius.
"The sun appears so small from that distance that you could completely block it out with the head of a pin," said Mike Brown, an astronomer at California Institute of Technology, who led the research team.
First detected on November 14th with the Samuel Oschin Telescope near San Diego, California, Sedna was observed within days on telescopes from Chile to Spain, Arizona and Hawaii.
NASA's orbiting Spitzer Space Telescope found that Sedna probably has about three-fourths the diameter of Pluto, which would make it the biggest object found in the solar system since Pluto's discovery in 1930.