A planet-like body three times farther from Earth than Pluto, is the most distant object known so far in the solar system, a group of US astronomers reported Monday (Mar. 15).

"The object, called Sedna for the Inuit goddess of the ocean, is 13 billion kilometers away, in the farthest reaches of the solar system," NASA, the US space agency that funded the research, said in a statement.

It is estimated that Sedna is less than 1,700 kilometers in diameter. Nearly three-fourths the size of Pluto, it is likely thelargest object found in the solar system since Pluto was discovered in 1930.

According to the astronomers, Sedna is extremely far from the sun, in the coldest know region of our solar system, where temperatures never rise above minus 240 degrees Celsius.

The planet-like object is usually even colder, because it approaches the sun only briefly during its 10,500-year solar orbit.At its most distant, Sedna is 130 billion kilometers from the sun, which is 900 times Earth's solar distance.

Sedna will become closer and brighter over the next 72 years, before it begins its 10,500-year trip to the far reaches of the solar system, the astronomers predicted.

"The last time Sedna was this close to the sun, Earth was just coming out of the last ice age," said Mike Brown, associate professor of planetary astronomy at the California Institute of Technology and leader of the research team.

"The next time it comes back, the world might again be a completely different place," he said.

Editor: Donald