At least 10 planets orbit the sun, Nasa's latest discovery

Scientists in the United States were expected to announce today that they had found a new "planet" in our solar system, after spotting a 10th heavenly body orbiting the sun.

After sightings by the Hubble telescope and the Spitzer space telescope, Nasa has announced that it would present the "discovery of the most distant object ever detected orbiting the sun".

The find was made by Dr Michael Brown, associate professor of planetary astronomy at the California Institute of Technology, in Pasadena, who is working on a Nasa-funded project, the organisation said.

The object has been named Sedna, after the Inuit goddess of the ocean.

The body is believed to be about 1,250 miles across, but may even be larger than the furthest known planet, Pluto, which was discovered in 1930 and has a diameter of 1,406 miles, informs &to=http://www.guardian.co.uk' target=_blank>Guardian

Brown and his colleagues estimate the temperature on Sedna never rises above 400 degrees below zero Fahrenheit, making it the coldest known body in the solar system.

Sedna follows a highly elliptical path around the sun, a circuit that it takes 10,500 years to complete. Its orbit loops out as far as 84 billion miles from the sun, or 900 times the distance between the Earth and our star.

Brown and Chad Trujillo, of the Gemini Observatory in Hawaii, and David Rabinowitz, of Yale University, discovered Sedna on Nov. 14, 2003, using a 48-inch telescope at Caltech's Palomar Observatory east of San Diego.

Within days, other astronomers around the world trained their telescopes, including the recently launched Spitzer Space Telescope, on the object, report &to=http://www.foxnews.com' target=_blank>FoxNews