In 2004 it was revealed in the media that a new planet had been detected in our solar system, making ten planets in total. (What became of 2000 WR106?)
Unveiled on the 15th March 2004, newspaper reports explained Sedna, named after an Inuit godess, is a deep-frozen world, more than eight billion miles from the sun. Between 800-1,100 miles in diameter, NASA described it as "the most distant object ever detected orbiting the sun."
It is estimated that the temperature of Sedna is always below -200C; and it takes 10,500 years to orbit the sun in a possible orbit of 84 billion miles diameter, 900 times that of the distance between Earth and the sun.
Mike Brown, of the California Institute of Technology and one of the astronomers who found Sedna in November 2003, said "The sun appears so small from that distance you could block it out with the head of a pin."
But is it really a planet?
Senior astronomer Doctor Robin Catchpole, of the Royal Observatory, Greenwich, said "Sedna has been located in an area of space known as the Kuiper Belt, which contains hundreds of objects orbiting the sun." Some astronomers claim it is but a very large asteroid, the same as what some believe about Pluto." It seems the orbit is all important, if it it circular, then it adds to the chance of it being a planet.
