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Image courtesy NASA/JPL-Caltech/R. Hurt (SSC-Caltech)
New planetoid named Sedna discovered
News story originally written on March 17, 2004
Astronomers have discovered a new planetoid at the far edge of our Solar System.
The new object, named Sedna, is probably almost as big as the smallest planet,
Pluto.
Sedna is very, very far away. It is more than twice as far from the Sun as
Pluto, and about 90 times as far from the Sun as Earth. Sedna is probably a
huge ball of ice. The ice is reddish in color. There are probably chemicals
in the ice that make it red.
Sedna orbits the Sun once every 10,500 years. Its orbit takes it out to about
900 times as far from the Sun as the Earth. Scientists aren't quite sure where
Sedna fits in with the rest of the Solar System. It is too far out to be part
of the Kuiper Belt, and too close in to be part of the Oort
Cloud.
Since Sedna is very cold because it is so far from the Sun, the astronomers
who discovered it decided to give it a name from a myth from people who live
near the North Pole. Sedna is the name of the sea
goddess in Inuit mythology.
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