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When Eris was first found, it was called Xena. Xena was the name of a warrior princess on a television show.

Eris is the largest known dwarf planet in our solar system. It is a little larger than Pluto. Eris is about 2400 kilometers wide.

Eris was first found by a team of astronomers at Palomar Observatory in California. Mike Brown and his team found Eris in 2003. It was not until 2005 that Eris was identified as another possible planet in our solar system. In 2006, astronomers decided that Eris should not be called a planet. They also decided that Pluto should no longer be called a planet. Both Eris and Pluto became known as dwarf planets. This is a special name created for objects in our solar system that don't meet all of the planet requirements.

Eris is the most distant member of our solar system known at this time. It is 3 times farther out than Pluto. One trip around the Sun takes 557 Earth years for Eris.

Observations of Eris have led scientists to believe it has frozen methane on its surface. Eris appears gray in color. Dysnomia is the only moon of Eris that we now know about.

Eris and Dysmonia

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A Question

As you are traveling out of our solar system, will you reach Pluto or Eris first?

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The Facts
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The Answer
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The StarChild site is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA/ GSFC.

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