Eris (dwarf planet)
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136199 Eris, known before as "2003 UB 313", is a dwarf planet and a trans-Neptunian object (also known as TNO) in the solar system. It is the largest dwarf planet known so far, and it is bigger than Pluto. It was discovered by Michael E. Brown, Chad Trujillo, and David Rabinowitz on January 5, 2005, when they had a close look at some old images of the outer solar system that were taken in 2003. Eris was firstly known as "Xena", named after the main character of the television series Xena: Warrior Princess. Eris has one companion moon called Dysnomia, also known before as "2003 UB 313", discovered on September 10, 2005. Dysnomia had a nickname called "Gabrielle", named after the character in the same television series as "Xena". It was then officially named Eris on September 13, 2006. Eris was named after one of the goddesses in Greek mythology. The moon, Dysnomia, was named after Eris' daughter in the Greek myths. Both Eris and Dysnomia could not be named Xena or Gabrielle because it was a rule that all objects orbiting outside Neptune's orbit had to be named after a creation mythology.
Many media reports argued that Eris is the tenth planet, along with many astronomers and scientists from NASA who supported that idea because it was bigger than Pluto. However, on August 2006, Eris has lowered in status to a dwarf planet, after people decided to re-define the term, "planet".
Today, scientists continue to find out more information about Eris and its moon Dysnomia, as well to look for more moons or any rings.
Eris is a scattered disk object, as it is found within the Kuiper belt region of the solar system, and it is beyond Pluto's orbit. It is also called a "pluton", because its size, orbit, and location is similar to Pluto.
Eris orbits around the Sun for 557 Earth years, and today it is located furthest away from the Sun. It has an elliptical orbit, meaning it is not circular in shape, and it is tilted at an angle of 44 degrees. Eris is 2400 kilometres in diameter, slightly bigger than Pluto.
[change] See also
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| The Sun · Mercury · Venus · Earth · Mars · Ceres · Jupiter · Saturn · Uranus · Neptune · Pluto · Eris |
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Planets · Dwarf planets · Moons: Terrestrial · Martian · Jovian · Saturnian · Uranian · Neptunian · Plutonian · Eridian
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Small bodies: Meteoroids · Asteroids/Asteroid moons (Asteroid belt) · Centaurs · TNOs (Kuiper belt/Scattered disc) · Comets (Oort cloud)
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| See also: List of solar system objects |
