While we were in school, we learned that our Solar System is made up of nine planets, namely Mercury, Venus, Earth, Mars, Jupiter, Saturn, Neptune, and Pluto. However, we may have to unlearn this knowledge. In the year 2006, the International Astronomical Union began to use another method of classifying stellar objects. This classification believed that 3 types of stellar objects were present in the Solar System, namely planets, dwarf planets, and Solar System bodies.
Under this classification, Pluto was assigned as a dwarf planet and was no longer considered a planet. Although dwarf planets orbit the sun, they are not strong enough to overcome the forces and form a round shape. In addition, they are unable to clear the path of their orbit of objects that could be satellites of other planets. Today, there are 5 dwarf planets that we know of. They are Eris, Pluto, Haumea, Makemake and Ceres. Of all the known dwarf planets, the largest is Eris, while the smallest is Ceres.
Eris was first seen in 2003, but it was only confirmed in 2005, in January by an astronomer from the California Institute of Technology named Michael Brown. It is the most distant stellar object discovered in orbit around the Sun.
One of those discovered, Eris was first named 2003 UB313. She then earned the nickname Xena, and finally, in September 2006, the dwarf planet was officially named Eris by the International Astronomical Union.
The name of the dwarf planet was taken from Greek mythology. Eris was the goddess of war and conflict. She was responsible for bringing hatred, anger, and jealousy among the men, causing them to fight each other. The name was carefully selected as the discovery of this dwarf planet was plagued with controversy. The astronomical community was happy with the way Eris was classified. Therefore, she got an appropriate name.
Eris has a slightly larger diameter compared to Pluto at 2,400 kilometers. It is located about 97 AU from the Sun and takes about 577 years to complete one orbit around the Sun. The temperature on Eris ranges from -217 degrees Celsius to -243 degrees Celsius.
Scientists believe that the outer layer of Eris is made up of frozen methane that has managed to seep into the interior. Because not much radiation from the Sun reaches the dwarf planet, Eris’s surface is yellowish in color. Until now, scientists have been able to discover only one moon revolving around Eris and have named the moon Dysnomia, which in Greek mythology was the daughter of Eris. Dysnomia takes about 2 weeks to orbit Eris.
In order to see Eris, you need an extremely powerful telescope. You won’t be able to see this planet with a pair of binoculars or with the naked eye.