Eris (dwarf planet)

Eris: A Big Dwarf Planet

Eris is a very big object in space. It is one of the largest dwarf planets in our Solar System. Eris is special because it is very far away from the Sun. It is what we call a trans-Neptunian object, which means it orbits the Sun beyond the planet Neptune.

Eris was discovered in January 2005 by a team from the Palomar Observatory. They were looking for large objects in the outer part of our solar system. Eris is almost as big as Pluto but a little heavier. It has one moon named Dysnomia.

Because Eris looked bigger than Pluto when it was first found, some people called it the tenth planet. But in 2006, scientists made new rules about what a planet is. Eris did not meet all the rules, so it is called a dwarf planet, just like Pluto. This helped us learn more about our solar system.

Eris is very far from the Sun. In February 2016, it was about 96.3 times farther from the Sun than Earth is. It takes Eris about 558 years to go around the Sun once. Its path around the Sun is tilted, which makes it hard to see from Earth.

Eris is made of dense materials, mostly rock. Some scientists think it might have a hidden layer of liquid water deep inside. Its surface is covered with ice, like methane and nitrogen ice. Because Eris is so far from the Sun, its temperature changes a lot, and sometimes its ices can turn into a thin atmosphere.

Eris spins slowly, taking about 15.78 Earth days for one full spin. It has a moon named Dysnomia, which spins in sync with Eris, making them a special pair, just like Pluto and its moon Charon.