What Is Eris Made Of?

Eris, a dwarf planet discovered in 2005, is named for the Greek goddess of warfare and strife.

Eris, a dwarf planet recently discovered by a research team led by Michael Brown from California Institute of Technology, is similar to Pluto in size and mass. Armed with that information, scientists made the informed guess that Eris is like Pluto in its composition of rock and ice. Studies of the dwarf planet's characteristics continue.

Surface

By studying the sunlight reflected off the surface of Eris, scientists think that Eris has a surface that is similar to the planet Pluto. The sunlight indicates a surface covered with a solid frozen methane gas or natural gas. Methane is present on Earth in gaseous forms. Because of the extremely low temperatures, the methane would be frozen solid on Eris.

Interior

Scientists believe the interior of Eris is probably a rock and ice mixture, similar to Pluto's interior. Until scientists can learn more about the actual density of the planet, they can only speculate about the interior's composition.

Atmosphere

Eris orbits around the sun every 280 years. The planet is now as far from the sun as it gets in its orbit. Scientists believe that at this time the atmosphere, likely consisting of methane and nitrogen, is frozen solid to the surface of the planet. Over the course of the 280-year orbit, as the planet gets closer to the sun, the atmosphere evaporates.

References

• California Institute of Technology Division of Geology and Planetary Sciences: The Discovery of Eris, the Largest Known Dwarf Planet
• Space.com: Dwarf Planet Outweighs Pluto

Resources

• Caltech: Geological & Planetary Sciences: The discovery of Eris, the largest known dwarf planet