Eris

 

Discovered by: Michael E. Brown, Chad Trujillo, and David L. Rabinowitz

 

Discovery Announcement: January 5, 2005

 

Diameter: 1,490 miles

 

Distance from the Sun (current): 8.9 billion miles

 

Orbital Period: 557.8 years

 

Surface Temperature: -405 degrees Fahrenheit

 

Surface Composition: Methane ice

 

Moon: Dysnomia, 190 miles in diameter