Ammon News - On January,5 2005, the most massive and second-largest known dwarf planet in the Solar System, was discovered on this day in 2005 by a Palomar Observatory-based team led by Mike Brown.

The planet’s discovery, which led to the downgrading of Pluto, was verified later that year and in September 2006 it was named Eris, after the Greco-Roman goddess of strife and discord.

Eris is the ninth-most massive known object directly orbiting the Sun, and the sixteenth-most massive overall in the Solar System (including moons). It is also the largest object that has not been visited by a spacecraft.

Eris has been measured at 2,326 ± 12 kilometers (1,445 ± 7 mi) in diameter. Its mass is 0.27% that of the Earth and 127% that of dwarf planet Pluto, though Pluto is slightly larger by volume.