Wednesday, October 26, 2011
Faraway dwarf planet Eris is Pluto's twin
Astronomers have accurately measured the diameter of the faraway dwarf planet Eris for the first time by catching it as it passed in front of a faint star. This event was seen at the end of 2010 by telescopes in Chile, including the TRAPPIST telescope at ESO's La Silla Observatory. The observations show that Eris is an almost perfect twin of Pluto in size. Eris seems to have a very reflective surface, suggesting that it is covered in ice, probably a frozen atmosphere, (Nature, Ars Technica, and Physics World). The dwarf planet Eris and its moon Dysmonia are depicted in this 30-second animation.