Sedna

Sedna is a large trans-Neptunian object that was, as of 2012, about three times as far from the Sun as Neptune. •Spectroscopy has revealed that Sedna's surface composition is similar to that of some other trans-Neptunian objects, being largely a mixture of water, methane and nitrogen ices with tholins. Its surface is one of the reddest in the Solar System. It is probably a dwarf planet. Seedna is the coldest object in the Solar System at -240°C (400°F).