Meet 2007 OR10: "the largest unnamed world in our solar system," according to NASA. At 955 miles in diameter, the dwarf planet is about two-thirds the size of Pluto, and is believed to have both water ice and methane on its surface.
The still-unnamed dwarf planet has an elliptical orbit that brings it about as close to the sun as Neptune, but with an orbital period of 548 years it takes over twice as long as Pluto to make it all the way around. A day on 2007 OR10 lasts is also extremely slow at about 45 terrestrial hours, and at the moment the dwarf planet is actually more than twice as far away from the sun as Pluto. That awkward distance made it a little difficult to calculate exactly how large and bright the object was until recently, when researchers at NASA Ames could combine data from the Herschel Space Observatory with visuals from the Kepler space telescope's K2 mission to accurately determine its size.
And now all it needs is a name. The little floater in the Kuiper Belt was originally nicknamed "Snow White" when astronomer Mike Brown's team at California Institute of Technology discovered it in 2007. At the time, it was presumed to be a bright, white object, but it turns out that 2007 OR10 is actually more deeply red, thanks to the methane frost on the surface. Although Brown's team has yet to propose a name, according to him anyone will be able to suggest a designation for it in 2017. Please, just don't call it Dwarfy McDwarfface.