In the wild unknown , out beyond the orbit of Neptune, astronomers have found a tiny world that defies our understanding of skies. This baffling object measures around 500 kilometers (310 miles) across, too small for its weak gravity to retain an atmosphere for long – yet an atmosphere it has. It's thin and tenuous, to be sure, but a world as small as (612533) 2002 XV 93 shouldn't have an atmosphere at all. It may not sound like much, but this relatively minuscule chunk of ice and rock in the