As Dawn slowly approaches Ceres, this dwarf planet's inexplicable white spot is increasingly coming into focus. Thanks to xkcd's Randall Munroe, we may finally have the answer.
This striking image from the Cassini orbiter shows Saturn's northern hemisphere engulfed in a massive storm that has raged for well over a year. This storm was bigger than Earth when it began, and it's since gotten even more massive.
Just as the Northeast recovers from its major blizzard, Saturn has to upstage the whole thing with the reemergence of the Great White Spot, a massive storm system in the planet's southern hemisphere that can be several thousand kilometers across.