From Earth we have looked deep into the universe, embarking on a journey of discovery that has revealed the cosmos to be richer than we could ever imagine. But what happens when we reverse the process, when we look back on Earth from the heavens? We see a familiar planet from a new perspective. With the satellite's all-seeing eye we can uncover cities swallowed by shifting sands or dense jungle; we can gaze into the eye of the hurricane or the maw of the volcano; we can watch forests disappear and ice sheets melt.