Vlad the Impaler is one of history's most feared villains. Known for impaling his victims on spikes, this sadistic ruler was the inspiration behind Dracula. Now, experts believe a series of strange mounds may be the site of his burial. Hundreds of satellites orbit Earth and capture the world like it’s never been seen before, revealing phenomena that defy explanation. 'What On Earth' explores these unusual images as scientists attempt to explain mysteries seen from space.