(opens in new tab) A never-before-seen ecosystem lurks in an underground river deep below the icy surface in Antarctica. Researchers recently brought this "hidden world" into the light, revealing a dark and jagged cavern filled with swarms of tiny, shrimplike creatures.

A mantle plume producing almost as much heat as Yellowstone supervolcano appears to be melting part of West Antarctica from beneath. Researchers at NASA have discovered a huge upwelling of hot rock under Marie Byrd Land, which lies between the Ross Ice Shelf and the Ross Sea, is creating vast lakes and rivers under the ice sheet.