In Antarctica, volcanoes leak hot, moist gases that melt their way through the ice and escape through natural vents called fumaroles. The escaping moisture instantly freezes in the cold air and is sculpted by wind into gnarled towers of ice. Below the surface, in hollowed caverns that can stretch for hundreds of feet, microbiologists search for microbes that could be analogous to alien life. This cutaway drawing was done for the July 2012 issue of National Geographic Magazine. Maps by Martin Gamache.