What causes these spooky ice formations in the desert?

The Atacama Pathfinder Experiment telescope, or APEX, is on Earth, but surrounded by ice spikes that make the landscape look decidedly alien. These "sculptures" are natural formations known as penitentes. And they form where it's very cold and very dry. » 1/03/14 4:40pm 1/03/14 4:40pm

The mysterious icy figures who haunt the Andes

These mysterious ice figures form only at high altitudes, and only under very specific conditions. In the Andes, they're called "penitentes," and fields of them can stretch for miles. » 10/12/12 2:03pm 10/12/12 2:03pm