Penitentes

These strange snow formations are called penitentes (or nieves penitentes). The tall, thin spikes are typically blade-shaped and can be found at high altitudes above 13,000 feet and are made of hardened snow or ice. The blades usually are oriented toward the sun.

It takes rather precise climatic conditions to produce penitentes.

In 2006, researchers were able to create penitentes in the lab, a first. The American Physical Society reports, "After some false starts, the apparatus that worked was a large horizontal freezer with a clear Plexiglas top. The team cooled the air by sending it through liquid nitrogen and also controlled humidity. They shined a flood lamp onto a block of snow or ice in the freezer and produced one- to five-centimeter

-tall spikes on the block within a few hours."

"Understanding their growth may give researchers insight into the process of glacier “evaporation” and may shed light on similarly-shaped micro-spikes that appear in materials like those in solar-powered energy cells," states the researchers. It may also help them in understanding how to preserve glaciers in a warming world.