New Pyramid in Antarctica? Not Quite...

An Antarctic mountain with a unique, pyramid-like shape is suddenly internet-famous, with countless theorists contemplating its origin. Some are wondering whether an ancient civilization created the rocky, pyramidal structure, and others are pointing toward outer space, speculating about the involvement of aliens.

But Occam's razor — the idea that the simplest explanation is usually the right one — points to a far more mundane cause: Those steep, pyramid-like sides are likely the work of hundreds of millions of years of erosion, experts told Live Science.

"This is just a mountain that looks like a pyramid," Eric Rignot, a professor of Earth system science at the University of California, Irvine, told Live Science in an email. "Pyramid shapes are not impossible — many peaks partially look like pyramids, but they only have one to two faces like that, rarely four."

The pyramidal mountain, which doesn't have a formal name, is one of the many peaks that make up Antarctica's Ellsworth Mountains, which were discovered by the American aviator Lincoln Ellsworth during a flight on Nov. 23, 1935, according to a 2007 research paper that was published by the U.S. Geological Survey (USGS).

More specifically, the unnamed mountain — located at 79°58'39.25"S 81°57'32.21"W — is in the southern part of the Ellsworth Mountains in an area called Heritage Range, which is known for its extraordinary fossils, including those of Cambrian-period trilobites from more than 500 million years ago, according to a 1972 USGS report.

The mountain isn't that tall by planetary standards — just 4,150 feet (1,265 meters) — or a little less than one-fifth the height of Denali, the tallest mountain in North America, according to Google Earth. The mountain may not have Denali's height, but its unique pyramidal shape sets it apart, said Mauri Pelto, a professor of environmental science at Nichols College in Dudley, Massachusetts.

Freeze-thaw erosion likely led to its pyramid-like shape, Pelto said. This happens when snow or water fills up cracks within a mountain during the day. When night falls and temperatures drop, the snow freezes and expands, turning into ice. The expanding ice causes the cracks to grow, Pelto said.

This freeze-thaw erosion happens countless times, leading to the creation of larger cracks that can, eventually, cause entire rock sections to break off, he said. These forces likely also shaped other pyramidal mountains, including the Matterhorn in the Alps, he said.

Read more at Discovery News