Strange underground polygons on Mars hint at Red Planet's wet past

A black and white image of Martian terrain.

Buried dozens of meters under the equator of Mars is a large honeycomb pattern similar to what's found near Earth's frigid poles.

Each crevasse spans 70 meters (230 feet) — about half a football field — and is bordered by 30-meter-wide (98-feet-wide) slurries of ice and mud. It's likely, scientists say, that this material is somewhere between 2 billion and 3.5 billion years old. The patterns were spotted in the data sent home by China's now-incommunicado Zhurong rover which explored an expansive, bumpy region north of Mars' equator named Utopia Planitia.