Fast Facts
One of the Lab team's researchers usually photographs Earth landscapes outside of the lab, but we've never seen anything like this. It's so alien.
This photo shows many shallow pits in the bright cap of carbon dioxide ice, often called the "Swiss cheese terrain." A deeper, circular hole goes through the ice and dust, which could be an impact crater or a collapse pit.
These pits form because of a cool Martian phenomenon. The cap is mostly carbon dioxide ice, which can sublimate—going directly from solid to gas—when heated by the Sun.
The "cheese" itself isn't very deep, with estimates suggesting it's only about 8 meters (26 feet) thick. Underneath lies another layer, this time of water ice. The whole system is dynamic, with some areas growing new CO2 frost in flatter regions while the pits expand.
This two-layered structure supports the idea that Mars once had a much thicker and wetter climate.
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