Swiss cheese terrain.
These pits form because of a cool Martian phenomenon.
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 numerous shallow pits in the bright cap of carbon dioxide ice, often referred to as 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—transitioning directly from a solid to a 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.
Curated resources
>>ESP_049972_0930 | A South Polar Pit or an Impact Crater? — I… | Flickr