Mars is a wondrous world full of mysteries. We’re getting closer to solving some of them, but others remain baffling.
Take the bizarre phenomenon of brain terrain for example. Consisting of intricately sculpted, whorled ridges and troughs, it resembles the wrinkled surface of the human brain.
Exactly what causes the landscape to develop this way is unknown.
Brain terrain is found in the Martian mid-latitudes, where the northern plains meet the southern highlands. It occurs in craters, valleys, and on formations known as lobate aprons; ice-rich features that form at the base of tall structures such as crater ridges and mesas.
Since brain terrain occurs where there is ice, scientists think its formation might have something to do with the way frozen water behaves.
One possibility is that the ridges, around 4 to 5 meters (13 to 16 feet) high, and furrows are carved out by ice flows somehow.
Another possibility is that the formations are the product of water ice under the surface. Sublimation of the ice through fractures could cause the ground above it to collapse, resulting in pitted, textured terrain.
A third hypothesis suggests that the terrain could be created similarly to “stone sorting” processes here on Earth. When the ground freezes, it expands, heaving and lifting the sediment; when the frost thaws, the loosened sediment falls back, and the different stones within tend to fall together according to size. Here on Earth, over repeated freeze-and-thaw cycles, this creates patterns on the ground.
There’s very little here on Earth analogous to Mars’ brain terrain, but scientists have found something similar-ish in the Canadian High Arctic on much smaller scales, which they call terrestrial brain terrain.
Its discovery suggests that sublimation or stone-sorting are plausible mechanisms for the terrain’s formation, but we don’t really understand terrestrial brain terrain fully, either.
Since it’s a bit more accessible than Mars, though, perhaps it’s worth taking a closer look at what’s happening here on Earth, to try and understand an alien world millions of kilometers away.