Cryptic Terrain (MULTISPECTRUM; credits: Lunexit)

There is an enigmatic Region near the South Pole of Mars known as the "cryptic" terrain. It stays cold in the Spring, even as its albedo darkens and the Sun rises in the sky.

This Region is covered by a layer of translucent seasonal CO2 ice that warms and evaporates from below. As CO2 gas escapes from below the slab of seasonal ice it scours dust from the surface. The gas vents to the surface, where the dust is carried downwind by the prevailing wind.

The channels carved by the escaping gas are often radially organized and are known informally as "spiders".