Cryptic region

An area near the South Pole, which remains unusually dark as the area is covered with water and carbon dioxide (CO₂) ices and frosts. The reason why it remains darker is unclear.

Several theories have been proposed, which include:

• change in ice properties.
• unusual amounts of cracking in the ice in this area.
• geometrical photometric effects.
• cold trapping of water vapour into frost.

However, none of these speculations clearly explain the mystery.

At one time the Cryptic region was thought to be associated with the land form below it. While most of the region is over the South Polar Layered Terrain, parts of it spread into other geologic regions. Further, other similar areas of South Polar Layered Terrain did not have this strange darkness, so this explanation failed.

This article is a stub. You can help Marspedia by expanding it.