Mysterious Landforms Emerge on Mars: Here’s How

The European Space Agency’s (ESA) Mars Express has made an intriguing discovery in the southern polar region of Mars, revealing mysterious formations known as “cryptic terrain.”

These unusual landforms, located in areas darker than the surrounding icy landscape, are part of Mars’ seasonal polar caps, which consist of both carbon dioxide ice and a small amount of water ice.

As spring approaches, the ice in these polar regions sublimates—transforming directly from a solid state into gas. This rapid sublimation releases large amounts of gas into Mars’ thin atmosphere. The process reverses in autumn, with vapor condensing and the polar caps expanding. These freeze-thaw cycles result in the formation of the cryptic terrain.

The Mars Express’ High Resolution Stereo Camera (HRSC) captured this terrain in a region called Australe Scopuli during the southern hemisphere’s spring season.

 

About Australe Scopuli

Australe Scopuli is an area covered by layered ice deposits, which contain varying levels of dust beneath their smooth surfaces. At the center of this region lies the cryptic terrain, which appears darker compared to the surrounding ice.

The captured image reveals a landscape marked by polygonal shapes, with the edges of these polygons covered in bright frost. Similar patterns, found in Earth’s Arctic and Antarctic regions, suggest the presence of water ice beneath the surface.

Additionally, bright and dark fan-shaped deposits are seen in the direction of the prevailing winds. In early spring, sunlight penetrates the transparent layer of carbon dioxide ice, warming the surface below. This heating creates pressure from trapped gases, which eventually crack the ice. When the gas jets through the surface, it carries dark dust from beneath, and as the dust settles, it aligns with the wind’s direction.

This discovery sheds light on the dynamic processes shaping Mars’ icy polar regions.