Exposure of South Polar Layered Deposits (Natural Colors; credits: Lunexit)

Extensive Layered Deposits are found in both Polar Regions of Mars and are thought to contain evidence of recent climate changes like ice ages on Earth.

Radar observations suggest that the NPLD - as well as the SPLD - are composed mostly of water ice, but many layered exposures, including this one, appear to be covered by a layer of dust that protects the underlying water ice from further erosion. The SPLD are more extensive than the NPLD, and have generally been less active recently.

The greater age of the SPLD is indicated by the higher density of craters on its Surface; as a matter of fact, a cluster of small craters is visible above center in this image. Also visible are widespread polygonal fractures, evidence of water ice expansion/contraction below the Surface.