Mars Express reveals wind-blown deposits on Mars

Syrtis Major, discovered in 1659 by Christaan Huygens, is a volcanic province on Mars.

Newly released images of a part of Syrtis Major seen from ESA’s Mars Express orbiter show lava flows that flooded the older highland material, leaving behind buttes – isolated hills with steep sides that were too high to be affected.

They can be identified by their lighter colours and their eroded state, and some even show ancient valleys on their flanks.

Individual lava flows, filled craters and partly-filled craters can be made out in the images. The prevailing wind direction can be seen from the dispersal of the lighter-toned dust and darker-toned sand in and around the craters and buttes. The smaller craters illustrate this clearly.

The largest crater in the pictures has a small central peak and contains a small dune field of darker-toned dunes to the east of its floor.

The number and size of craters can be used to date surfaces in the Solar System because craters slowly accumulate as impacts occur over time. This information can be used to date the volcanic province and suggests an age of over 3 billion years. (ESA)