ESA’s Mars Express has returned a stunning close-up of the Syrtis Major region on Mars.
Syrtis Major, discovered in 1659 by Christaan Huygens, is a province on Mars dating back billions of years. This region can be spotted from Earth with relatively small telescopes – the near-circular dark area on the planet stretches over 1300 x 1500 km.
Once thought to be a sea of water, the region is volcanic in origin. Now, we know that the changes in its shape are due to dust and sand being blown around in the wind.
The new view of the region, taken by ESA’s Mars Express orbiter, shows 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 colors 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 on the image. 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 on the image has a small central peak and contains a small dune field of darker-toned dunes to the east of its floor.
Information on the number and size of craters can be used to date the volcanic province and suggests an age of over 3 billion years.