ESA has released new images of a crater with a diameter of about 70 kilometers in the region of the planet Mars called Margaritifer Terra. This is a composite of two images captured by the Mars Express Space space probe’s High Resolution Stereo Camera (HRSC) instrument almost exactly 10 years away in March 2007 and February 2017. The crater and the surrounding area show yet again evidence of the presence of liquid water in Mars’ distant past.
Margaritifer Terra is a region of Mars’ southern hemisphere full of craters with a chaotic terrain, channels and deposits of sediments suggesting that in the past there were massive floods. A very long time has passed since those events and today there are also signs of wind erosion. This region is at the northern edges of Noachis Terra, where there are some of the oldest and most cratered terrains on the red planet.
The crater in that area contains light-colored materials that according to scientists that’s an exposed bedrock. Both within and outside the crater chaotic terrains are visible characterized by randomly-oriented blocks separated by channels. A similar terrain exists also in the area on the right in the image above, part of an area called Erythraeum Chaos, where in a remote past there could be lakes.
According to scientists, chaotic areas are formed when underground caves melt due to the heat generated by volcanic activity, also existing in Mars’ distant past, with the result that water is suddenly released. When water flows away the surface collapses over the newly created cavities leaving the chaotic terrain with the remaining plateaus, which are separated by a network of deeply-carved valleys.
The sediments on the bottom of Erythraeum Chaos were perhaps transported through the Paraná Valles region, east of the crater, and deposited there. The Paraná Valles, along with the Loire Valles at the northwest of the crater, form one of the widest and best integrated Mars valley systems. In all these areas there are still many traces of lakes and river systems that existed over 3.5 billion years ago.
This research is part of the reconstruction of Mars’ remote past. In this case, to study the traces of lakes and rivers at Margaritifer Terra and Erythraeum Chaos the scientists put together images separate by a decade, confirming the usefulness of a mission that’s now over 13 years long such as the Mars Express space probe’s. The collected data keep on remaining available to researchers and may be useful even after years to improve our knowledge of the red planet.