About 3.7 billion years ago on Mars could exist a stable river to a depth of several meters, according to a new study, published in Nature Communications. This was pointed out to pictures of layered rocks on the walls of the Hellas crater taken by the Mars Reconnaissance Orbiter.
The Hellas basin located in the Martian southern hemisphere, has long been of interest to planetologists. This is one of the largest impact craters in the Solar system with a height difference between the edges and the bottom more than 9 thousand meters. Various forms of relief, still preserved, attest the presence of ancient Mars network of ancient rivers, deltas, and channels of outflow, and mineral matter indicate that the region was once a very large lake. However, detailed descriptions of alluvial deposits Maiskogo period, which started 4.5 billion years ago and lasted for about 1.1 billion years, still existed.
Group Sales Francesco (Francesco Salese) from the University D’annunzio in his study focused on the rocky cliff with a height of about 200 meters in the North-Western part of the crater Hellas. It is inside a shock structure with a diameter of about 2000 km, which is also plain that contain sedimentary rocks Noiseu era, phyllosilicates rich in magnesium and iron. The researchers studied images taken by the camera HiRISE, installed on Board the Mars Reconnaissance Orbiter, and the data of the laser altimeter MOLA on the topography of the area, then built a digital model of the terrain. This model of planetary scientists compared the landforms found on our planet.
Due to the fact that the researchers were able to recreate in detail the terrain of a rocky cliff, they could see layered rocks on its slopes and channel shapes. They had a great resemblance to sedimentary rocks on Earth, formed when water flows. Topographical analysis of the area showed that probably around 3.7 billion years ago in the crater of Hellas flowed the river to a depth of three meters. The main stream is constantly shifting, which formed sandbanks, which managed to see a scientist. The group is the Sales notes that these rivers were constant — the authors, they were, dozens or even hundreds of thousands of years. Therefore, sedimentary rocks of this period may become a promising target for the search for evidence of ancient life on Mars.
The work of scientists is another evidence in favor of the fact that billions of years ago conditions on Mars were much more favorable than it is today. So, in the past researchers have shownthat on the surface of Mars in the period from 3.6 to 1 billion years ago was renewed streams and hydrogen it was enough to sustain underground life for hundreds of millions of years.