When the first images of Mars reached Earth in the 60s and 70s, one could only see that the planet was deserted. This was the end of the theories about possible rivers or the presence of a Martian civilization on the surface. Moreover, subsequent studies have shown that the geological activities at the origin of several elements of the relief had already ceased ages ago.
In recent decades, however, we have been able to deduce from the results obtained from more sophisticated instruments such as rovers that there was still some activity on the planet Mars, and that it was therefore far from be a dead planet. Lately, further evidence of the presence of geological activity on the planet has been identified in an image taken by the MRO orbiter or Mars Reconnaissance Orbiter. The phenomenon in question is a relatively recent landslide that took place in a crater near Nili Fossae.
According to reports, the landslide was spotted in a larger image that was taken by the MRO's Context Camera or CTX. The image was recorded on September 21, 2018 and shows a 5 km wide area captured while the orbiter was at an altitude of 284 km.
The Context Camera or the wide vision device
The particularity of the CTX is that it has been developed to be able to obtain an enlarged view of the terrain where there are smaller rocks and minerals studied by the other instruments of the MRO. These instruments include, for example, the HiRISE or High-Resolution Imaging Science Experiment or the CRISM or Compact Reconnaissance Imaging Spectrometer for Mars. The CTX also constitutes mosaics of larger areas which are used when choosing landing sites for future missions.
One of the missions of the CTX is also the monitoring of certain sites at the level of the Martian surface which may undergo changes over time. This is also how the camera was able to detect what happened in the crater near Nili Fossae. It is one of the inner walls of the crater that has suffered a landslide since the last time the area was photographed.
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Geology in action
According to the scientists, what the image shows is the result of "mass movement process". This is the name given to the various movements of rocks and debris going down a slope, including avalanches, landslides or rock falls. Other images taken previously had already shown examples of these activities on the surface of the planet Mars.
We know that the crater in the image taken by the CTX is located northwest of the Jezero crater which will be the landing site of the NASA Perseverance rover. This landing site was selected because of the existence of the delta located near its western wall. Scientists say this delta is proof that a waterway flowed here billions of years ago, and it's the best place to look for fossilized remains.
In any case, as regards the geology of Mars, its study will allow us to understand the forces at work on the planet and thus to know more about the Martian environment.