For some time now, and in particular thanks to data collected by Mars rovers, we have known that Mars once had lakes of liquid water, often nested in the hearts of ancient impact craters. Jezero Craterthat Perseverance is currently passing through is a perfect example of this, especially due to the presence of a sedimentary succession of deltaic origin.
The study of these ancient lakes, whose existence dates back several billion years, is extremely important to determine the climatic conditions that prevailed on the planet at the beginning of its history. They are also favorite places to hope to find traces of primitive life. Because the lake sediments, often clayeythey are the most suitable means for the conservation of biological molecules.
Ancient Martian lakes are identified, of course, thanks to satellite data and images acquired from orbit by the various probes that constantly scan the Martian surface. Today, about 500 ancient lakes have been listed on the surface of Mars. But for some scientists, this figure is certainly far below reality.
70% of ancient Martian lakes still unidentified
In fact, more than 1,000 Paleolacs could have escaped the eye of the satellites. It all sounds like one big story. It should be noted that almost all of the ancient lakes identified so far are particularly large, usually over 100 km.two. However, on Earth, only 30% of lakes fall into this category. The remaining 70% are much smaller.
If we take this statistic to hold for the Red Planet, it’s very likely that we’ve missed the vast majority of Martian lakes so far. This gap could simply be explained by the difficulty of identifying these small ancient basins using satellite images…