In search of a clue to the mystery of whether life on Mars is possible, scientists have devoted a lot of time to studying the Chilean Atacama Desert. This is one of the most destructive places on Earth - the cold high mountains, the absence of vegetation and incredible dryness. It has not rained in Atacama for centuries, and when this happens, not life, but death comes to the desert - and the scientific community was extremely surprised by this discovery.
The last time officially recorded rains fell over some areas of the Atacama on March 25 and August 9, 2015, and then on June 7, 2017. The water quickly came and just as instantly left, so the scientists had only to explore the soil moistened with it. And they saw the greatest tragedy, akin to the extinction of dinosaurs, because wetting the earth literally killed 85% of the living creatures in it. They were microbes adapted to the super-arid desert climate.
Before the rains, scientists managed to discover and study one and a half dozen of the most ancient microbes with unique biochemistry. They have evolved for centuries to survive in a completely moisture-free environment. And they achieved success, becoming almost the only stable form of life in this desert. But as soon as the rain passed, the researchers barely found only 2-4 surviving microbe species. The rest died from osmotic shock; excess moisture left them no chance of salvation.
If you imagine that there is life on Mars, it will be very similar to the Atacamian microbes. And, as we now understand, it will be extremely vulnerable to changes in the familiar environment - even when it comes to water, the source of life in the Universe.