Mars seems to have become one today desert cold and dry. But some 3.5 billion years ago – or a little more – its Atmosphere The surface of the planet was hot enough for liquid water to flow. In 1972, it was the Mariner 9 mission that first revealed the Martian landscape studded with ancient riverbeds. For decades, researchers have accumulated evidence that confirms this. Yet they still do not know what causes this infection.

It is generally believed that the depletion of the Martian atmosphere carbon di oxide (CO)₂) could have been the reason for this spectacular drying of red Planet, Although, University of Chicago researchers (USA) suggest that the transition from a hot, humid planet to a cold, dry planet may be the result of the loss of another component of the atmosphere. Which one ? The question remains.

Researchers study thousands of photos returned by multiple people Missions Launched to Mars these last years. They analyzed how river beds overlap and how they are changed. All in order to reconstruct the river history of the Red Planet over the past billions of years. With the idea of ​​combining these analyzes with simulations of climatic conditions. To finally determine which one is best suited for observations made by flying machines on Mars.

better target habitable planet

It was in this process that researchers realized that CO. change in the amount of₂ – One powerful greenhouse gas, we know only too well – the atmosphere of Mars did not differ substantially from the climatic conditions of the Red Planet. In other words, CO₂ It doesn’t seem to be the main driver of the wet/dry transition on Mars. Another major factor may have intervened. “We don’t know what this factor is, but it must be present in large quantities to explain the results. ,University of Chicago geophysicist Edwin Kite says, a sent,

It seems that there are several alternative solutions. The first of these is the one proposed last year by the same researchers. presence of a layer of clouds Thin and icy high in the atmosphere of Mars, which would have trapped the heat. Other scientists have suggested that the hydrogen released from within the planet once formed CO. can be negotiated with₂ in the atmosphere to absorb infrared rays and heat the planet.

Persistence Rover, which currently hovers over the Red Planet’s ground, may provide additional clues that will help debunk at least some of the hypotheses. As researchers know, for a planet, maintaining stable conditions – and conducive to life – for millions, even billions of years, is not easy. And solving the mystery of Mars drying out may eventually allow them to better target potentially habitable exoplanets.