Numerous scientific discoveries suggest that ancient Mars had a humid climate and watery rivers flowing on the planet's surface. With all this, it is believed that in the past the Sun was one-third colder, so astronomers have been trying for a very long time to create a model of the planet's development and reproduce scenarios according to which there would be enough heat on Mars to keep water in liquid form.
Today's main theory is that the planet had a denser layer of carbon dioxide in the atmosphere, which formed a kind of 'greenhouse blanket' that contributed to the temperature rise on Mars in the past. However, according to a new analysis of data from the Curiosity rover, Mars 3.5 billion years ago did not have enough carbon dioxide for this, that is, there was simply no temperature necessary to thaw glaciers.
Despite the fact that the rover discovered the rocks of one of the Martian lakes and a presumptive habitat for microorganisms, Curiosity did not reveal carbonate materials in the samples, which suggests that at the time of the lake's existence 3.5 billion years ago, the presence of carbon dioxide on the planet was quite insignificant.
“We were amazed at the lack of carbonate minerals in the sedimentary rocks studied by the rover,” said Thomas Bristow of NASA's Ames Research Center.
In the event that lakes on Mars in the past were really in a liquid state, such a discovery makes the question of the reasons for the thawing of glaciers much more acute. According to scientists, this suggests a different scenario for the development of the atmosphere on Mars in the past, which has yet to be investigated.
Sources: NASA
