Scientists’ ideas about Marsi’s life have changed radically in less than 100 years of research. The Red Planet was initially thought to be inhospitable to life, like the Sahara in summer, but it later became clear that biological life as we know it could not exist on this planet for at least the last few billion years. Curiosity’s new findings revealed that there may have been life on Mars before this and how it died.

Many years of observation of Mars and remote study of its geology and soils lead us to think that about 4 billion years ago this planet had a large small ocean, lakes, rivers and streams. But then the climate changed dramatically and irreversibly. At the same time, what is happening on the planet and what its climate is like was also shown by the new findings of NASA’s Curiosity rover in the area of ​​\u200b\u200bthe 154 km wide Gale impact crater (Gale crater). This crater was formed by the fall of a meteorite 3.5-3.8 billion years ago.

Studies on rock samples taken from the floor of the crater with the rover’s onboard instruments (Sample Analysis on Mars and Tunable Laser Spectrometry) show that there is water in the crater and therefore minerals characteristic of a wet environment, such as clay and sulfate. and carbonates appeared there. Carbonates consisting of carbon and oxygen are thought to be the most valuable in terms of evaluating climate changes. Light isotopes of atoms quickly evaporate into the atmosphere, and heavy ones remain. By the ratio of one to the other, one can evaluate the climate, including temperature, acidity of water, as well as the composition of water and atmosphere.

“Isotope readings of these carbonates indicate extensive evaporation, indicating that these carbonates were likely formed in a climate that could support liquid water only for short periods of time. – said David Burtt (David Burtt) from NASA. — Our examples do not assume [існування] “The existence of an ancient environment with life (biosphere) on the surface of Mars, but this does not exclude the possibility of the existence of a subsurface or surface biosphere that began and ended before the formation of these carbonates.”

The condition of the carbonates suggests that habitable Mars died out in two processes, either simultaneously or separately. First, the planet began to periodically experience outbreaks of intense moisture evaporation. Second, the water began to freeze, leading to a spectacular increase in its salinity through evaporation. Nothing we know of could survive in such an environment, not even bacteria. There is hope for the search for life (at least microbial) deep below the Martian surface, but terrestrial science is unlikely to be able to do this in the next 10-15 years.