Saturday , June 25 2022

"Martian" lagoons in the driest desert on earth – Chihuahua News – Entreline


The Atacama Desert, in Chile, hides in its center the driest place on earth. For the first time since there are records, it has rained in Atacama's hearted heart for the last three years, and chemical lagoons have formed that have changed the area's ecological balance. The study of Atacama's new lagoons allows us to better understand Mars's astrobiological development.

The Atacama Desert, located between the Andes mountain range and the Pacific Ocean, in northern Chile, is the driest and oldest desert on earth. Rain, however, is not uncommon in Atacama, as the desert encompasses geographical areas of cultivation and pastures and coastal areas, which periodically generate news about flowers covering areas of Atacama. But the Atacama desert has a hearted heart where it has been at least 500 years since no rain has been recorded. The soils in this extremely dry desert center are very salty and rich in nitrates, sulphates and perchlorates. And while life is barely here, it has been successful. Its inhabitants are microorganisms that can tolerate the high levels of dehydration and radiation that have characterized the Atacama desert for the last 15 million years.

In the decade of 2015-2017, and for the first time since we have rainforests in the area, it has rained significantly in Atacama's hyperdrima heart. As a result, a set of hypersalin lagoons that have lasted for several months has been formed for the first time in the area. In a study published today, a group of Spanish researchers from the Center for Astrobiology, mixed center for CSIC and INTA in Madrid, coordinated our research on lagoon geochemistry and microbiology.

Our group has discovered that, contrary to what can be expected intuitively, the contribution of water has not caused a flowering of life in Atacama. On the contrary, the rain has caused a huge devastation in the microbial species that inhabited these sites before precipitation. The eruption area reaches 85% as a result of the osmotic tension that caused the sudden excess of water: the autochthonous microorganisms, perfectly adapted to live under extreme dry conditions and optimized to recover their scarce moisture, have not been able to adapt to the new conditions for sudden flooding and has died of excess water.

Our study of the effect of lagoon formation in the Atacama Desert's high-dried heart, probably a consequence of the global climate change that the earth suffers, also serves to create an analogy with what happened to Mars at the time because its own global climate change left it without liquid water and helps explain the fate of any primordial marian biosphere. Mars had a first geological period, Noeico (between 4.5 and 3.5 billion years ago), under which it held a lot of water on its surface; We know this from the amount of hydrogeological evidence preserved, in the form of all-in-one hydrated minerals on the surface, traces of rivers, lakes, delta and perhaps a hemispheric sea on the northern plains. If life ever occurred on Mars, it must be during this first period, which coincides with the moment the origin of life has on earth. Later, Mars lost its atmosphere and its hydrocolor, and it became the dry and expensive world we know today. But sometimes during the Hesperian period (between 3.5 and 3 billion years ago) large volumes of water dug their surface in the form of overflow channels, the largest in the solar system. If there were still microbial societies that resist the extreme drying process, they would have been exposed to osmotic stress processes similar to those described in Atacama. Therefore, the Atacama study helps us to suggest that the relapse of liquid water on Mars could have contributed to the disappearance of Mars Life, if ever existed, instead of representing a possibility of regrowth of resilient microbiotics.

In the same way, our work gives a coherent explanation of the negative results achieved by the Viking Probes on the Mars area of ​​the 70s of the last century, the only time we have sought life on another planet so far. The Viking experiments were performed by incubating samples of the Martian surface in aqueous solutions to try to provide a favorable environment for potential martian microorganisms to accelerate their metabolism and grow. However, our work suggests that all types of living creatures that could survive even today on Mars would be perfectly adapted to the extreme dryness of the Mars surface, and would therefore immediately have died of osmotic shock within the Viking instruments. Future experiments in the quest for life on Mars should take into account the devastating effects that the first rains of the centuries have produced on the microbial communities living in the Atacama Desert's hyperdriven heart.

Source: The country

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