Researchers have identified a new, drier place on Earth in the Atacama Desert, a region in Chile already recognized as the driest in the world. They have also found evidence of life at the site, a discovery that could have far-reaching consequences for the search for life on Mars.
For more than a decade, the Yungay region had been considered the driest area of the hyper-arid Atacama Desert, with conditions close to the so-called "dry limit" for life on Earth. Various academic papers have been published on the extraordinary characteristics of this place and its relevance to astrobiologists as an analog of conditions on Mars. However, after a more systematic search in this desert, a Chilean research team has now found a new site, María Elena Sur (MES), which it describes as "much drier" than Yungay.
Lead author Armando Azua-Bustos, an environmental research scientist and biologist at the Blue Marble Institute for Space Science in Seattle, says the team found that MES has a mean atmospheric relative humidity (RH) of 17.3 percent. cent and RH in soil with a constant 14 percent at a depth of one meter. This value matches the ground with lower RH measurements taken by the Curiosity rover in the Gale crater on Mars, establishing the fact that conditions at the site are as dry as those recently found on the Martian surface.
"Surprisingly, we found a number of viable bacteria species in the soil profile in the MES using a combination of dependent and independent molecular methods, revealing the presence of life in the driest place in the Atacama desert reported to date", Azua-Bustos says in a statement published by astrobio.net.
The team used microsensors, including atmospheric temperature and relative humidity logs, to take detailed measurements of the microenvironmental conditions at the MES site.
He also characterized the geochemical composition of the soils at the site to reveal the presence and type of microbial species capable of surviving under these conditions.
The results are presented in the journal Environmental Microbiology Reports. For Azua-Bustos, the fact that the conditions of the MES site, in terms of dryness, are the closest possible to those of Mars means that it is one of the best analogue models on Earth to understand and investigate the possible existence of life microbial in the Martian subsoil.
"This also means that if you want to test the next generation of robots, instruments, and other sensing techniques and technologies in an environment like Mars, this is one of the best you can find, as it has many of the key features that are available. they want to find it on the red planet, "he says.