A place on Earth where everything’s dead

So far, the Earth is the only place in the universe where life has been proven to exist. But even on our planet, there are places that life cannot survive. The geothermal fields in the Ethiopian region of Dallol are one of these places. Near the Danakil Depression in northeastern Ethiopia, close to the border with Eritrea, a volcanic explosion in 1926 formed a crater with a diameter of 30 meters (98 ft), exposing hot salt springs. The emerging water is 70°C (158°F) and extremely acidic with a pH value below 1. At the same time, the air temperature is very hot at 45°C (113°F).

In the language of the Afar people living in this region, the word Dallol apparently doesn’t mean “dissolution” or “disintegration” for nothing. After very thorough testing, researchers are now reporting that they could find absolutely no living cells here, even though the area is constantly being inundated with microbes due to wind and humans in the very biologically active surroundings.

The scientists believe two factors are decisive in killing any living organisms: first, the presence of chaotropic magnesium salts (which break the hydrogen bridges and denature biomolecules) and the simultaneous effects of hypersaline, hyperacid, and high-temperature conditions.

These findings could also be of interest for astrobiology: “We would not expect to find life forms in similar environments on other planets,” says Purificación Lopez Garcia, one of the researchers, “at least not based on a biochemistry similar to terrestrial biochemistry.”

The many colors of the Dallol pools are caused solely by mineral substances (photograph: Puri López-García)

 

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