Malcom was right

In extreme conditions, iife finds a way...

In a surreal landscape of colours, dominated by luminescent ponds of yellows and greens, boiling hot water bubbles up like a cauldron, whilst poisonous chlorine and sulphur gases choke the air. Known as the “gateway to hell”, the Danakil Depression in Ethiopia is scorchingly hot and one of the most alien places on Earth. Yet a recent expedition to the region has found it is teeming with life.

In the Dallol crater, the geothermal activity increases the temperature even further, so the brine water reaching the surface is about 100C. As well as the sweltering heat, the scientists have to cope with toxic hydrogen sulphide gas, not to mention chlorine vapour burning their airways and choking their lungs. They must all wear gas masks to work there for any period of time.

In March 2017, Cavalazzi’s lab and their colleagues found life in Danakil, after they managed to isolate and extract DNA from bacteria. They found that the bacteria are “polyextremophiles”, which means they are adapted to extreme acidity, high temperatures and high salinity all at once. It is the first absolute confirmation of microbial life in the Danakil acidic pools.

One of the scientists’ discoveries looks set to establish a new record. The team found life in a pool where the acidity was measured as zero pH. That pool is the most acidic place where life has been found on Earth. The previous record was in the Rio Tinto, a river in Spain that has a pH of 2.

Microbes discovered in Yellowstone and other hydrothermal environments have evolved adaptations to help them survive. These include having proteins and enzymes that are more chemically stable at higher temperatures. This can be achieved by having more bonds and connections between amino acids, the building blocks that make up proteins. It may be that the bacteria in the Danakil Depression hot springs have acquired similar adaptations.

Whatever the case, the scientists’ findings may help us understand how life could have arisen on other planets and moons. “On Mars, you have mineral deposits and sulphate deposits similar to those seen in the Danakil Depression. You also have active brine flowing periodically,” says Cavalazzi. So by studying in which extreme Earthly environments life can survive, and how it does so, we can start to figure out which regions of planets like Mars might be habitable.

http://www.bbc.com/future/story/20170803-in-earths-hottest-place-life-has-been-found-in-pure-acid