Microbial life has been found in the Mars-like environment of the Tinto River in Huelva, Spain, according to the Spanish Foundation for Science and Technology. Researchers from the Centre of Astrobiology have identified microorganisms that reside inside salt deposits in the acidic and ferrous environment of the river. They say that the extreme conditions of these “microniches” seem to be similar to those of the salt deposits on the Red Planet and Jupiter’s moon, Europa.
Spain’s Tinto River is characterized by deep red water that is extremely acidic and rich in heavy metals, ,according to Carleton College’s Marine Biology Laboratory. More than 5000 years of mining pollution have contributed to the river becoming an extreme environment. However, scientists believe that the presence of chemolithotrophic organisms, such as iron-oxidizing bacteria and sulfur-oxidizing bacteria, are responsible for the river’s condition.
While radiation, lack of moisture and a variety of other extreme conditions made Mars a tough place for life to develop, scientists think that salt deposits may be one of the “friendlier” niches on the Red Planet that could encourage life.
A team from the Centre of Astrobiology took a closer look at the salt deposits associated with a mineral named natrojarosite. The mineral can be found in the Tinto River and is vary similar to a mineral found on Mars called jarosite. Researchers say that its presence indicates the past or present existence of water.
“The salt deposits are good ‘hosts’ for biological remains and even life itself in extreme circumstances,” says coauthor Felipe Gómez. “The reason is that conditions in this environment remain less adverse than those of their surroundings given that they provide protection from radiation for example, and they keep moisture levels higher than outside.”
Gómez and his colleagues recently published their findings in Planetary and Space Science.
Using several different techniques, researchers found a film of bacteria and algae living in salt “microniches” invisible to the naked eye. The deposits examined have been formed by layers each with a width of just a few millimeters.
“The precipitated minerals could only have been formed in such an acidic environment like this one and it is still even home to microbial communities in development. In order words, here they find their ideal environment,” posits Gómez.
Gómez and his colleagues think that their discovery of microbial life in a Mars-like environment on Earth is a important step in evaluating the habitability potential of Mars.
“From the astrological point of view, salt deposits are of great importance and should be considered when searching for life on space exploration missions, like the current Curiosity rover mission on Mars,” says Gómez.