Researchers at the Centre of Astrobiology have identified microorganisms that live inside salt deposits in the acidic and ferrous environment of the Tinto River in Huelva, Spain. The extreme conditions of these microniches appear to be similar to those of the salt deposits on Mars and Jupiter's moon, Europa. This possibility should be borne in mind on missions operating in these places, such as Curiosity.
The high doses of radiation, lack of moisture and extreme temperature and pressure on the surface of Mars make the development of life difficult. Within this hostile environment, scientists are searching for "friendlier" niches that could encourage life. One of the candidates is the salt deposits.
A team from the Centre of Astrobiology (CAB, INTA-CSIC) has analysed this kind of environment on Earth: the salt deposits associated to a mineral with sulphur and iron named natrojarosite. It can be found in the Ro Tinto basin in Huelva and is very similar to one detected on Mars: jarosite. Its presence reveals the past or present existence of water.
"The salt deposits are good 'hosts' for biological remains and even life itself in extreme circumstances," as outlined to SINC by Felipe Gmez, coauthor of the study published in the 'Planetary and Space Science'.
"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," explains the researcher.
With the help of microscopic techniques and molecular ecology, the team has discovered a film of bacteria and algae living in salt 'microniches' invisible to the naked eye. Up to five different morphologies have been found of microorganisms belonging to the Dunaliella and Cyanidium genera.
The deposits analysed have been formed by layers each with a width of just a few millimetres. They make up a "completely diff
FECYT - Spanish Foundation for Science and Technology