Is there life on Mars? Evidence suggests there is
doi:10.1038/nindia.2018.137 Published online 28 October 2018
Prospects of finding life on Mars have brightened with the discovery of an extremophile — a microorganism that thrives in extreme environments — in a lagoon in central Spain, researchers recently reported at the European Planetary Science Congress in Berlin1.
The 'pink lagoon' (Laguna de Peña Hueca) — so called because its water is pinkish — has very high concentrations of salt and sulphur. The lagoon is considered a terrestrial analogue for chloride deposits found in the southern highlands of Mars, says one of the researchers, Rebecca Thombre of the Modern College in Pune, who visited the lagoon site on a travel grant from Europlanet.
Intrigued by the pinkish colour of the lagoon's waters, Thombre, along with Bhalamurugan Sivaraman of the Physical Research Laboratory in Ahmedabad and Felipe Gómez of the Centro de Astrobiología in Madrid, set out to find out why the lagoon's water is "candy-pink" by studying the physical characteristics and genetic sequence of the microorganisms isolated from water samples collected from the lagoon.
The researchers found the pink colour is derived from the red cells of Dunaliella salina EP-1, one of the most salt-tolerant extremophiles ever found.
Their study suggests that similar kinds of life could survive in similar inhospitable conditions on Mars and could easily exist below the recently discovered salty subsurface lake near the Martian south pole. "Underground pockets or lakes of water, even if highly salty, may be the best places (to look for life in Mars), if their analogues on Earth are any indication."
1. Thombre, R. et al. Extremophiles from Tirez and Peña Hueca: Implications for exploring habitability of Mars and Europa. European Planetary Science Congress, 12 (2018) https://meetingorganizer.copernicus.org/EPSC2018/EPSC2018-1180.pdf