MICROBES have been found flourishing in the saltiest earthly environment yet investigated for life. The find boosts claims that extraterrestrial life might thrive in equally salty niches on other planets and moons.
The salt-loving microbes were discovered in a Mediterranean sea-floor basin near the Greek island of Crete. 鈥淲e expected it to be sterile,鈥� says team leader Paul van der Wielen of Kiwa Water Research, a research institute in Nieuwegein, the Netherlands. 鈥淏ut the diversity is quite high, and most of the microbes identified are new species.鈥�
Called the Discovery Basin, the zone 3.5 kilometres under the ocean contains salt at the highest concentrations ever measured in Earth鈥檚 marine environment, more than twice as high as in the Dead Sea and 100 times as salty as ordinary seawater. Unlike the three other salty basins investigated by the team, which contain sodium chloride, Discovery contains magnesium chloride, a salt hitherto considered hostile to almost all life but which may well form surface deposits on other planets and moons ().
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鈥淚t doesn鈥檛 prove there鈥檚 life up there, but it widens the view that it might be possible,鈥� says van der Wielen. 鈥淲e now know that high concentrations of magnesium chloride are not a limitation on life.鈥� Van der Wielen says extraterrestrial surfaces covered with ice 鈥� like those already identified on Mars and Jupiter鈥檚 moon Europa 鈥� are most likely to have ultra-briny surface regions, created through evaporation.
