Trending science: NASA reveals ‘strongest evidence yet’ of liquid flowing on Mars
Speculation was rife last Monday morning that the space researchers were preparing to announce some big news. And they didn’t disappoint. On Monday afternoon, NASA presented to the world the strongest evidence yet that liquid flows on Mars, making it increasingly likely that life may exist there. ‘Following the water’ The findings are part of NASA’s ploy of ‘following the water’ in the search for other life in the universe. According to John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate, the research offers convincing science that validates what they have long suspected. He noted, ‘This is a significant development, as it appears to confirm that water – albeit briny – is flowing today on the surface of Mars.’ Hydrated salts may explain mysterious dark streaks Using an imaging spectrometer on NASA’s Mars Reconnaissance Orbiter (MRO), researchers detected ‘signatures of hydrated minerals on slopes where mysterious streaks are seen’. The downhill flows are known as recurring slope lineae (RSL) and have often have been described as possibly related to liquid water. However the new findings of hydrated salts on the slopes point to what that relationship may be to these dark streaks. NASA says that the hydrated salts would lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt more rapidly. Scientists say it’s likely a shallow subsurface flow, with enough water wicking to the surface to explain the darkening. ‘We found the hydrated salts only when the seasonal features were widest, which suggests that either the dark streaks themselves or a process that forms them is the source of the hydration. In either case, the detection of hydrated salts on these slopes means that water plays a vital role in the formation of these streaks,’ said Lujendra Ojha of the Georgia Institute of Technology in Atlanta, lead author of a report on these findings published on 28 September by Nature Geoscience. Earth meets Mars: contamination concerns The news has naturally generated huge interest within the science media and excited speculation abounds. One article in Nature, citing a joint review from the US National Academy of Sciences and the European Science Foundation, however sounds a word of caution. It notes that finding extraterrestrial life will be far from easy and perhaps not for the reasons we think... The technological and budgetary challenges may actually be trumped by the ‘contamination factor’: ‘The need to protect any possible Martian biosphere from Earthly contamination, the review’s authors wrote, could “prevent humans from landing in or entering areas” where Martian life might thrive.’ National Geographic underlines the fact that finding evidence for flowing water is not the same as finding life. It also echoes concerns about Earth microbes contaminating the Martian surface, quoting Bethany Ehlmann, a planetary geologist at Caltech in the US: ‘It’s hard to get a spacecraft clean enough to send a lander or rover there right now.’ Whatever the next steps are, the excitement over these findings remains palpable. We seem to be one step closer to answering the question: Is there life on Mars? For further information, please visit: NASA article Brine on Mars study in Nature Geoscience
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