Nasa scientists find evidence of flowing water on Mars | Science

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    Nasa scientists find evidence of flowing water on Mars
    ▻http://www.theguardian.com/science/2015/sep/28/nasa-scientists-find-evidence-flowing-water-mars

    Liquid water runs down canyons and crater walls over the summer months on Mars, according to researchers who say the discovery raises the odds of the planet being home to some form of life.

    The trickles leave long, dark stains on the Martian terrain that can reach hundreds of metres downhill in the warmer months, before they dry up in the autumn as surface temperatures drop.

    Images taken from the Mars orbit show cliffs, and the steep walls of valleys and craters, streaked with summertime flows that in the most active spots combine to form intricate fan-like patterns.

    Scientists are unsure where the water comes from, but it may rise up from underground ice or salty aquifers, or condense out of the thin Martian atmosphere.

    “There is liquid water today on the surface of Mars,” Michael Meyer, the lead scientist on Nasa’s Mars exploration programme, told the Guardian. “Because of this, we suspect that it is at least possible to have a habitable environment today.”

    #Mars #espace

    Lyco
    • @lyco
      Lyco

      Why hunting for life in Martian water will be a tricky task
      ▻http://www.nature.com/news/why-hunting-for-life-in-martian-water-will-be-a-tricky-task-1.18450

      The agency’s first — and to date only — missions to Mars explicitly in search of life were the twin Viking landers, which landed on the red planet in 1976. All others since have focused on finding signs of life from Mars’ ancient past rather than its present. If even sterilized robots cannot be trusted to venture into [restricted] Special Regions, what about microbe-riddled humans? If astronauts shall only be allowed to visit subpar locales to search for life on Mars, can NASA or any other entity justify the tens to hundreds of billions of dollars required to send them there? If a human crew lands in an area thought unpromising for biology but discovers habitable conditions or even something living there, would they have to immediately relocate, or even pack up their rocket and launch back to orbit? These and other unanswered questions show how in many ways, discovering a present-day Martian biosphere could be both the realization of NASA’s wildest dream and its worst nightmare. They explain as nothing else can the otherwise inexplicable fact that in the quest for extant life on Mars NASA has been judiciously avoiding the very places where it may most likely be found.

      Lyco
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