Look at This: Curiosity Finds Evidence of Ancient Martian Stream

By Sophie Bushwick | September 28, 2012 11:00 am

water on Mars

When water flows over stones, it smooths them out and carries them in its path. Even when the steam has long since dried up, the gravel it leaves behind provides distinct evidence of the water’s former presence. And now the Curiosity rover has found tell-tale gravel embedded in the Martian bedrock, small stones rounded by water and too large for wind to have transported—rocky proof of water’s presence on the Red Planet. Although previous photos suggested that water once flowed on Mars, the rocks in outcrops like the one pictured here, dubbed “Hottah” after Canada’s Hottah Lake, are the most definitive evidence of water on Mars that we have ever found.

A piece of the embedded gravel, called a clast, is circled in the close-up of Hottah below.

water on Mars

Image courtesy of NASA / JPL-Caltech / MSSS

  • Miles Archer

    Looks like ancient concrete. Are we sure the Romans didn’t make it to Mars?

  • obsidian100

    I hypothesize that the sun was much Hotter in the earlier days of the solar system putting the ‘golden zone’ at Mars . It is our turn now with Venus next in line….

  • Bob

    Perhaps the solar wind and other things contributed to the erosion, and there wasn’t water at all.

  • Magoonski

    @Bob Mars has icecaps, and yes they are H2O.

  • floodmouse

    Would other liquids leave the same marks? Makes sense there was water on Mars. Could a planet with different chemistry/temperature/pressure have other flowing liquids (not H2O) that would leave the same kind of track in the rock?

  • Jake Parks

    As for the hypothesis that the Sun was much Hotter in the earlier days: the Sun (and all stars) burn hotter and brighter as their lives go on, so the ‘golden zone’ would start closer (Venus) and move outwards from the Sun over time (Mars).

  • Papabear

    @Miles Archer No…it was the Mayans. They built a spaceport at Apocalypse Island

  • tsmorro

    @obsidian100 …. i sort of agree. although it seems more likely that, given the relatively short time that the planets have existed relative to the lifespan of our star, planets may begin near their star(s) and slowly rotate farther and farther out as time goes by….so mars is our future and venus is in the state that earth once was. who knows though


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