“evidence of vast lakes, flowing rivers and deltas on early Mars..”

We may now be able to image our small blue planet from 31 million miles away, but there appears to have been a time when there was, at least, one other blue planet in the neighbourhood. According to data from the CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) instrument on Nasa’s Mars Reconnaissance Orbiter spacecraft, there is evidence of vast lakes, flowing rivers and deltas on early Mars, from about 4.6 billion years ago to 3.8 billion years ago. That corresponds to the time, 3.7 billion years or so ago, when it is believed that life already existed on Earth. Although recent discoveries suggest life might have existed here long before then..

  • And if, Giovanni Schiaparelli, were alive now he’d be turning in his grave screaming I told you so. As for, Percival Lowell, sure didn’t he even name the canal’s.

  • cynic

    Sadly the free water persisted for perhaps just under a billion years. So probably only evidence of primitive life will eventually be found ……but hey, life is life and, when we do find it, it will change our perception of the Universe and our place in it like nothing before.

  • cynic

    Looking at some of the debates elsewhere on Slugger and the cultural importance of this one (which attracts 2 posts) why do the lyrics of the Galaxy Song from Monty Python’s Meaning of Life seem so appropriate?


    Just remember that you’re standing on a planet that’s evolving
    And revolving at nine hundred miles an hour,
    That’s orbiting at nineteen miles a second, so it’s reckoned,
    A sun that is the source of all our power.
    The sun and you and me and all the stars that we can see
    Are moving at a million miles a day
    In an outer spiral arm, at forty thousand miles an hour,
    Of the galaxy we call the ‘Milky Way’.

    Our galaxy itself contains a hundred billion stars.
    It’s a hundred thousand light years side to side.
    It bulges in the middle, sixteen thousand light years thick,
    But out by us, it’s just three thousand light years wide.
    We’re thirty thousand light years from galactic central point.
    We go ’round every two hundred million years,
    And our galaxy is only one of millions of billions
    In this amazing and expanding universe.

    The universe itself keeps on expanding and expanding
    In all of the directions it can whizz
    As fast as it can go, at the speed of light, you know,
    Twelve million miles a minute, and that’s the fastest speed there is.
    So remember, when you’re feeling very small and insecure,
    How amazingly unlikely is your birth,
    And pray that there’s intelligent life somewhere up in space,
    ‘Cause there’s bugger all down here on Earth.

  • cynic

    Whoops…forgot this

  • Greenflag

    cynic ,

    ‘life is life and, when we do find it, it will change our perception of the Universe and our place in it like nothing before.’

    This depend’s on the life if any found. Let’s say some form of microbial life is found on Mars that bears a strong similarity to earthly microbial life then we can ‘assume ‘ (dangerous word 🙂 that Earth may have been ‘seeded’ from Mars .

    But if that life is totally ‘alien’ to anything found on Earth now that would be something and we might want to be careful about bringing it back here for further ‘study’ :).

    ‘And pray that there’s intelligent life somewhere up in space,
    ‘Cause there’s bugger all down here on Earth. ‘

    Reminds me of the joke during the Reagan star wars epoch of the two aliens in a far off system who discover that the planet they have been observing for a thousand years has just launched satellites into space and that said satellite now were equipped with laser weapons systems .

    Alien 1 to Alien 2 ,

    ‘Do you think this is evidence of ‘intelligent life ‘ on the planet’

    Alien 2 < 'No' Alien 1 , 'Why not ?' Alien 2' 'Their laser weapons are aimed at each other '

  • cynic

    I think it will be hard to prove the seeding theory anyway and then which planet seeded which or were both seeded by the one passing comet?

    For me, the real issue is that there’s a little equation


    that is used to predict the probability of life elsewhere and that result depends on certain assumptions.

    The probability of life developing in any given solar system was always estimated at around 1 ie that if there was a habitable planet life would evolve but its commonly then estimated the the liklihod of intelligent life is less than 1/100th of that. If extinct life were found on Mars then that might force a reappraisal.

    But above all will be the culture shock of finding that we are not alone in the Universe and that life may well be – well, universal. Now we are still a long way off that but it could all change very quickly. What a smack that might be to the ego of homo sapiens but perhaps what a spur to realising that we are all in this together and it’s a big hard universe out there.

    Yes, I know, I am a closet idealist! Dangerous around here.

  • The Raven

    Anybody in the know here point an amateur to a link about how the rivers may have stopped flowing? Or an otherwise good background article?

  • Pete Baker


    The [short] answer is gravity.

    “The answer is the gravity. Unlike its big brother Earth, little Mars could simply not hold on to its thicker atmosphere. The air slowly escaped into space, and reduced the pressure in the atmosphere over billions of years until water could no longer be a liquid. Liquids require air pressure, which is why things boil more easily at high altitudes. With less air pushing down, there is less reason for a liquid to stick together and it becomes easier to turn it into gas. This is just what happened on Mars. With the falling air pressure, more and more water became vapor.

    The absence of air also cooled Mars, because a blanket of air allows a planet to store up the heat of the Sun. As Mars cooled, water froze into the soil and the ice caps, leaving the Martian surface (and any possible life forms) high and dry.

    The longer answer probably involves the low level of geological activity and the absence of a magnetic field.

  • Pete Baker

    Bumped to answer Raven’s question.