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Life on Mars? Why Not?

Guillaume Filion writes "IEEE spectrum has an interesting article about a new probe sent to Mars searching for life: 'Recent missions to Mars have focused on the search for water, past or present, as a surrogate for life itself. But now a British-led team is working to renew the search for life directly, fueled by doubts about the equipment that prompted NASA to declare Mars a dead world some 26 years ago.'"

11 of 227 comments (clear)

  1. why water? by SHEENmaster · · Score: 5, Interesting

    Why do we assume that life on other worlds would have the same requirements as life on earth?

    We were either created for this world or evolved into what we are by it. Doesn't it make sense that life on other worlds would be fit for theirs in the same way?

    Why is water so damn important? Couldn't life be based upon a different liquid than water? A different solid than carbon?

    --
    You can't judge a book by the way it wears its hair.
    1. Re:why water? by FortKnox · · Score: 5, Insightful

      Now, IANA Astronomer/physicist/biologist (I'm just an engineer), but here's my input.
      What you said is ENTIRELY true. We have no clue as to how other types of life can be formed. However, we DO know that water CAN cause life (worked for us, right?), so that's the 'first step' to finding life. Find stuff that formed like we did. Once we rule that out, we go into the void known as theoretical life, and try to piece something together.

      Its easier to prove something exists when you have a good understanding of it before looking at something that could be 'anything'.

      --
      Good quote, too many chars. Seriously, the slashdot 120 char limit sucks!
    2. Re:why water? by binaryDigit · · Score: 5, Funny

      Couldn't life be based upon a different liquid than water?

      beer

      A different solid than carbon?

      pizza

    3. Re:why water? by Anonymous Coward · · Score: 5, Interesting

      I can't answer the "why water" question but I do know that Carbon is the only reasonable element for basing any kind of sufficiently complex molecules needed by living organisms.

      Of all the hundreds of elements that exist in the universe, only the Carbon atom is capable of connecting to (up to four) other Carbon atoms and thus creating arbitraily large molecules. For example, a strand of DNA is single Carbon based molecule about 2 meters long. I like to think of Carbon molecules as the Lego of the universe. It's why the profession of chemistry has been divided into organic (the study of Carbon based molecules) and non-organic (the study of molecules containing every other element but no Carbon). For the record, the organic chemists have many, many times more molecules to play with than all of the molecules non-organic chemists have to play with.

  2. Airborne by SUB7IME · · Score: 5, Interesting

    If life had existed in the presumable oceans on Mars back in the day, then it is possible that there is life in the water vapor in the atmosphere (just as there is life in our atmosphere). Of course, I'm not sure that there is much (any?) water in the atmosphere on Mars. Furthermore, Mars didn't overheat, and there is not as much water in the polar ice caps as we had expected. To me this indicated that most of the water must have gone down below the surface; it could have easily brought microbial life down with it, as Earth has much microbial life beneath the earth.

  3. In a fascinating new development... by Lazarus_Bitmap · · Score: 5, Funny
    The researchers discovered Saddam Hussein, Bin Laden, and a huge cache of Iraqi WMD hiding in a crater that bore a curious resemblance to the face of Jenna Bush.

    --
    -Laz .:change is inevitable -- growth is optional:.
  4. Do we always have to scream "FIRST!"? by OwnerOfWhinyCat · · Score: 5, Insightful

    First off, the article is worth the read. They are going to do a pile of cool things, and with the PAW robotic arm, they'll be very adaptive based on what they discover. Tres' cool.

    But I must object to the following:

    Clearly, if the British lander does find life on Mars, a scientific symposium will have to be convened to sort out who may have discovered it first: NASA or ESA.

    Must we? Could we for once view science as the continuous stretch of micro-advances that it really is? Whether it's flight, or the TV, or beer the credit for doing it "first" seems to overwelm the real credit that I will lavish on the Brits at the end of the mission, and that is: the credit for doing it well.

  5. Why not? by L.+VeGas · · Score: 5, Funny

    WHY NOT?!!!!

    Because it would shake our religious and moral philosphies to their very core! Because, everything we believe in would be proven wrong!! What's wrong with you? Lord, man, I'm shaking just thinking about it.

    Oh, I thought you said wifes in bars.
    never mind

  6. Highly Unlikely by vandan · · Score: 5, Informative

    I read a book by Stuart Kauffman (hope I spelt that right). He said he was asked by NASA to help design probes to send to Mars to look for life. He told them not to bother, and his reasoning was:

    All life takes in energy and matter from the environment, extracts energy, and produces waste. This process causes chemical imbalences in the atmosphere. Therefore to test for the presence of life, you only need to determine whether the atmosphere is in chemical equilibrium. Mars' atmosphere is, and has been for many millions of years.

    Apparently this line of reasoning upset NASA, because they wanted to go to Mars, so they made their probes without his help, and when they arrived on Mars, found no traces of current life.

    If they send more probes, they could very well find evidence of past life, but there is nothing going on there at the moment.

    However I remember reading a story a while ago on Slashdot about how the atmosphere of Venus is operating far from chemical equilibrium, and that there may be some primitive life in the 400 degree acid in the atmosphere. Maybe someone should pay more attention to Venus...

  7. Why water is nifty by pclminion · · Score: 5, Informative
    Why is water so damn important? Couldn't life be based upon a different liquid than water? A different solid than carbon?

    • Water is highly polar, and therefore has the ability to dissolve ions. Without ions, complex chemistry could not take place.
    • Water is liquid at a "reasonable" temperature, meaning water in liquid form is not hot enough to destroy most complex molecules.
    • The density of ice is slightly less than that of water, so ice floats on top of water. This is vital, because it allows bodies of water to form a frozen cover which protects against further freezing. This is not common among substances.
    • Water blocks ultraviolet light, which would otherwise destroy fragile molecules and organisms.
    • Water has a very high specific heat, making it ideal for carrying out chemical reactions -- exothermic reactions can dump their heat into the water, and endothermic reactions can draw their heat from the water. This allows energetic reactions to occur without raising the temperature too high.
    Basically, water is a very unusual substance with many favorable properties, and it's likely that life will take advantage of water, if it is present.

    That's not to say that life cannot exist without water, but it certainly makes life much more plausible.

    As for non-carbon-based lifeforms, people have been pondering that for decades. Carbon is interesting because it can bond with itself pretty much ad infinitum, forming complicated structures. It also combines readily with oxygen, nitrogen, hydrogen, sulfur, the halogens, and a host of other elements. Complex life based on some non-carbon element would have to have the ability to form long chains of atoms, branching structures, and structured which curl up into specific shapes (i.e. proteins and enzymes). A carbon-silicon combo might work.

  8. Re:Oh Brother by Davak · · Score: 5, Informative
    Yes. MIR was infected with mold. This mold came from the us, the good ole earth. The interesting thing is that it mutated while in space... evolution in action.

    How about a BBC article

    The fungi that did the damage, Novikova said, included members of the genera Aspergillus, Penicillium, and Cladesporium - all very common on Earth.

    Davak