If There’s Life on Mars, We Might Not Recognize It

By Nathaniel Scharping | May 20, 2016 3:09 pm

Image of Mars from the Viking 2 lander. (Credit: NASA)

The search for extraterrestrial life has expanded far beyond the bounds of the solar system and to the hordes of exoplanets circling foreign stars, but the search is far from over on the planet next door to us.

Mars beckons as a potential source of life not only because it is nearby and easy to study, but also because of evidence that water once, and perhaps still, flowed across its surface. In addition, organic compounds, although likely not of biological origin, have been discovered in the soil on Mars, which means the building blocks for life could already be there.

We Might Not Even Recognize Martian Life

Still, the mere presence of organic material is a far cry from biological life. And, if life does exist on Mars, it would have to deal with conditions far more extreme than almost anywhere on Earth, meaning that what might be sufficient for life here wouldn’t fly on the Red Planet. Life on Mars might look so different that we wouldn’t even recognize it. If life on Mars was the result of a “second genesis,” that is, it began completely separate from life on Earth, it might use combinations of organic chemicals we’ve never seen before, and wouldn’t know to look for.

Indeed, we may have actually discovered life on Mars decades ago. When the Viking landers arrived in 1976, they carried out a series of experiments to test for life, all of which came up negative. But were we performing the right experiments?

Joop Houtkooper, of the University of Giessen, thinks we may have unwittingly destroyed the life we were trying to find. He hypothesizes that potential lifeforms on Mars could deal with the extreme cold by incorporating hydrogen peroxide into their biology — by mixing it with water, they would avoid freezing and be able to survive on Mars. Hydrogen peroxide is anathema to life on Earth — that’s what makes it a useful disinfectant — and may be why researchers never thought to search for it.

Brief Hope for Life


A cutaway visualization of the azotosome theorized by Cornell researchers. (Credit: James Stevenson/Cornell)

During one of the Viking lander’s experiments, it briefly detected a weak positive signal, which then disappeared. Houtkooper thinks that this blip was the result of researchers adding water to their experiment, a step that would have killed any hydrogen peroxide-based lifeforms. Testing for specialized lifeforms such as those hypothesized by Houtkooper would require a specialized experiment, as well as another rover trip to Mars.

Such a trip is probably not going to happen any time soon. Houtkouper’s theory has been criticized by other scientists, and no hard evidence of hydrogen peroxide bacteria has emerged. But Houtkooper’s theory hints at an important consideration when searching for life beyond Earth: We shouldn’t base our assumptions about extraterrestrial life on what we observe on Earth.

The concept of expanding our search for life beyond the rules of Earth’s biology is gaining traction. Last year, a team of Cornell researchers created a hypothetical virus-like organism they called an azotosome, which they said could live in the methane seas of Saturn’s moon Titan. Using compounds derived from methane, the researchers described a way to create a liposome — a barrier surrounding cells that’s necessary for their survival — that could lead to biological life well-adapted for Titan’s  minus 290 degrees Fahrenheit climate. While their azotosome is purely theoretical, the chemistry holds up, they say, meaning there’s a chance it could exist.

While hydrogen peroxide bacteria and azotosomes are just theories, they both hint at an important consideration for astrobiology: Life beyond Earth may look wildly different on the Red Planet, and we might not even know what we’re looking for. By dreaming of biological organisms that break all of the rules of life on Earth, we may bring ourselves a step closer to actually finding them elsewhere.


This story is part of an ongoing series about Mars this summer in partnership with Astronomy magazine. See more Martian stories by visiting our Summer of Mars hub page. 

CATEGORIZED UNDER: Space & Physics, top posts
  • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

    “use combinations of organic chemicals we’ve never seen before, and wouldn’t know to look for.” Blow assorted ooze through a mass spec w/wo MALDI. One does not “look” for biochemistry. One looks for organics since inorganics lack the thermodynamic plasticity to be interesting life frameworks. If a small circuit board sneaks up and stings you, I’ll recant. “live in the methane seas of Saturn’s moon Titan” Given local temperature around -180 °C/1.4 atm, whatever it is doing it is not being rapid about it. Methane freezes at -182 °C. “at 90.6 K [-188 °C] solid methane behaves as extremely viscous non-Newtonian liquid” doi:10.1016/j.cryogenics.2012.02.001

    • Janice1425


    • OWilson

      The problem now is how are these apparently low grade beings ever going to impart their superior alien knowledge to us, and prevent us from blowing ourselves up, along with the rest of the universe.

      I’m sure they possess the higher technology to shrink us to their molecular dimensions, and school us on how to take care of the planet, before reconstituting us back to human form :)

      • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

        Get jiggy with observed Martian terrestrial biochemistry when the Vatican tap dances faster than Michael Flatley. If non-terrestrial, Youtube v=WO-rez0IhKA Board every proselytzer on a NASA colonization ship to Mars (re Pennsylvania; but not including telephone handset sanitizers re Golgafrincham and the B-Ark).

  • Steve Davenport

    Curiosity drilled into a specimen, destroying it.

    • Zemyla Cenh

      Was that specimen a cat?

      • Steve Davenport

        You must not like cats, huh?

  • richlite

    Show me a “hydrogen peroxide-based lifeform” here on Earth and this article has credence. Have we not studied this possibility already? The author even admits that “hydrogen peroxide bacteria and azotosomes are just theories.” I am ok with theories but we can’t even get people here in the scientific community to agree that a baby in the womb is a human life worthy of protection! Oh, but we must “be careful not to step on a hydrogen peroxide-based life form!” LOL !

    • Frank

      The whole point of this article is we must expand our search for life on Mars and elsewhere to include lifeforms that do not exist on Earth. Skepticism is good in science but it should be open minded skepticism. We should not jump to conclusions, but if we are not open to new ideas we impede our ability to learn new things.

      • OWilson

        They’ve been spending billions since 1970 on this search.

        It was over in 1971.

        There’s no life there!

        (Follow the money)

        • Frank

          How can you be so sure?

          • OWilson

            Well, in 45 years, our greatest technology and billions of dollars, and tests that biologists previously agreed on what constitutes life, has all failed to find it.

            We use the same logic to dismiss God! :)

          • Frank

            LOL! Good one. But remember, we haven’t looked deep underground. Certainly on the surface it’s unlikely. And as this article points out, we may have to look for life in a different form than we are used to seeing. Should we continue to pour money into this project when there are so many problems facing us here on Earth, just to satisfy our curiosity? That’s a good question.

          • OWilson

            When your National Debt is spiraling out of control, you need priorities.

            One day when planet hopping becomes routine, you’ll be able to set up your labs, do some deep drilling, and prove once and for all there’s no life there.

    • Theresa

      Well put, sir!!

    • OWilson

      We actually protect frog spawn better than children in the womb.

      Something to do with left wing self loathing.

  • Captain Obvious

    Given the vastness of the universe, if such life forms could exist, then they do exist.

    • Deuce_2112

      your hypothesis requires proof, not platitudes.

  • Stevek

    “While hydrogen peroxide bacteria and azotosomes are just theories,” ???
    A science website should be more careful with its terminology. “It’s just a theory” comes from the mouths of creationists.
    Peroxide bacteria and azotosomes are probably best described as hypothesized organisms.
    General relativity is a theory. Evolution is a theory. They are theories because they have a preponderance of evidence to support them. There is no evidence, so far, for the existence of these Martian critters. Their existence has been hypothesized.

  • Michael Skok

    We want to make life so simple that it’s a mere common occurrence. The truth is that there wouldn’t even be life on Earth because water and oxygen break down the basic building blocks of life; they do not build up. It takes a Supreme Intelligence to create life.

    • bubbles3660

      Ah yes. The old “…therefore Jesus!” argument.

    • Theresa

      Well said!How else to explain the complex life forms on earth! Even a single cell is logically constructed & can be mapped into its functioning parts!! Pretty hard to find life outside earth!!! It’s obviously “intelligently designed”! But some don’t have the guts to admit it!!

      • rukovich

        I can’t figure out why God didn’t just “bump off” Adam and Eve and start over. Keep trying till He got it right. Perhaps provide them with more information. He didn’t have any trouble slaughtering hundreds of thousands later on when they didn’t follow His instructions. Just sayin.

        • Frank

          At the risk of bringing the wrath of some of the writers on this forum down upon me, I suggest we interpret these stories subjectively, philosophically, psychologically, looking for a message that will help us live our lives better today, rather than a literal, objective historical narrative. I’m not saying I’m qualified to do this interpretation, I’m a seeker not a teacher. As you put it, “just sayin”. Have a nice day.

      • Frank

        To me, intelligent design is just that, a design. Nature moves according to this design. So if the conditions are right, nature should follow this design and life should form. From this viewpoint, this article asks us to consider the possibility that nature may be designed to produce a lifeform we are not familiar with; one very different from the types we see on Earth. Scientists recognize at least part of this design when they speak of the “laws of physics”. I am not a very religious person, but I have always found it difficult to believe there could be “laws” without some kind of intelligence behind them. And you are correct when you point out even the most “simple” form of life is extremely complex. Thank you for reading my viewpoint, have a wonderful day. Love from Frank in PA.

    • JAFischer

      Then God is a bad designer, given all the flaws in the life-forms of Earth.

      • Michael Skok

        It is because of Adam’s sin that we see all the flaws in the life-forms of Earth.

        • Frank

          Do you believe Adam’s sin was that he “ate the fruit of the tree of knowledge of good and evil” or do you believe in a different interpretation/version of the story?

          • Michael Skok

            By eating the fruit of the tree of the knowledge of good and evil, he committed the sin of disobedience; and also he took what he wasn’t suppose to take–he was guilty of stealing.

          • Frank

            Thank you for sharing your belief with me. Have a great day!

        • fred

          Not the bible please. If God make Adam and Eve only, then after kane killed Able. When he left, found other people, got married, had a family. who were they? the bible does not say they were made by god, but does say you can not marry your sister, so who did Adam and Eve’s children marry and have children with.

          • Michael Skok

            They married their sisters and cousins until God told them not to after the Flood. Mankind was nearly perfect in those early days, so there were almost no flaws in their genes.

          • fred

            if yoy marry your sister, cousin, brother, you have birth defects, IE: brain, body, so we all today would be retarted with missing limbs.

          • fred

            sounds like a vengeful god to me then. get mad at everyone. kill everyone. screw with the genes to make us less perfect, and make sure we only can use 10 percent of our brain power and make sure we are hard wired to kill, rape, pillage and lets children starve. yes a good god. ha ha so out of an entire planet only a few people were good in his eyes. seems like my way or the highway. ie: my way or I will kill you all, so kiss my a** or die. yea, a good god not.

  • Gerard DiLeo

    Hold everything! What do the celebrities think?

  • profchuck

    Some years back while working as an astronomer I was occasionally asked, “We know how to look for life as we know it but how do we look for life as we don’t know it?”

    Conjecture is about the only tool at our disposal but considering the nearly infinite number of possible chemical combinations of the elements survivable configuration are likely under even the most hostile conditions. Silicon is chemically similar to carbon so silicon based life forms, a favorite of science fiction writers, are not out of the question. It may be that the primary requirements for life are a rich collection of available of chemical elements, a large theater of operation, and a source of energy. If this is the case then even the most hostile (to us) of environments could prove to be a fertile ground for complex “life” forms. We may need to refine our definition of life however.

  • Albert Koochooei

    This a new look at sky. That probably is true. Our Assyrian ancestors have many ideas about life in other parts of sky that is mentioned in our epics. At Gilgamesh epic specially is mentioned about many parts of sky specially in underground world at beneth of sea. Special creatures we do not know about. That is what today researchs say about those wonderful creachers. Thus our ancestors Assyrians knew abouut them. With this look read Gilgamesh epuc and other epics like Enumaelish and creation.
    Albert Koochooei

  • Deuce_2112

    Hydrogen peroxide and water have approximately the same freezethaw point, within 1 C. If the biochemistry of Earth won’t support H3O based life, neither will the biochemistry of Mars. Occam’s razor, people.

  • kaflatoon

    What if there are intelligent gaseous clouds out there?


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