Earth life 'may have come from Mars'

Gale crater, Mars Life would face challenges on Mars today, but billions of years ago conditions might have been better

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Life may have started on Mars before arriving on Earth, a major scientific conference has heard.

New research supports an idea that the Red Planet was a better place to kick-start biology billions of years ago than the early Earth was.

The evidence is based on how the first molecules necessary for life were assembled.

Start Quote

The evidence seems to be building that we are actually all Martians; that life started on Mars and came to Earth on a rock”

End Quote Prof Steven Benner Westheimer Institute for Science and Technology

Details of the theory were outlined by Prof Steven Benner at the Goldschmidt Meeting in Florence, Italy.

Scientists have long wondered how atoms first came together to make up the three crucial molecular components of living organisms: RNA, DNA and proteins.

The molecules that combined to form genetic material are far more complex than the primordial "pre-biotic" soup of organic (carbon-based) chemicals thought to have existed on the Earth more than three billion years ago, and RNA (ribonucleic acid) is thought to have been the first of them to appear.

Simply adding energy such as heat or light to the more basic organic molecules in the "soup" does not generate RNA. Instead, it generates tar.

RNA needs to be coaxed into shape by "templating" atoms at the crystalline surfaces of minerals.

The minerals most effective at templating RNA would have dissolved in the oceans of the early Earth, but would have been more abundant on Mars, according to Prof Benner.

Red or dead

This could suggest that life started on the Red Planet before being transported to Earth on meteorites, argues Prof Benner, of the Westheimer Institute of Science and Technology in Gainesville, US.

Why is Mars so lifeless?

Mars taken by Mars Global Surveyor
  • No magnetic shield: Mars' magnetic field disappeared four billion years ago, allowing the solar wind to strip away the planet's atmosphere
  • The missing atmosphere: Mars has just 1% of Earth's atmospheric pressure, so heat from the Sun escapes into space, making the planet very cold
  • Too cold for liquid water: Mars sits outside the so-called Goldilocks Zone where the temperature is 'just right' for water to remain liquid - vital for life as we know it

The idea that life originated on Mars and was then transported to our planet has been mooted before. But Prof Benner's ideas add another twist to the theory of a Martian origin for the terrestrial biosphere.

Here in Florence, Prof Benner presented results that suggest minerals containing the elements boron and molybdenum are key in assembling atoms into life-forming molecules.

The researcher points out that boron minerals help carbohydrate rings to form from pre-biotic chemicals, and then molybdenum takes that intermediate molecule and rearranges it to form ribose, and hence RNA.

This raises problems for how life began on Earth, since the early Earth is thought to have been unsuitable for the formation of the necessary boron and molybdenum minerals.

It is thought that the boron minerals needed to form RNA from pre-biotic soups were not available on early Earth in sufficient quantity, and the molybdenum minerals were not available in the correct chemical form.

Shergottite meteorite from Mars Meteorites from Mars have been arriving on Earth throughout our planet's history

Prof Benner explained: "It’s only when molybdenum becomes highly oxidised that it is able to influence how early life formed.

"This form of molybdenum couldn’t have been available on Earth at the time life first began, because three billion years ago, the surface of the Earth had very little oxygen, but Mars did.

"It’s yet another piece of evidence which makes it more likely life came to Earth on a Martian meteorite, rather than starting on this planet."

Early Mars is also thought to have had a drier environment, and this is also crucial to its favourable location for life's origins.

"What’s quite clear is that boron, as an element, is quite scarce in Earth’s crust," Prof Benner told BBC News, “but Mars has been drier than Earth and more oxidising, so if Earth is not suitable for the chemistry, Mars might be.

"The evidence seems to be building that we are actually all Martians; that life started on Mars and came to Earth on a rock," he commented.

"It’s lucky that we ended up here, nevertheless - as certainly Earth has been the better of the two planets for sustaining life. If our hypothetical Martian ancestors had remained on Mars, there may not have been a story to tell."


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  • rate this

    Comment number 1220.

    @1218: I once wrote on "why we don't see signs of aliens" and did not know the name for it is the Fermi Paradox. Thanks. 718 (Ed Pick) puts your broader point too. However, I think the premise that a 2nd planet delivered viable RNA on the shards of a meteor is unprovable and less likely than RNA occurring on earth. Regardless! Consciousness is much more elusive - can we search for that too please?

  • rate this

    Comment number 1219.

    @1217 -- I admire your reason/math (and wish peeps would rate the validity of a comment for its worth rather than whether or not they agree). However, as R Dawkins suggests, evolution, not just as a theory but also as a philosophy, is the one and only *possible* logic that permits something from nothing. Without it, you can't even explain God. Oh.. was that lightening outside? Ps: @1216 - Cheers.

  • rate this

    Comment number 1218.

    This potentially goes a very long way to solving the Fermi Paradox (why we don't see signs of aliens) it seems that life on earth was an even rarer event that we expected, requiring a small water-rich (and relatively cool) planet such as mars to breed the life and then the warmer and larger earth to incubate it. This plus the leap from unicellular to multicellular life could explain much!

  • rate this

    Comment number 1217.

    The possible info contained in a single gene is huge with 4x10 to the power of 1000 possible diff forms. The calculated number of particles in the whole universe is 10x10 ttp of 80. The law of small probability is 10x10 thp of 150. Probability of DNA evolving is 1 in 10x10 to tp of 4,478,296, Thats 10 followed by over 4 million zeros. No 1 could believe DNA, exsists, except that it does. CREATION

  • rate this

    Comment number 1216.

    @1215. Faith Misplaced

    Food for thought dude


  • rate this

    Comment number 1215.

    @1210. That's an infallible truth. Cool indeed. But theorising it likely occurred that way presumes that the probability of life evolving to RNA stage on earth on its own is *less than* the probability of there happening to be a complimentary planet (Mars) that evolved RNA life and found its way to earth intact despite a very violent meteor impact. I note 718 (Ed Pick) puts my concern better. :)

  • rate this

    Comment number 1214.

    Scientific data comes, much of the time, fragmented in bits and pieces. I wouldn't go so far as to say it's "worthless" but more data is certainly needed to present a more comprehensive understanding of the possibility.

  • rate this

    Comment number 1213.

    Evolutionary science is like a drunkard who gazes long at the bottle. Then one comes up to him and asks, "What do you see?" That drunkard looks up, a swiftful smile slowly sweeping across his dazed eyes, then looks down at the nearly empty bottle. Pouting his lips, hugging it passionately to his chest, he kisses it, drawling loudly, "I love you, Ana!"

    Life flew in from Mars, my foot!

  • rate this

    Comment number 1212.

    1208. Mcd

    Another implausible and evermore desperate attempt by the scientific community to deny what is so evident – life exists on earth because God said so!
    take a minute, now pause and think past the propaganda youve been fed since you were born... and just take a second to consider the possiblity there is no imaginary sky-being... your life will be much happier after that =)

  • rate this

    Comment number 1211.

    Well done 1208 Mcd

    It must be as you say, because you are a world renowned scientist, & you have the ear of God... NOT

  • rate this

    Comment number 1210.

    @1209. Faith Misplaced
    that's cool dude :) note worthy tuppence

    but it occurs to me (and i am but shaved chimp reading the works of shakepsear) that 2 planets (or more) swapping spit as it were, might increase the available resources, by increasing the amount of environments that were available to create them.
    It is possible that might actually increase the odds
    Any thoughts ?

  • rate this

    Comment number 1209.

    @1207.. No problem. Yes, that initial chance of self replication, whether on Mars or Earth, is so low as to be preternatural, but not supernatural. It was just my tuppence that IMHO the theory is flawed (by virtue of it being less probable, and theories have to stand up to evidence including probability tests?), notwithstanding I respect it as a theory. I must say something more provocative.. :-)

  • rate this

    Comment number 1208.

    Another implausible and evermore desperate attempt by the scientific community to deny what is so evident – life exists on earth because God said so!

  • rate this

    Comment number 1207.

    but would better suit latter evolution, implies we need Two planets for life to spontaneously occur, with the chances being absurdly low. Cheers.
    OK i can see that
    But current the chances of the evolution from Chem Compound to RNA and RNA to Life is so low anyway I am not sure requiring 2 planets actually affects the odds adversly.
    I am not disputing your comment
    just curious about it

  • rate this

    Comment number 1206.

    @1205 As a fan of R Dawkins, I would advocate the first replicators would more easily evolve in the highly complex crystals that form in clay (seen only in electron microscopes). But the suggestion that early Earth wouldn't support this as well as Mars, but would better suit latter evolution, implies we need Two planets for life to spontaneously occur, with the chances being absurdly low. Cheers

  • rate this

    Comment number 1205.

    @1204. Faith Misplaced

    I am mean why is it to far fetched ?

    Also the article (research) doesn't claim Life came Mars specifically, but that:- Life or Lifes building blocks (RNA) or even RNA's building blocks (molybdenum & Boron) may have.

  • rate this

    Comment number 1204.

    Far out. Understood, but it's just too far fetched. So are we the result of some kind of inter-planetary copulation? For life we need not just one, but Two RNA bearing planets, one as a seed creche, the other to receive a 1 in a trillion chunk of rock with RNA that survived the heat & impact that blasted it off the 1st? That Would make life elsewhere Very rare. So why me, here in this meat sack?

  • rate this

    Comment number 1203.

    @1193. skemmite
    55 MINS AGO
    When will "may" be banned from professional journalism . Maybe aliens made earthlife.. Maybe this that or the other. Until its fact dont even mention. but Maybe real journalists might happen.

    But this is theory that is being reported, due to new scientific knowledge.
    There are no Absolutes
    Just new info that may nudge the debate in another direction.

  • rate this

    Comment number 1202.

    1201.Science Skeptic

    Another thing I'm not against. So long as a person's belief doesn't result in the harm of another, I couldn't care less what they believe.

    Give people the facts and all the information available and let them make their own minds up.

  • rate this

    Comment number 1201.


    "The united states would also be a good example of faith interfering. Teachers are prevented from teaching about evolution and in some cases promote teaching creationism as a Science"

    I agree that religious believes should not be taught at school to the detrement of scientific facts, but religious tolerance should.


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