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Earth Could Spread Life Across The Milky Way

Panspermia Illustration Courtesy of Wikipedia

Most of us are familiar with the concept of panspermia – where living organisms can be “seeded” from comet or asteroid impacts – but where does the life-giving content come from? According to a research group led by Mauricio Reyes-Ruiz from the National Autonomous University of Mexico, it just might come from Earth.

Inspired by the discovery of Moon and Mars rocks found on Earth from meteor strikes, the team began computer modeling of what might happen if pieces of Earth were transported across the Solar System via a collision scenario. The simulation involved 10,000 Earth particles moving over a period of 30,000 years. The amount of matter is tiny compared to the bulk our planet and it’s a blink of the eye in cosmic time, but scientists theorize that extreme lifeforms might be able to exist that long in space.

“The collision probability is greater than previously reported,” said Reyes-Ruiz. “It has been suggested that the ejection to interplanetary space of terrestrial crustal material, accelerated in a large impact, may result in the interchange of biological material between Earth and other Solar System bodies”

Could pieces of Earth really reach other planets? According to older theories, chances were good that some might reach the Moon or Venus, but gravity from the Sun and Earth makes reaching Mars improbable. However, the new simulations show a Mars impact – and even Jupiter – to be probable with the right ejection speeds. By involving slightly more particles at five times the rate of motion, the new results show the particles could even go beyond the Solar System. Oddly enough, the faster they moved, the lesser their chances of encountering the Moon and Venus became. Of the 10,242 tested, 691 particles ‘escaped’ out of the Solar System entirely, and six landed on Jupiter itself. Is this a Neil Young vision of flying Mother Nature’s silver seed to a new home?

Chris Shepherd of the Institute of Physics in London, who was not involved in the study, might agree with this conclusion. “This is an intriguing piece of work. The team have mapped out a really interesting scenario,” he said. One possible collision zone is Europa, the moon of Jupiter, and while the team did not simulate the number of particles that would specifically land there, many astronomers believe that it contains a large ocean, and could therefore support life.”

Original Story Source: Cosmos Magazine News Release. For Further Study: Dynamics of escaping Earth ejecta and their collision probability with different Solar System bodies.

About 

Tammy is a professional astronomy author, President Emeritus of Warren Rupp Observatory and retired Astronomical League Executive Secretary. She’s received a vast number of astronomy achievement and observing awards, including the Great Lakes Astronomy Achievement Award, RG Wright Service Award and the first woman astronomer to achieve Comet Hunter's Gold Status.

Comments on this entry are closed.

  • Lord Haw-Haw. September 1, 2011, 5:14 PM

    Thank you for the above links Tammy, both were very helpful.

  • Anonymous September 1, 2011, 5:53 PM

    very interesting. i wonder if the basic building blocks of life lead to similar looking biological lifeforms in other star systems, regardless of pansperming from Earth. a head, spine, arms and legs are so common and basic in concept for movement, and plentiful in endless variations on just our own planet. it seems less far fetched to me for there to be human-looking creatures elsewhere. not that we’ll ever find them at this distance. which is best b/c we’d probably decide we have to kill them.

  • Anonymous September 1, 2011, 6:10 PM

    I don’t think Earth can be the only place in the universe where life got going. That is almost a sort of geocentrism.

    LC

  • Mika Viljakainen September 1, 2011, 6:43 PM

    That piece of paper written by NASA intern or some such and his friends about impeding alien assault by adopting liberal views on the anthropic climate change right here on the Earth might have a point after all. Although the aliens would not make a difference between Al Gore or George W. Bush, if they fear earthly biomass being a source of contamination in the Galactic proportions.

  • Torbjörn Larsson September 1, 2011, 7:35 PM

    Actually, deep frozen remains from early Earth could be traveling towards other _galaxies_ by now, if you use the model and look for dispersal radius.

    But it isn’t terribly exciting for transpermia, since any habitable body would also have spots where life could arise. And we know from trace fossils that it likely happened early and easily here, so it should be so elsewhere. Hence indigenous life will in most cases be present, and as they are adapted to the environment out-compete and use exogenous biomatter as food.

    I’ve said it before here, but the real promise is of a historical geological (and possibly biological) record or early Earth, that plate tectonics destroyed here. Especially in the dark craters of Moon, unique and valuable material may still be present. Having it elsewhere ups the chances of finding some, especially since the Moon likely lack the convenient conveyor belt of our own Antarctica glaciers that collects and concentrate meteorites.

    • Anonymous September 2, 2011, 12:40 PM

      I doubt panspermia is intergalactic. Asteroid impacts on the Earth’s surface have a velocity range of 12 to 72km/sec. This estimate is due to impacts of parabolic trajectories with a velocity in heliocentric coordinates v = sqrt{2)v_earth, for v_earth ~ 30km/sec. So a body moving in the same orbital direction as earth has v = 42 in heliocentric coordinates or v = 12km/sec relative to Earth. Counter moving asteroids will have v_earth + sqrt{2}v_earth = 72km/sec relative to Earth. Counter rotating asteroids are rather exceptional. Fragments from impacts might escape with several times that velocity. So about the fastest a fragment might escape Earth is maybe 200km/sec. The Earth moves around the Milky Way at around 300km/sec. So this object might get knocked out of the Milky Way faster than escape velocity and reach v ~ 100km/sec far out. Assume on average the nearest galaxy is 10^6 ly away. This fragment would take around a billion years to reach that galaxy.

      The probabilities for intergalactic panspermia tend to become whittled down to very small numbers. Few fragments will ever have this large velocity, it has to be aimed right, and when it reaches another galaxy it has to reach the right planet.

      The pansperia concept as pointed out does not solve much. Ultimately there has to be some processes whereby life was generated. In keeping with scientific thought it is not likely to be a complete one time fluke. Biology might be comparatively rare, but it seems unlikely it is a one time shot in the entire universe.

      LC

      • Torbjörn Larsson September 4, 2011, 2:50 PM

        It was more of a jest, to place the idea on a scale of futility.

        But thanks for walking through the possibility!

      • Torbjörn Larsson September 4, 2011, 2:50 PM

        It was more of a jest, to place the idea on a scale of futility.

        But thanks for walking through the possibility!

  • William Sparrow September 1, 2011, 11:13 PM

    It seems unlikely that any of these particles would have landed on Europa, although it would be remarkable if any did.

  • HeadAroundU September 2, 2011, 12:13 AM

    I don’t like Panspermia. Let’s not spread these overly religious corporate theories.

    • Anonymous September 2, 2011, 2:56 AM

      In what way is panspermia religious or corporate? It simply says that microbes may be able to hitch a ride on debris ejected from planetary bodies, and that these may have a non-zero chance of surviving the trip. This is a perfectly valid and testable scientific theory, and it makes no comment on the viability or potential of abiogenesis, evolution or anything of the sort.

      As Feynman said – ‘We are trying to prove ourselves wrong as quickly as possible, because only in that way can we find progress’. We need to investigate whether or not panspermia could work in a scientific way. Not investigating this possibility, either because it doesn’t seem likely or may be hijacked by unscrupulous groups with an agenda, is about as unscientific a thing as one could possibly do.

      • HeadAroundU September 7, 2011, 2:52 AM

        ‘We are trying to prove ourselves wrong as quickly as possible’

        Don’t tell me you like this. It’s backwards. Their beliefs are completely blind which is a poor estimation of reality. I mean they don’t believe in their own beliefs. It’s ridiculous. :D

        Do I have to remind you of their “bacteria” in rocks and then selling books.

        If you pour money anywhere something will come out of it, but let’s do it seriously. They are building on rotten foundations. Don’t try to make it look as if they don’t have a bad name.

  • Anonymous September 2, 2011, 10:41 AM

    Most of us are familiar with the concept of panspermia – where living organisms can be “seeded” from comet or asteroid impacts – but where does the life-giving content come from? According to a research group led by Mauricio Reyes-Ruiz from the National Autonomous University of Mexico, it just might come from Earth.

    Sounds like circular reasoning to me and/or the question is never answered.

  • Anonymous September 2, 2011, 10:41 AM

    Most of us are familiar with the concept of panspermia – where living organisms can be “seeded” from comet or asteroid impacts – but where does the life-giving content come from? According to a research group led by Mauricio Reyes-Ruiz from the National Autonomous University of Mexico, it just might come from Earth.

    Sounds like circular reasoning to me and/or the question is never answered.

    • Torbjörn Larsson September 2, 2011, 1:11 PM

      I can’t add crucial content to what Astrofiend said so well in reply to HeadAroundU: these processes, if they happen, does not need to answer abiogenesis, but makes other predictions (spread of trace fossils and more) as well.

      I can add what I said in my own previous comment, if abiogenesis is simple, transpermia would add little biosphere volume to a galaxy as most habitable environments would already be inhabited. One would expect a margin between conditions for abiogenesis, that likely need to be more energetic and provide less harsher conditions, and biosphere potential where hardy, long evolved, extremophiles can make a living. But that margin would provide lesser volumes for transpermia opportunities.

    • William Sparrow September 2, 2011, 11:12 PM

      Living organisms can be seeded all we like, but unless the proper conditions exist where they land we can’t expect much more than single celled bacteria to survive and evolve beyond this state.

  • Anonymous September 3, 2011, 8:02 AM

    this is possible in the distant future maybe

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