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Space Earth Moon

Planet Crash That Made Moon Left Key Elements For Life On Earth, Scientists Say 119

Scientists are claiming the cosmic collision that made the moon left a host of elements behind on Earth that were crucial for life to emerge. The Guardian reports: The impact 4.4 billion years ago is thought to have occurred when an itinerant planet the size of Mars slammed into the fledgling Earth, scattering a shower of rocks into space. The debris later coalesced into the moon. Beyond an act that shaped the sky, the smash-up transferred essential elements to the Earth's surface, meaning that most of the carbon and nitrogen that makes up our bodies probably came from the passing planet, the researchers believe.

Petrologists at Rice University in Texas reached their conclusions after running experiments on geochemical reactions under the high temperatures and pressures found deep inside a planet. They wanted to understand whether Earth acquired key elements from meteorites that slammed into Earth or through some other ancient route. Lead author Damanveer Grewal found that a planet with a sulphur-rich core would have large fractions of carbon and nitrogen on its surface. Such a planet could transfer that volatile material to Earth in just the right proportions if it happened to clatter into it, the researchers found, after modeling a billion different cosmic scenarios in a computer and comparing them to conditions seen in the solar system today.
The research is published in Science Advances.
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Planet Crash That Made Moon Left Key Elements For Life On Earth, Scientists Say

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  • The Great Filter (Score:4, Insightful)

    by war4peace ( 1628283 ) on Friday January 25, 2019 @02:03AM (#58019224)

    Maybe that was it.

    • by HiThere ( 15173 )

      Maybe. OTOH, arms races seem an awfully good candidate. (Not that the "great filter" has to be one particular thing...it could be a combination that reduces the likelihood of survival. In which case one should also include pollution and resource depletion.)

  • by Ungrounded Lightning ( 62228 ) on Friday January 25, 2019 @02:05AM (#58019228) Journal

    If such collisions are rare, a possible explanation for the Fermi paradox is that life is so rare that we may be the firsrt.

    No need for things like intelligence almost always self-destroys, etc.

    • Indeed. Probably reduces the likelihood by a couple of orders of magnitude.

    • by evanh ( 627108 )

      The researchers of the published "research" are starting from the position that Earth is the only life-bearing planet in existence. And appear to assume that to be the only option!

      That's just dumb.

      • I was more of wondering what made them come up with the hypothesis to test. Was there something they found or saw in other research... or was it just: "Hey I bet this could work, let's run some models on the computer!" Just out of curiosity of the origin of their tests.
        • by evanh ( 627108 )

          The original paper opens with this: "Earth's status as the only life-sustaining planet ..."

          And then never strays from that as the only option. It's an obvious dumb assumption that projects into the conclusion.

    • by Dutch Gun ( 899105 ) on Friday January 25, 2019 @06:09AM (#58019720)

      What do you think the more likely explanation is:

      a) that among the estimated billions of Earth-sized planets in our galaxy, plus those among the other ten trillion galaxies, we're some rare and special one-off jewel of the universe,
      b) universal distances are vast, and warp drives aren't practical or even possible. As such, other intelligent aliens can't reach us, or even communicate with us.

      Personally, I tend to view the "mediocrity principle" as more reasonable than "special snowflake" assumptions, and simply attribute the lack of evidence about alien life as corroboration of the difficulty in overcoming interstellar distances in any meaningful way.

      • You're forgetting about the anthropic principle... the fact is that we are here to watch and inquire, and there are so many other stages of evolution and civilization, it doesn't make sense that all possible life should evolve to a very high stage of development. It takes a special one to even ask themselves about alien life.

        • it doesn't make sense that all possible life should evolve to a very high stage of development. It takes a special one to even ask themselves about alien life.

          Intelligence is useful in all environments, which is why it's reasonable to assume that it would arise anywhere it was possible, eventually.

          • by dryeo ( 100693 )

            It's not just intelligence. We have multiple examples of intelligence on our Earth at our time.
            Has to be general purpose, as in not stuck in a small habitat.
            Has to be in an environment that allows technology, hard to do under water for example.
            Needs the means to manipulate its environment, something like hands along with the coordination to use them.
            Needs the means to pass on knowledge. An octopus for example starts each generation with zero knowledge as they don't have families. They also have relatively s

            • Then they have to have the drive to make the jump to high technology.

              To be honest, I think what they need is command of fire. Without being able to use fire, you can't make advanced tools, or really anything of permanence. Some of the other primates are starting to figure it out, but almost no other animals use fire, and those that do generally only use it in one limited way. Maybe that's how we got so naked.

              • by dryeo ( 100693 )

                Yes, fire is perhaps the biggest step. Still it seems it is a step that was taken perhaps more then a million years ago and pretty surely 120,000+ years ago for being able to start fires, so still a lot happened after. https://en.wikipedia.org/wiki/... [wikipedia.org] is interesting.

              • by HiThere ( 15173 )

                There's reasonable evidence that homo erectus could control fire. The main difference between Neanderthals and Cro-Magnon seems to have been that Cro-Magnon's lived in larger groups, so there were more sources to exchange ideas between

                If I had to pick one thing, I'd pick language. And the problems with the FOX P2 gene https://www.google.com/search?... [google.com] show that it is genetically mediated. (Well, of course that was obvious. But only after you notice that it's obvious. There are lots of examples of peopl

      • by bazorg ( 911295 )

        c) A sort of mixed scenario.

        Imagine a bell shaped curve for a distribution of the number of civilisations per... area. We could be in one of the star systems that has nothing around it, while there could be other star systems with 1 or more civilisations, surrounded by other such star systems.
        They are close enough to see each other, and have all sorts of Star Wars/Star Trek type of interactions, while we are here in the middle of nowhere.

      • by Tablizer ( 95088 )

        b) universal distances are vast, and warp drives aren't practical or even possible. As such, other intelligent aliens can't reach us, or even communicate with us.

        The distances are only "long" if viewed from a single human's life-span. Multi-generational being and/or robotic nuclear-powered ships can be built. We could make such now if we had enough cash and will-power.

        • by dryeo ( 100693 )

          It's hard to imagine technology that keeps working for 100's to 1000's of years and hard to imagine a group of people staying stable for 100's of years.
          Look at how civilization has changed on the Earth just over a couple of hundred years, little well 1000's.
          Longer life times might be a requirement and would definitely help. Need stability and the means to repair and maintain for a long time just to cover a few light years at a few percent of light speed. Takes a lot of energy to accelerate a substantial mas

        • by HiThere ( 15173 )

          No. The distances are long if you have a destination in mind. They aren't long if you're a space adapted civilization, that does its living in space. The question is, are there enough wandering planets/asteroids/comets/whatever-you-want-to-call-it to keep the wanderers in resources. With fusion power and slow travel speeds (just a bit above the speed of the drift) I think it's probable. It might even be possible with fission power.

          OTOH, this requires a sociology far in advance of our current level. Pr

      • b) universal distances are vast, and warp drives aren't practical or even possible. As such, other intelligent aliens can't reach us, or even communicate with us.

        They don't have to reach us to be detected. There's this thing called "radio" - kind of a low-frequency starlight - which spreads out just like it and is very easy to notice (if not always to decode correctly).

        The fermi paradox is based on the idea that intelligent life achieving technology is almost certain to develop and use radio, and that said

        • You'll notice that, though broadcast AM and FM audio are still with us (though we're starting to convert FM), the big foghorn - television - has already switched from two big carriers (one giant AM with a subcarrier on the modulation, one FM just like an FM radio station) to a digital schemes based on OFDM 8VSB, or the like. Lower power and very noise-like.

          So intelligent life might be detectable by radio, not from the rise of technology onward, but only during the century or so between the development of r

        • They don't have to reach us to be detected. There's this thing called "radio" - kind of a low-frequency starlight - which spreads out just like it and is very easy to notice (if not always to decode correctly).

          I think that they've actually figured out with data coming back from the Voyagers, that no, it's not easy to detect. Our broadcast radio and TV signals are too low power and basically hit the heliophere and become noise at any interstellar distance. Radar however seems to be a good candidate, especially at the powers and frequencies needed to do radar astronomy with it. Even the combined use of aviation radar across the globe is probably detectable at 50 ly currently with our own tech (if we'd build a detec

      • "Snowflake"??? Hey, you're going to hear from some Trump supporters here...

    • If such collisions are rare, a possible explanation for the Fermi paradox is that life is so rare that we may be the firsrt.

      Sure, because it couldn't possibly have existed on the thing that was full of life-giving chemicals that hit The Earth.

      • Sadly, I have no mod points to give you today - only this huzzah.

        Huzzah.

      • I believe the point was that the life-giving chemicals (carbon and nitrogen, among others) were also hidden in the core of that body. That body had to be shattered to get the chemicals out of that core.

        That said, I already posted above that a couple other planets and at least one large moon in our solar system have carbon (and some have nitrogen) at the surface.

    • by dryeo ( 100693 )

      Or a combination of the two. Seems a lot has to go right for complex life to evolve, took close to 4 billion years on the Earth, that means everything has to be right and stay right for a hell of a long time. Then intelligent, technological, curious life must evolve.
      Then there is the vast distances. Even if there were a 100,000 civilizations in our galaxy, that's still 1 in a million stars.

    • There are indications that several planets in our solar system suffered from similar impacts (Venus and its 116 day long 'day', Uranus and its tipped over axis) 3 out of 8 would not be a rare event
    • That was my initial thought too. However: we've now landed on several planetary bodies, including large moons (hey, no Star Wars cracks, please!): Venus, Mars, and Titan; plus several asteroids. (Earth's moon doesn't count, since it was involved in this same collision, and came out the loser.) Mars has some carbon in the form of its (thin) carbon dioxide atmosphere, but not much nitrogen afaik. Similarly Venus's thick carbon dioxide atmosphere, with a little nitrogen. Titan seems to be abundantly provi

  • So God-did-it! I mean it was aliens. Alien gods?

  • by Fly Swatter ( 30498 ) on Friday January 25, 2019 @02:16AM (#58019262) Homepage
    When they come to use their planet, we're doomed. Look what we did to it.
  • by backslashdot ( 95548 ) on Friday January 25, 2019 @02:20AM (#58019280)

    Also in that issue of Science Advances, Alzheimerâ(TM)s is caused by bacteria in your teeth. Yes, caused by. Not kidding, the bacteria releases cytotoxic vesicles that fragment the neural tau proteins.

    • by Anonymous Coward

      Also in that issue of Science Advances, Alzheimerâ(TM)s is caused by bacteria in your teeth. Yes, caused by. Not kidding, the bacteria releases cytotoxic vesicles that fragment the neural tau proteins.

      While I always enjoy reading about new breakthroughs and discoveries, this one has me rather perplexed. Dental advancements have also grown leaps and bounds in the last century. We have a greater capability to take care of our teeth today than we ever have.

      Given that fact, why do we see a massive increase in Alzheimers in the last century? If this latest theory holds true, than the number of retired dentists afflicted by Alzheimers should be zero. Chances are it's not, confirming that this disease has f

      • by Anonymous Coward

        life expectancy increases and maybe all that dental hygiene (and sugar rich diet) is disrupting the human mouth biome that would act as a line of defense?

  • by Anonymous Coward

    What kind of trajectory would lead to such a crash?

    It seems like that planet coming from the solar system itself would be unlikely, since it would have to have a vastly different speed and/or direction in any case.
    Even if they spiraled towards each other, the crash would be more or a bump than something thet can cause that much debris.
    And if it got redirected e.g. by Jupiter, it also still would have to form far enough and have a speed different enough to bring it close to Jupiter at the right time.

    I know:

    • by Anonymous Coward

      the crash would be more or a bump

      I don't think objects whose masses are in the order of 1E25 kg and which travel at velocities above 1E4 m/s can just "bump".

    • Once you believe this story, we will then issue the source of the planet (Our God sent it :p). Yeah in that planet, life was seeded by another planet colliding there.. u see turtles all the way down.
    • The solar system was full of planetesimals early in its evolution. Lots of objects orbiting and interacting with each other caused objects to have fairly chaotic orbits. Most of these things over time will collide with each other, and either breaking into bits or combining into one. The Earth was probably formed by a number of these collisions. This last object was in a similar orbit to Earth that either crossed or just came nearby. So it was moving in the same direction and similar orbital speed. Both it a
    • The current theory is that orbital resonance allowed Earth and Thea to form in similar orbits until they reached a certain mass threshold and the orbit became unstable resulting in the collision. Models show an impact speed on the order of 4km/sec which is comparatively slow (a meteor is about 10 times that).
    • "like that planet coming from the solar system itself would be unlikely, since it would have to have a vastly different speed and/or direction in any case": I would have thought so too, but look at Ultima Thule, which clearly formed from such a low speed collision. And it's way the heck out there, were the average distance between large objects must be much larger, hence--one would think--collisions would be much rarer.

  • "Earth's status as the only life-sustaining planet ..." is such an obviously flawed assumption. It's worse than saying there is nothing inside a black-hole just because the current maths breaks down.

    • Actually depending on the size of the black hole, the event horizon can be quite far away from it. I think Stanislav Lem did the math once in a story and a planet with live was just behind the edge of it.

  • There's a touch of poetry in that.

  • FWIW (Score:2, Interesting)

    by Anonymous Coward

    The Giant Impact Hypothesis became popular with the experts because it explained why the compositions of the Earth an Moon are so similar. The major problem with it (at the time) was such a collision would blast an enormous amount of the planets into an orbiting cloud of debris and a whole lot of the lighter elements and compounds (like water) would be lost to space. It's estimated that such a collision would heat Earth's surface to over 500 C, maybe over 1000C. It would "only" take 50 or 100 million years

  • Very Nice Article. Please keeping posting.
  • Meme in 3, 2, 1, ....

  • Does anyone else find it funny that scientists expect us to believe they know what happened 4.4 billion years ago when, with all their scientific academia, scientists can't reliability tell me what the weather is going to be like next weekend?
    • Said by the person posting on a device made possible by the precise predictions made by quantum mechanics over a nework reliant on a complete and full understanding of General Reletivity
  • The better title.... "Moon Crash in to Earth Allows Life", and being that I am a scientist... I also say it.

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