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Earth Science

Earth Could Collide With Other Planets 255

Posted by CmdrTaco
from the i-like-my-crust-liquified dept.
Everybody put on your helmet; Smivs writes "Astronomers calculate there is a tiny chance that Mars or Venus could collide with Earth — though it would not happen for at least a billion years. The finding comes from simulations to show how orbits of planets might evolve billions of years into the future. But the calculated chances of such events occurring are tiny. Writing in the journal Nature, a team led by Jacques Laskar shows there is also a chance Mercury could strike Venus and merge into a larger planet. Professor Laskar of the Paris Observatory and his colleagues also report that Mars might experience a close encounter with Jupiter — whose massive gravity could hurl the Red Planet out of our Solar System."
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Earth Could Collide With Other Planets

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  • mors certa, hora incerta
  • by GreenEnvy22 (1046790) on Thursday June 11, 2009 @08:26AM (#28292415)
    There are tiny odds of just about anything happening, why is it news?
    • There are tiny odds of just about anything happening, why is it news?

      Yeah, and we can't even use the excuse that it was a posting by kdawson. Come on, Taco!

    • Re: (Score:3, Interesting)

      by Saint Stephen (19450)

      As Stephen King said, "Everything's eventual."

      Yeah, man, everything's REAL eventual :-)

      Great line - I keep telling myself that.

      • Re: (Score:3, Interesting)

        by Quothz (683368)

        As Stephen King said, "Everything's eventual."

        He did not. I'm sure he said those words at some point, but not as a statement. He entitled a story "Everything's Eventual" (hell, likely as not, his editor entitled it). Pat Conroy did not say "The lords of discipline", John Barth did not say "Lost in the funhouse", and Douglas Beane did not say "Too wong foo, thanks for everything, Julie Newmar". Yeesh! This is even worse than people who attribute characters' quotes to the author directly.

    • by Dystopian Rebel (714995) * on Thursday June 11, 2009 @08:46AM (#28292781) Journal

      There are tiny odds of just about anything happening

      I know that fervent believers will condemn my denial of the Elephant Rapture, but there is zero chance of the Earth turning into a proboscidean of any sort.

    • by Quaoar (614366)
      1% in 5 billion years is actually fairly high...you're talking some major solar system engineering if Mercury's orbit suddenly starts to look funny.
      • Re: (Score:3, Informative)

        by Quaoar (614366)
        I realize the linked article doesn't have the 1% figure, here's a better article:

        http://www.universetoday.com/2009/06/10/wild-little-mercury-to-cause-interplanetary-smashup-maybe/
    • "What was that 'one in a million' talk all about then"?

      There's a tiny chance anyone on here will ever kiss a girl, but we still sit puckered up just in case. You know we all do. Muuuuuaah.

    • by Thaelon (250687)

      Because the collision of two planets is beyond epic.

  • I can record that event in my 64bit unix timestamp field.

  • No big deal here (Score:3, Informative)

    by JoshuaZ (1134087) on Thursday June 11, 2009 @08:29AM (#28292467) Homepage
    We've known for almost a hundred years (since Poincare more or less) that the 3 body problem is inherently chaotic and not terribly stable and here we have an n body problem for large n. All they seem to have done here is list some of the more catastrophic possible outcomes if the system becomes seriously unstable.
    • by Rockoon (1252108)
      Is it actualy known that for larger n, systems are inherently less stable than when n=3?

      I'm not so sure.
      • by JoshuaZ (1134087)
        Defining what one means by more or less stable becomes difficult. I'm not an expert in this sort of thing so I don't feel confident discussing it in any detail. However, the computational difficulty in approximating what happens from as one goes from time t to t + epsilon does go up a lot when one increases the number of bodies.
    • by Quaoar (614366)
      Being able to quantify the odds is an achievement. Why belittle it? Where's your paper on the multi-billion year evolution of the solar system?
      • by JoshuaZ (1134087)
        I'm not sure from reading TFA they did do much in the way of actual quantification. There aren't any probabilities listed. There method of doing so, taking a large sample of test runs (around 2500 according to the article) and seeing how many resulted in what outcomes is not that great a way of working out the actual probabilities. It is at best, a rough order of magnitude estimate. I'm not bashing the work. As you say, I don't have any papers on the multi-billion year evolution of the solar system. But I d
    • Re:No big deal here (Score:5, Informative)

      by mrsquid0 (1335303) on Thursday June 11, 2009 @09:30AM (#28293551) Homepage

      Actually, this result is a big deal. First, the authors used powerful new techniques to solve some long-standing problems in these sorts of simulations. This has allowed them to run simulations far further into the future (or the past) than was possible before. Second, they included General Relativity and the affects of planetary satellites in their calculations, which improves the precision of their results. This has not been done before. Third, this work is the first to put a quantitative time scale on instability in the inner Solar System. Up until now we knew that the orbits of the inner planets were unstable, but we had no idea how long it would take for those instabilities to lead to major changes in orbital parameters. Finally, this result has profound implications for the stability of planetary systems in general, which affects the probability of their being Earth-like planets around other stars, and thus the chances of there being animal life out there. This is a major paper and may become the baseline for this entire sub-field. It certainly deserved to be published in Nature. It is too bad that the media chose to glom onto the sensationalist aspects of the story.

    • We've known for almost a hundred years (since Poincare more or less) that the 3 body problem is inherently chaotic and not terribly stable and here we have an n body problem for large n. All they seem to have done here is list some of the more catastrophic possible outcomes if the system becomes seriously unstable.

      What's more interesting than the odds and particular outcomes is the advances in simulation methodology which enable them to reach those conclusions.

  • by J4 (449)

    Looks like God screwed that one up.

  • by ionix5891 (1228718) on Thursday June 11, 2009 @08:33AM (#28292533)

    first they announce that the recession is over in the UK (yeh right!)

    then we find out earth is about to collide with another planet

    at least the later is more believable :D

    • first they announce that the recession is over in the UK (yeh right!)

      Actually, by one measure, it is over in Britain [slashdot.org]. Diffusion indexes show that the British economy expanded slightly recently. You Brits should probably not vote that Labor party out quite yet...

  • I begin to wonder if scientists release this stuff just to get attention, or because they're waiting to see how badly it will get reported by the media. Yesterday we had crude CGI on the BBC of the Earth and Mars bumping together in a head-on collision like a pair of billiard balls, with almost no context, and big clouds billowing out (at thousands of kilometres per second) exactly as if the Solar System had a dense atmosphere to constrain them.

    Is it any wonder the general public doesn't take science seriou

    • Is it any wonder the general public doesn't take science seriously nowadays?

      They will as soon as someone makes the movie.

    • by Nimey (114278) on Thursday June 11, 2009 @09:27AM (#28293491) Homepage Journal

      How do you know this is the fault of the scientists? It could very easily be lazy and/or sensationalistic journalism -- same stuff as "this has as much info as x libraries of congress" or "as much volume as x ping-pong balls", or half of what kdawson posts.

    • by Ironica (124657)

      Is it any wonder the general public doesn't take science seriously nowadays?

      It sort of seems like the problem is that science doesn't take the general public seriously nowadays.

  • http://www.nature.com/nature/journal/v459/n7248/full/nature08096.html [nature.com]

    Full story requires payment or subscription (which I don't have), but the blurb reads:

    It has been established that, owing to the proximity of a resonance with Jupiter, Mercury's eccentricity can be pumped to values large enough to allow collision with Venus within 5 Gyr (refs 1-3). This conclusion, however, was established either with averaged equations1, 2 that are not appropriate near the collisions or with non-relativistic models in w

  • by Junior J. Junior III (192702) on Thursday June 11, 2009 @08:44AM (#28292747) Homepage

    Let's go back to crystalline spheres and immutable heavens. That was a much safer design model

    • by Zarf (5735) on Thursday June 11, 2009 @09:03AM (#28293073) Journal

      Let's go back to crystalline spheres and immutable heavens. That was a much safer design model

      Sadly we weren't using version control back then and our backups have been lost. It looks like we can't revert to the last stable version so we will have to find a way to make the current system stable until we can upgrade to Universe 2.0.

      • we keep trying to upgrade to universe 2.0.

        the thing is, god forgot to install a watchdog timer and the system keeps booting and resetting endlessly.

        what we need is god 2.0 - to really fix this implementation correctly.

    • Let's go back to crystalline spheres and immutable heavens. That was a much safer design model.

      On the other hand, it could be worse.

      If Mercury and Venus, for example, collide and merge into one, all those born under the sign of Gemini and Libra will be doomed to live in uncharted (pun intended) territory.

  • were no longer allowed to use arcane mathematical models.

    Give a man a model, and he'll fret for a day. Teach a man to model, and he'll have major news media fretting forever...

    • Re: (Score:2, Funny)

      by Rashdot (845549)

      Give a geek a model, and he'll fret for a day. Teach a geek to model, and he'll have major news media fretting forever...

      There, fixed that for you. Because:
      Give a man a model, and he'll have a great time with her.

  • by baKanale (830108) on Thursday June 11, 2009 @08:50AM (#28292859)
    They're killing independent George!
  • Just the workarounds for the floating point math must be cool to see. Or the optimizations they would use in a simulation like this.

  • What a Swell Party This Is [lyricstime.com]

    "Have you heard that Mimsie Starr
    Just got pinched in the As...tor bar?
    Well, did you evah?
    What a swell party this is!

    Have you heard? It's in the stars,
    Next July we collide with Mars!
    Well, did you evah?
    What a swell party this is!"

  • "A couple billion years? Who cares, I'm not in office anymore when that happens!"

    • by Chrisq (894406)
      Knowing my luck I will be reincarnated as a programmer and working on the Y2M problem. And still wondering whether Cobol can last another decade.
  • We're all gonna DIE!!!

    (OK, now off to actually read the article....)

  • I have a solution. We get Martin Landau to lead us on a Moonbase that we construct. Since it is the first moonbase ever, we will call it Moonbase Alpha. We detonate a nuclear weapon on the surface of the moon, causing it to rocket away from the Solar System, like when Wile E. Coyote attaches a bottle rocket to a car.

    We launch out of the Solar System and into the galaxy, meeting strange alien beings along the way. We will build shuttlecraft, and call them "Eagles".

    Earth crashes into Mars, we move into
  • This is funny because I was thinking just the other day about the cheesy overused lyric 'when two worlds collide' - I mean, it just doesn't happen that often does it?
  • by starglider29a (719559) on Thursday June 11, 2009 @09:11AM (#28293227)
    Ok, here's a question: Has this happened in the past?

    It doesn't take long playing with simple, fun orbit simulators [arachnoid.com] to see that while most planetesimals get glommed, a few get chucked. Escape velocity from the Sun at Mars distance is WAY MORE* (technological term) than Jupiter could perturb. Some things tossed could have 'very long' periods, but still not escape. THAT would be news.

    And yes, I am a rocket scientist and yes, I HAVE done the math.

    Vcircular * sqrt(2) = Vescape! 41% is too much, even for Jupiter.
    • by powerlord (28156)

      I'd laugh if Velikovsky had some of the radical ideas right (even as he was vilified for the totality of his thoughts).

      "Worlds in Collision" indeed.

      • Re: (Score:3, Insightful)

        by starglider29a (719559)
        I wonder what Slashdot would have said about Relativity, Quantum Mechanics and the Cosmological Constant when those ideas were first burgeoning. And from a PATENT CLERK, no less.
    • The current theory is that a Mars-sized planet collided with Earth sometime in history. When this planet, usually named Theia [wikipedia.org], collided with Earth, some of the disturbed matter from both planets got ejected into space, some fell onto and became part of Earth, and some got caught in orbit around Earth as natural satellites.

      The resulting dust either escaped or eventually coalesced into the modern Earth and Moon.

  • >> Mars might experience a close encounter with Jupiter -- whose massive gravity could hurl the Red Planet out of our Solar System.

    Woo hoo! Let's colonize it now. We won't have to worry about the inter-stellar travel problem.

  • Movie Promotion? (Score:2, Interesting)

    by snooz_crash (802357)
    With the movie remake of When Worlds Collide due out in 2010, a story like this would be one way to create a buzz.
    http://www.imdb.com/title/tt0455856/ [imdb.com]
  • "But when worlds collide," said George Pal to his bride, "I'm gonna give you some Terrible Thrills."

  • They ran a numerical simulation of the solar system through more than a billion cycles of the Earth's orbit... presumably thats a trillion time steps of their simulation, at the very least (1000 steps per orbit would give poor accuracy over that many iterations), and preferably more like a quadrillion time steps. Even with that, I'm suprised anyone thinks that so few iterations can be relied upon to give meaningful results over such a long time.

    Since Nature actually published them, I wonder if perhaps th
    • It's Mercury colliding with other planets, not Earth, and I read the article on Ars Technica yesterday, and you're right, the collision isn't the focus, it's the ability to use more complex equations using variables previously ignored due to that complexity in modelling, coupled with similarity of some previous work, apparently. What's more, they ran 2500 simulations, and less than 1% had Mercury colliding with a planet.

      "Out of the 2,500 runs that were performed, only about one percent resulted in a major d

  • Astronomers calculate there is a tiny chance that Mars or Venus could collide with Earth -- though it would not happen for at least a billion years.

    That's no reason not to print another $500 billion to study the problem! If it saves just one child's life in a billion years, then it's worth it! Why do you hate the Earth? Hater.

  • Why can't they come up with a plausible theory of apocalypse by snu-snu?

  • Just blow up the sun so it stops swinging these planets at us.
  • Could they also calculate the probability of monkeys flying out of my ass? Or would this be considered racist in this day and age?
  • by Tiber (613512)

    that the earth may simply stop existing because if it's quantum state. This applies to the universe as well.

    This is why this isn't news.

  • If, in a billion years, we can't change the gravitational constant of the universe by extending the warp field around the rogue planet and tow it back to its proper orbit, then we're sunk anyway. Either that or just call "Q"!
  • Wait, so given enough time, massive objects in relatively close proximity to one another might drift together? Holy shit!

  • by selven (1556643) on Thursday June 11, 2009 @11:24AM (#28295457)
    Even if they can somehow account for every small asteroid that will change the course of Earth's orbit over a billion years, they can't possibly account for the possibility (near-certainty unless we nuke ourselves to death) that we will, possibly before the end of this century, be able to cause drastic changes to anything in the solar system.
  • by The Master Control P (655590) <ejkeever&nerdshack,com> on Thursday June 11, 2009 @04:45PM (#28300925)
    This prediction is as meaningless as the one of Mercury falling into the sun in a billion years for the same reasons.

    The inner solar system is chaotic with a Lyuapanov time on the order of 5 million years - On average, two very nearby orbits will change their distance between each other in phase-space by a constant in that time. This makes the solar system's future evolution profoundly dependent on initial conditions and integrator accuracy.

    First of all it's hard to maintain integration accuracy for more than a few Lyuapanov times, especially when the system has such an enormous dynamic range in mass and characteristic orbital times as the solar system, since this requires that the integrator be exponentially more accurate. The outer solar system is routinely integrated for hundreds of millions of years (and I've run several such simulations myself with a 10th order symplectic integrator) but most simulations of the inner solar system run for a few tens of millions of years at most. A 5 billion year integration of the inner solar system will require that errors be supressed on the order of e^-1000, which is absurd.

    Second of all, chaotic systems are also defined by their extreme dependence on initial conditions. Our observational knowledge of the positions of the planets only extends to about 7 digits at best, which makes any simulation in which displacing something by 1 part in e^1000 changes the outcome meaningless. In addition, at such levels of precision other effects come into play - Relativity changes the details of Earth's orbit significantly from the classical prediction after about 10 million years.

    You can plug whatever numbers you want into a symplectic integrator and it'll run as long as you want without blowing up, but that doesn't mean the numbers mean anything.

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