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Space Science

Planets May Form in Hundreds, Not Millions, of Years 93

Posted by timothy from the presto-formo dept.
Seanasy writes "Recent simulations on the Pittsburgh Supercomputing Center's Terascale Computing System suggest that planet formation may take a lot less time than previously thought. The results were published in SCIENCE."
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Planets May Form in Hundreds, Not Millions, of Years More

Planets May Form in Hundreds, Not Millions, of Years

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  • I'm going to go build my planet RIGHT NOW!!

    AFKCFPSBBI1H
    (Away from keyboard currently forming planet should be back in 1 hour)
  • The headline will be: "Um, planets may be formed in slightly under a week. Scientists all over shocked and suprised." :-)
  • It has been discovered that scientists actually set there game of Civ^W^W^W planet simulator to run at several times normal speed. More on this as it developes.

  • Correction: gas giants & abstract (Score:4, Informative)

    by MacAndrew ( 463832 ) on Thursday December 12, 2002 @03:00PM (#4873209) Homepage
    The study actually looked at gas giants like Jupiter and Saturn. My understanding is that these planets formed by scooping up gas as they orbited the sun. The interior rocky planets of the inner disk probably took longer to achieve final shape, though their materials would have been the first to cool into solid form.

    Neat stuff.

    Here's the Science abstract:

    A Quickie Birth for Jupiters and Saturns
    Richard A. Kerr

    On page 1756, a group of astrophysicists presents computer simulations of the nascent solar system that suggest a possible mechanism for the formation of the gas giant planets: runaway fluctuations in the density of the protoplanetary disk. In their model, gas giants of about the right size, number, and orbit condense from a disk of gas to look like very young Jupiters. The trick was to simulate the process in fine detail so that the gas's own gravity could take over.

    Full Text

    • More abstract (Score:4, Informative)

      by MacAndrew ( 463832 ) on Thursday December 12, 2002 @03:04PM (#4873236) Homepage
      Odd, they have a different abstract from the summary. Sorry, I don't have a full subscription to Science.... not that I would blow their copyright and post it here. :)

      To wit:

      Formation of Giant Planets by Fragmentation of Protoplanetary Disks

      Lucio Mayer,1*dagger Thomas Quinn,1* James Wadsley,2 Joachim Stadel3dagger

      The evolution of gravitationally unstable protoplanetary gaseous disks has been studied with the use of three-dimensional smoothed particle hydrodynamics simulations with unprecedented resolution. We have considered disks with initial masses and temperature profiles consistent with those inferred for the protosolar nebula and for other protoplanetary disks. We show that long-lasting, self-gravitating protoplanets arise after a few disk orbital periods if cooling is efficient enough to maintain the temperature close to 50 K. The resulting bodies have masses and orbital eccentricities similar to those of detected extrasolar planets.

      1 Department of Astronomy, University of Washington, Seattle, WA 98195, USA.
      2 Department of Physics & Astronomy, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4M1, Canada.
      3 University of Victoria, Department of Physics and Astronomy, 3800 Finnerty Road, Elliot Building, Victoria, BC V8W 3PG, Canada.
      * To whom correspondence should be addressed. E-mail: lucio@physik.unizh.ch, trq@astro.washington.edu

      dagger Present address: Institute of Theoretical Physics, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.

  • earth (Score:2, Interesting)

    by iamjim ( 313916 )
    After checking out all of the articles I did not see a mention as to a possible recalculation or restatement of the age of planets in our solar system.

    Is it a possibility that any of the planets, including earth, are much younger than previously thought?

    If so it could offer some information on how quickly life actually "forms".
    • The age of the solar system is around 4.5 billion years. If the earth took less time to form, that would make it older, not younger (if you say it's "birth" is its formation).

      I think it's time to link to talkorigins.org in my sig.
    • I think they very recently discovered some sedimentary rock of an age close to the 4.5 billion figure, and that life has been believed to go back maybe 3.8 billion years for some time now. These estimates are based on radioactive decay and the like rather than theoretical models of solar system formation (or so I understood it). It would surprising if the estimates were off by much, but we've had surprises before.

      When life forms must depend to a certain extent on chance, though to be the fact Earth has almost always had life suggests that maybe it's not that phenomenal a miracle, at least for simple single-celled creatures of extreme simplicity.

      The universe's age is also a topic of speculation, based on the rate of expansion and current size, etc. Stay tuned. :)
      • The article is one how -quickly- planets -formed-, not how old they might be. It doesn't contradict the data you mention in any way.

        It's also about gas giants rather than earhtly bodies.
        • Yep. I never saw a contradiction. But here, does it matter? I spun out my thinking elsewhere in this thread; if you look at it, then TWO people will ever read it. :)
    • Uh, life forms in 6 days doesn't it?

  • PSC (Score:4, Informative)

    by Hadean ( 32319 ) <hadean.dragon+sl ... g m a i l . c om> on Thursday December 12, 2002 @03:05PM (#4873253)
    Here's [psc.edu] a direct link to PSC's article, which does -not- require registration (bah).

    As mentioned by another post, we're talking about "Jupiter-like" gas giants, not Earths. The reason it can't take millions of years: "The problem with [the current model], however, is that if the formation process takes too long, nearby stars will, in effect, boil off the gas envelope."

    • Re:PSC (Score:4, Informative)

      by Hadean ( 32319 ) <hadean.dragon+sl ... g m a i l . c om> on Thursday December 12, 2002 @03:08PM (#4873271)
      Oops, for some reason I didn't realize there already was a direct link... Ah well, here's a copy of it in case it gets Slashdotted (gotta have a real reason to reply, right?):

      "Planets May Form Faster than Scientists Thought"

      Simulations at Pittsburgh Supercomputing Center show that planets can form in hundreds of years.

      PITTSBURGH, December 11, 2002 -- Taking advantage of the computing capability of LeMieux, the Pittsburgh Supercomputing Center's terascale system, scientists have determined that large, Jupiter-like planets -- similar to those observed outside Earth's solar system -- can form in dramatically shorter periods of time than previously thought.

      The findings, published in SCIENCE (Nov. 29), challenge accepted thinking that it takes millions of years for such planets to form from the pancake-shaped nebula of gas and dust swirling around young stars.

      "We used a new model of planet formation," said University of Washington astrophysicist Thomas Quinn, who led the research team, "that couldn't adequately be tested without this kind of computing power, and we found that these giant planets can form in hundreds of years, rather than the millions that the standard model predicts."

      Using LeMieux, the most powerful system in the United States committed to public research, the researchers carried out a series of planet formation simulations. Because of LeMieux, the researchers were able to include roughly ten times more detail than previous similar work, and this increased resolution led directly to the new findings.

      Nearly 100 extrasolar planets have been detected within the past decade, with masses that range from roughly the size of Jupiter to ten times larger. These discoveries prompted thinking about how large planets, similar to Jupiter and Saturn, form. Called gas giant planets, these planets have most of their mass in a gaseous envelope that surrounds the solid core.

      The standard model holds that a core of solid matter congeals from the swirling disk -- called a protoplanetary disk -- around young stars, a process thought to take a million years or so, with another million to ten million years to accumulate the gaseous envelope. The problem with this model, however, is that if the formation process takes too long, nearby stars will, in effect, boil off the gas envelope. "If a gas giant planet can't form quickly," said Quinn, "it probably won't form at all."

      An alternative model holds that giant planets form directly from instabilities in the protoplanetary gas, without the need for a solid-matter core. Until the recent simulations, this model hadn't produced convincing results. "The main criticism," said Quinn, "was that this model wasn't ready. Nobody was making predictions with it. But that's because they didn't have enough computational horsepower."

      The recent simulations -- using 30,000 processor hours on LeMieux -- produced a distribution of masses and orbits comparable to observed extrasolar planets. According to the astronomical findings since the mid-1990s, these gas giant planets appear to be fairly common. "If these planets can't form quickly," says Quinn, "they should be a relatively rare phenomenon, and if they form according to this mechanism they should be relatively common."

      Authors of the research, besides Quinn, are Lucio Mayer, a former University of Washington post-doctoral researcher who recently joined the University of Zurich, James Wadsley of McMaster University, Ontario, Canada and Joachim Stadel at the University of Victoria, British Columbia, Canada.

      Established with an August 2000 grant from the National Science Foundation, LeMieux comprises over 3,000 Compaq Alpha EV68 processors, providing over six teraflops (six trillion calculations a second) of computational capability to U.S. engineers and scientists.

      The Pittsburgh Supercomputing Center is a joint effort of Carnegie Mellon University and the University of Pittsburgh together with the Westinghouse Electric Company. It was established in 1986 and is supported by several federal agencies, the Commonwealth of Pennsylvania and private industry.

  • Geez! (Score:1, Offtopic)

    by Asprin ( 545477 )

    Have you ever checked out the software user-reviews on Spyware Central ^H^H^H^H^H^H^H^H^H^H uhhh, I mean download.com? Talk about pimping for the man!

    • Re:Geez! (Score:3, Funny)

      by Teancom ( 13486 )
      And in a desperate attempt to correllate this poster's comment with the story that it is attached to:

      "I have not checked out those reviews, but they must have been written very quickly!"

      Crap, that's not funny to me either :-(

      Oh, well, I guess there is no way to make the previous poster's comment make sense in this context. Say lah vee!


  • The article says it took 30,000 processor hours to compute. The computer has 3,000 processors in it, so did it take 10 hours of actual time?

    They say that they were able to include 10 times the detail of previous simulations because of the power of the machine.

    Perhaps the Seti@home folks could lend some cycles to similar endeavors that are clearly related to their goals. It seems to me they could do it in less than 10 hours...

    • Seti@Home couldn't handle this type of problem. This is parallel processing -- where nodes work on different parts of the problem at the same time. The catch is that the work done by each node affects other nodes so that super-fast connections between nodes is a must. Otherwise, nodes sit idle waiting for data. Doing this in a disributed manner on the Internet isn't even feasible.

  • They created a planet rather quickly at the end of Titan AE. Planet Bob, wasn't it? =)

    If it takes hundreds of years naturally, could modern technology (read: nonexistant future technology) speed the process up (just like medicine can help speed up the healing of a wound)?
    • What pissed me off about that movie was that they formed an iron-nickel cored planet, complete with silicate mantle and biosphere out of nothing but dirty ice. Uh huh.

      I can see some kind of generated gravitational field device (like an artificial black hole?) that would put a rubble field into a coalescent state of mind. But it would still take a very long time for the elements to sort themselves into something approaching the current layered effect, to say nothing of cooling down to the point of being habitable. And even then you've still got an atmosphere that would eat a hole in your carpet. It took billions of years for the self-maintaining oxygenating system we have today to develop, and it is dependant on far more than just having the right gasses sitting around.

      Anyways, if you've got a Type II civilization with that kind of mega-engineering skill, what are you doing screwing around with ordinary planets? Dyson Spheres and Ringworlds would be a far more efficient use of your building material.

      • Dyson Spheres and Ringworlds would be a far more efficient use of your building material.

        Umm, we're talking FANTASY here. Get a sense of perspective, fer crying out loud!

        If you want reality, calculate the tensile stress on the Ringworld structure and explain to me how something composed of ordinary matter could survive it.

        • Look, the whole point of scence fiction is to create some semi-believable technology and use it as a plot device. If it, or indeed any other plot device, is unbelievable, it ruins the effect. Neither of us would enjoy an action movie in which the Supreme Ultimate Head Honcho Bad Guy Bent on World Domination has a change of heart, surrenders to the hero, and retires to a peaceful cabin in the woods. It's blatantly unreal. It simply would not happen. Similarly, the widgets in a sci-fi simply have to not be stupid. How many times do you see a perfectly usable gadget being ignored in favor of more aesthetic (sp?) plot? I for one find it extremely irritating.

          And anyway, the uber-high tensile strength is needed in _The_ RingWorld since it's 600 million miles around. _A_ Ringworld could easily be made much smaller and built around a smaller, dimmer, longer-lived star. Heck, given the amount of effort needed to build one, it probably would be. One can also build free-floating rings with dimensions in the mere thousands of miles. We could probably build something like that with current tech.

          • ... the whole point of scence fiction...

            And that's where we disagree. You call Titan AE science fiction; I call it fantasy. I agree that it makes very bad science fiction, but as fantasy goes, it's at least as good as the vastly more popular "Dragonball Z".

            Of course, I wouldn't pay money to see either one of them...

            • Fantasy is pretty much the same, only instead of phasers, gravitic generators, and self-aware machines you have wizard's staffs, magical incantations, and elven swords. The use of those items has to be believable (via the initial suspension of disbelief, of course) and self-consistent lest it totally ruin the effect.

              Oddly enough though, Douglas Adam's Hitchikers Guide books (I happen to have been reperusing them) violate these principles every other page and yet are still excellent reads. Shrug.

              • Fantasy with Sword&Sorcery. You're ascribing properties of a subgenre to the whole genre.

                However, you're right about self-consistency and plot. Not that the time to form a giant gaseous planet is usually much relevant to any plot, but we all like our (fantasy) worlds solidly built.

          • You mean like an Orbital, a-la Iain Banks?

            Rotating ring, you live on the inside surface, like a ringworld.. but it doesn't go around a star. it orbits the star like any other planet. The ring is tilted at an angle, though, so that part of it eclipses the rest, providing a day/night cycle.
  • Wow. And to think that Velikovsky was just about run out of the scientific community 50 years ago for putting forth a similar idea, among others -- that planets could form rather quickly, in years or hundreds of years, rather than the millions of years previously thought.

    This is also sort of the subject of James P. Hogan's novel, Cradle of Saturn [jamesphogan.com]. If you've never read James P. Hogan, you should. Good, good stuff.
    • Yes, but Velikovsky was also run out of the scientific community because he thought Biblical and mythical miracles/catastrophes were caused by Venus being ejected from Jupiter and rampaging around the Solar System before somehow settling into its current orbit. That's still mighty unlikely.

      For example, he stated that the "day the sun stood still" at Jericho, so the Israelites could take their vengeance, was caused by Venus making a close pass to the Earth. It passed just perfectly so as to stop the Earth's rotation. It then came back just one day later and perfectly restarted the rotation exactly as before.

      Nevermind the fact that people didn't get flung into space when the rotation suddenly stopped... he's saying Venus passed INSIDE the orbit of the moon, twice! Don't you think they would have mentioned that somewhere in the story? :-)

      (You decide for yourself whether I was being redundant when I said "Biblical and mythical". Trying not to get too far off topic, here.)

  • Sure, but... (Score:5, Funny)

    by Myco ( 473173 ) on Thursday December 12, 2002 @10:27PM (#4877300) Homepage
    It takes much longer to get the fjords just right.

  • but... (Score:3, Insightful)

    by Transcendent ( 204992 ) on Friday December 13, 2002 @12:07AM (#4877789)
    Where do you draw the line as when the process begins/ends?

    You have a large number of events that need to be carried out before the actuall planet sphere begins to form...

    1) Matter needs to be created

    2) A vast ammount of gas needs to slowly collect together.

    3) A stable center of gravity needs to be distinguished

    4) That gravity needs to slowly (and exponentially) gather more mass around it to finally form the planet.

    But when do you start the stop-watch? Step 1... or 4?

    It's like saying "I can put together a ham sandwich in 30 seconds!" ...but how long did it take for all the parts to form like raising the pig or growing the wheat?

    If you go back far enough, it took billions of years for that sandwich to be created... since the beginning of time...

  • Understanding the "hot Jupiters" (Score:4, Interesting)

    by Drog ( 114101 ) on Friday December 13, 2002 @12:09AM (#4877801) Homepage
    For anyone interested in more details, this story appeared here [scifitoday.com] a week ago. An interesting comment pointed out that this theory has major implications in understanding the hundred or so "hot Jupiters" that have been found around other stars. Most have orbital periods of only a few days and orbit their star at a distance less than Mercury's. This new theory may suggest that hot Jupiters are actually newly-formed gas planets and perhaps even a transient phenomena.
  • According to myth, the Earth was created in six days. Now, look out! Here comes Genesis! We'll do it for you in six minutes!

  • They were using g=9.8 instread of G=6.67*10^-11
  • What does this do to the Drake equation/formula?

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