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Saturn's New Moons Named

Posted by CowboyNeal on Sat Feb 26, 2005 10:14 AM
from the huey-dewey-and-louie dept.
sebFlyte writes "The BBC is reporting that three new moons found orbiting Saturn at the end of last year have been named. 'Two moons detected in August have been given the names Methone and Pallene, while another found in October has been provisionally named Polydeuces.' Polydeuces is also reported as being a very strange object-- a trojan moon. It sits in a spot near a larger moon where the gravitational pull of the other moon (Dione here) and the planet cancel each other out."
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  • Polydeuce bigalow.

    Planet Gigolo
  • by Anonymous Coward on Saturday February 26 2005, @10:16AM (#11786918)
    That's no Trojan moon...
  • Lagrange Points (Score:5, Interesting)

    by dj42 (765300) * on Saturday February 26 2005, @10:18AM (#11786930) Journal
    I hadn't ever really thought about Lagrange points before I read that article. They are both interesting and intuitive to me. That there is a spot between two gravitational bodies that creates a "dead" spot, around which an object can orbit in a tug of war. Neat stuff. I find that more interesting than what names they have chosen for the moons.
    • I find that nerds are always using phrases such as:

      "Yes, that's quite intuitive to me."

      Don't they know that these phrases convey no useful information and only serve the purpose of making the nerd seem even more self-centered and arrogant?

      Sure, you can impress us and show us how smart you are, but please don't do it by telling us "golly, i'm so smart."

      It's quite obnoxious.
      • "I find that nerds are always using phrases such as: "Yes, that's quite intuitive to me."
        Don't they know that these phrases convey no useful information and only serve the purpose of making the nerd seem even more self-centered and arrogant? Sure, you can impress us and show us how smart you are, but please don't do it by telling us "golly, i'm so smart."

        I felt saying it was "intuitive" conveyed useful information: the fact that I don't any real understand of the mechnics involved, but that it "feels right
        • It's exactly that, the arrogance of not having any clue about the actual math involved, but still claiming to be able to tell which statements "feel right" and which don't.

      • I find that morons are always using phrases such as "Don't they know that these phrases convey no useful information and only serve the purpose of making the nerd seem even more self-centered and arrogant?" Next time you don't "get it", just stay quiet. As they say, "it is better to remain silent and appear a fool than open your mouth and remove all doubt."
    • Re:Lagrange Points (Score:5, Interesting)

      by Eosha (242724) <esomasNO@SPAMhotmail.com> on Saturday February 26 2005, @11:04AM (#11787220) Homepage
      There are five Lagrange points between any two bodies. L1,L2 and L3 lie inline with the bodies and are unstable (i.e., the slightest perturbation and you fall off). However, L4 and L5 are located off to the side, where the point and the two bodies form an equilateral triangle in the plane of the orbit. L4 and L5 are stable (you can have stable orbits around them). Trojan asteroids have been found at the Jupiter-Sun L4 and L5 points, but I believe this is the first planet-moon case.
  • by Evil W1zard (832703) on Saturday February 26 2005, @10:19AM (#11786935) Journal
    Yikes better update my anti-virus. Don't want to get infected by W32.Polydeuces.A@mm now.
  • by bossesjoe (675859) on Saturday February 26 2005, @10:20AM (#11786947)
    ....Methone and Pallene, Polydeuce? Where's the cowboy neil option?
  • Stability? (Score:3, Interesting)

    by Ulric (531205) on Saturday February 26 2005, @10:20AM (#11786948) Homepage
    "It sits in a spot near a larger moon where the gravitational pull of the other moon (Dione here) and the planet cancel each other out."

    How can that possibly be stable? Wouldn't the slightest deviation lead to the moon coming crashing down in either direction?

    • Same thing as normal moons.

      Linky goodness. [montana.edu]
    • by dj42 (765300) * on Saturday February 26 2005, @10:27AM (#11786996) Journal
      I believe the way the Lagrange points work (from what I read) is that the object "in it" orbits the lagrange point by being tugged back and forth... it's not just "sitting there at some fixed distance relative to the 2 bodies.
      • by C Siren (862991) on Saturday February 26 2005, @10:53AM (#11787170)
        Ok -- Newton's 1st & 2nd laws tell you that if you have unbalanced forces acting on an object (like a moon), that will result in an acceleration on that object. Acceleration is change in velocity, i.e. speed and direction. A moon going around in an orbit is constantly changing direction and needs a particular centripetal acceleration to stay in that orbit.

        In celestial mechanics, Lagrange points come up in the three-body problem, where you have two large bodies (eg Sun and planet, planet and large moon) and one small object (a Trojan asteroid, spacecraft, new Saturn moon).

        Lagrange points are the five places relative to the two large objects, where the third object will be held at the same position - relative to those two objects - in its orbit. In other words, there will be a net force on the third object that will result in it accelerating around the largest object at the same rate as the second largest object.*

        A Lagrange point is stable if an object near by the L point will tend to be pulled towards or orbit around that point if it's a bit off the exact point. The L point is unstable if the object tends to be pulled further away from it once it wanders a little away.

        The L1 point (in between the two large bodies), L4 and L5 points (60 deg ahead and behind the orbiting large body) are stable, the L2 and L3 points are unstable. Many of our solar observing spacecraft get sent to orbit the L1 point.

        *(Center of mass discussion left out for relative simplicity)

    • RTFA it has a 55 deg. deviance (give or take) over the course of two years.

      The lagrange spot isn't an absolute, just as with any field, there will be areas of decreasing influence. The moon can safely deviate within these grey areas, with no fear of crashing down. Seeing as how it's in orbat withing this lagrange area, it is fairly stable, because as per what that means, it's kinda stuck there by opposing forces.

      Should some (fairly large) foreign space object crash into it, then you may have cause to

    • Nope - to give a quick and easy understanding, the Lagrange-points act as "virtual centers of mass", an empty point between or around two large masses that are gravitational wells.

      You can orbit around a stable L-point, and an object "floating" (i.e., little acceleration relative to the point) near it will tend to be attracted to it - and thus be stable (there are unstable Lagrange points as well, which are points in the gravity interaction that don't function like this, but are still usable).

      L-1 between S

  • by amaline (572260) on Saturday February 26 2005, @10:27AM (#11786995)
    Naming them Ronald and Reagan?
  • Lagrange point (Score:4, Informative)

    by kbonapart (645754) <lashan_lynn@ya[ ].com ['hoo' in gap]> on Saturday February 26 2005, @10:29AM (#11787005)
    The point between to celestial bodies (usually a planet and it's moon) where the gravity of one is equal to the gravity of the other is called the Lagrange point.

    Usually closer to the smaller of the two bodies, this point is a common location of sci-fi space stations, as there is no need to use an orbit to keep the station from decaying back into the larger bodies atmosphere.
  • (Dione here)

    Me too, cya.
  • Naming & Mythology (Score:5, Informative)

    by ornil (33732) on Saturday February 26 2005, @10:37AM (#11787049)
    I was a bit surprised about the name Polydeuces, because he (the mythological character) had little to do with Troy. However, it turns out that there's another Trojan moon called Helene (now this makes sense!), and Polydeucues is Helene's brother.
  • by FunWithHeadlines (644929) on Saturday February 26 2005, @10:38AM (#11787062) Homepage
    SATURN (Galactic News Agency) - The inhabitants of Saturn have announced that they have finally named the moon orbiting the third planet from the sun in their star system. The moon, named Xkeysdy, orbits the blue planet widely known as !3kd8dgh, which renders in Standard Galactic as "that wreteched place full of pushy peons."

    When asked why they had named the moon now after millenia of observation, one student from Saturn's top university said, "Why not, you know? I mean, like, we had named everything else of importance, dude. Even the unimportant places. So like this was all that was left."

    No comment could be received from inhabitants of !3kd8dgh, since they don't speak Standard Galactic. Moreover, they laughably think they are the only inhabitanted planet in the system, and it's considered taboo to disabuse them of this ignorance.

  • by catisonh (805870) on Saturday February 26 2005, @10:46AM (#11787116) Homepage
    Oh Saturn, I love your rings. They make you look so beautiful. I just love being around them for all this time.

    Oh moon, the way you circle around me makes my weather patterns get all disrupted. You are just the perfect little moon, I love you.

    Oh Saturn, I think its time for some gravitational pull...

    ...TROJAN MOON.
  • by glrotate (300695) on Saturday February 26 2005, @10:54AM (#11787171) Homepage
    We can see lightyears and lightyears away with Hubble, and other large telescopes. So how is it were still finding moons in the solar system?
    • by at_18 (224304) on Saturday February 26 2005, @11:12AM (#11787276) Journal
      Because these new moons are very small, and moreover they are very close to a large and bright planet like Saturn, that would outshine it in any telescope field of view.
    • by IO ERROR (128968) * <error.ioerror@us> on Saturday February 26 2005, @11:19AM (#11787343) Homepage Journal
      We can see light from lightyears away. Moons in our solar system don't give off light, and reflect very little. It's the difference between looking around in full daylight, and trying to find a lost marble in the near total blackness of your bedroom.
    • We can see lightyears and lightyears away with Hubble, and other large telescopes. So how is it were still finding moons in the solar system?

      Because we can only see light (well, electromagnetic radiation, to be more precise). While stars give off incredible amounts of light, moons only (poorly) reflect the light from those stars.

    • In addition to what others have said, Saturn has another fun problem with locating moons: some of them are embedded in the ring system. The rings are bright. It's hard to see a small moon in there, unless you get close up and can resolve the gaps the moons clear out (and the moons within them). Or you could wait for a ring-plane crossing, but that's still not a sure-fire method.

      Also, it should be noted that people only started doing CCD-based searches about 7 or 8 years ago. It's sort of a case where a
  • Apparently not many people paid attention to this in high school.

    The title of this article should be: Saturn's New Satellites Named.
  • Who decides on the names of these moons?
  • by CheshireCatCO (185193) on Saturday February 26 2005, @01:55PM (#11788283) Homepage
    As far as I can see from the article and from the IAU website, the International Astronomical Union hasn't approved these names. By common agreement in the astronomical community, they have the final word on approving names. So until they meet and approve this, all that is being reported is that the Cassini team is *suggesting* names for the moons *to* the IAU. The IAU has the right to shoot down their suggestins. (I'm a bit skeptical of Polydeuces being accepted since it doesn't fit the usual scheme. But what do I know?)
      • Helicopters (according to physics) can't fly.

        WTF? Yeah, you're right, they were engineered using imaginary equations. Maybe according to the physics you took (and probably didn't understand) in high school, they can't fly, but to claim the most fundamental science we as humans can grasp can't explain helicopter flight is both incredibly stupid and incredibly closed minded. Spend five seconds googling and you can see the variety of books that exist solely for studying the dynamics of helicopter flight.