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Moon around Kuiper Belt Object

Posted by michael on from the waltzing-matilda dept.

UncleJosh writes "Today's NY Times (free reg rq'd) has a story about the first Kuiper Belt Object (KBO) with a moon, 1998 WW31. The hubble telescope has been used to get information about the size and orbit of the moon. Seems lots of things have moons. Coming more than 20 years after the discovery of Pluto's moon Charon the discovery of a KBO with a moon also follows the discovery of asteroid Ida's moon Dactyl and other moons of asteriods."

4 of 37 comments (clear)

  1. Read Kim Stanly Robinson by Noodlenose · · Score: 2, Interesting

    In the "Mars" Trilogy by Kim Stanley Robinson he envisions a time when mankind will actually settle on Kuiper Belt Objects to mine them: Nice if you like low gravity. And now you can even see a moon rise :-)

  2. Too bad this isn't in the main section by ramoth4 · · Score: 3, Interesting

    I'd like to see what others think about this, instead of a measly 2 replys.

    This poses major questions though, about what exactly is a planet. Is Jupieter a planet? It puts out more heat than it takes in. What about Pluto? It's not in a regular orbit. What about that whole "Nemesis" theory? What's that got to do with this?

    1. Re:Too bad this isn't in the main section by seann · · Score: 2, Interesting

      apparently, they've ruled out pluto as a planet. I have the reference, but it's in a big book with no cover under my bed holding it up on it's edge.
      I supose they consider jupiter a planet, because it is large. "Gas Giant"

      --
      I'm a big retard who forgot to log out of Slashdot on Mike's computer! LOOK AT ME.
  3. Re:This IS surprising (physics) by Anonymous Coward · · Score: 1, Interesting

    Looks like being an EE major isn't good enough. One way to think about it is this: the law of gravity is time-reversible, if you instantaneously reverse the direction of all bodies, you should see the solar system go back in time. However, collisions and atmospheric drag aren't time-reversible, so you wouldn't get back to the primordial nebula, but you'd get pretty far.

    By time-symmetry, capturing a moon is just as amazing as losing a moon. Reverse time: you have these two bodies orbiting and suddenly they split apart. You have to find a *cause* for this.

    Possible mechanisms to explain a moon:
    (1) the two bodies formed at the same time
    (2) dramatic event, action of a third body
    (3) long term, cummulative action of a third body
    (4) non-reversible mechanism (collision, atmospheric drag)

    If the Sun is responsible as you suggest, the two bodies can't just get to their current orbit by "meeting and traping each other" (case 2) because the Sun is too far to cause a dramatic event. The capture process would have to be spread over millions of years (case 3).

    Personally, I don't see why we shouldn't simply assume case 1.