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Astronomers Want To Hunt Down Earth's Mini-Moons

Posted by samzenpus on from the that's-no-mini-moon dept.

astroengine writes "The Earth has one permanent moon — you know, 'The Moon' — but at any given time there are thought to be two temporary interlopers that were once asteroids, but get captured by our planet's gravity to become mini-moons for a few months or even years. They eventually get flung back out into interplanetary space. This ultimate 'catch and release' provides an interesting opportunity for any future asteroid mission. So now astronomers want to find them, possibly using the newly-minted Hubble-class spy telescopes donated to NASA by the National Reconnaissance Office."

22 of 44 comments (clear)

  1. What a letdown by Anonymous Coward · · Score: 5, Funny

    I was six when I learned that the Man on the Moon wasn't real. And now I'm hearing that he doesn't even do his own stunts.

    1. Re:What a letdown by Gilmoure · · Score: 2

      Yes Sheldon.

      --
      I drank what? -- Socrates
  2. Wacky physics, or... by Anonymous Coward · · Score: 3, Informative

    They left out the part that it's not the Earth alone somehow capturing and releasing these objects, it's the interaction between Earth's gravity and the moon's gravity that can result in a temporary capture.

    1. Re:Wacky physics, or... by osu-neko · · Score: 4, Insightful

      They left out the part that it's not the Earth alone somehow capturing and releasing these objects, it's the interaction between Earth's gravity and the moon's gravity that can result in a temporary capture.

      And the gravity of the Sun, Jupiter, Mars, and your neighbor's Honda Civic... and that's just the tip of the iceburg. Pick a flower, and you move the furthest star. However, listing everything that plays a role in this (which is, literally, everything) is rather cumbersome, so it's fair to simply list the one object that has the greatest influence and leave out the 10^80 other objects involved.

      --
      "Convictions are more dangerous enemies of truth than lies."
    2. Re:Wacky physics, or... by Deadstick · · Score: 2

      it's fair to simply list the one object that has the greatest influence

      I'd go one step further and include the Sun. Solar gravity gradients are within the same order of magnitude as those of the Moon.

    3. Re:Wacky physics, or... by Daniel+Dvorkin · · Score: 2

      If the Earth, the Moon, and the asteroids were the only objects in the universe, the capture would still happen the way it does. If Earth, the asteroids, and the rest of the universe were still present but the Moon wasn't there, it wouldn't. (The asteroids might still be captured by Earth's gravity, of course, but not in the way they are now.) So I think you don't really understand OP's point.

      --
      The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
    4. Re:Wacky physics, or... by aynoknman · · Score: 1

      And the gravity of the Sun, Jupiter, Mars, and your neighbor's Honda Civic... and that's just the tip of the iceburg

      I knew Dirk Gently was right about "the fundamental interconnectedness of all things"!

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      We need a "+1 -- nice sig" moderation.
    5. Re:Wacky physics, or... by DKlineburg · · Score: 1

      I would think the sun has a greater role. It pulled the "moon" into the earth so the earth could capture it in the first place. I'm must saying...

      --
      Memory is deceptive because it is colored by today's events. - Albert Einstein
    6. Re:Wacky physics, or... by RaceProUK · · Score: 1

      I think you don't quite understand how science works.

      --
      No colour or religion ever stopped the bullet from a gun
    7. Re:Wacky physics, or... by OeLeWaPpErKe · · Score: 1

      Way to make an argument. Don't bore people with the details.

      Do you work for Fox News ?

    8. Re:Wacky physics, or... by RaceProUK · · Score: 1

      Way to make an argument. Don't bore people with the details.

      Do you work for Fox News ?

      No, I just can't be bothered arguing.

      --
      No colour or religion ever stopped the bullet from a gun
  3. Mini moons? by Junior+J.+Junior+III · · Score: 2

    Those are space stations!

    --
    You see? You see? Your stupid minds! Stupid! Stupid!
    1. Re:Mini moons? by PhxBlue · · Score: 2

      Not yet, but if we're serious about developing a next-generation space program, then they we should look at making that a true statement.

      --
      !#@%*)anks for hanging up the phone, dear.
  4. so the NRO actually found them by turkeydance · · Score: 1

    the weapons of mass destruction! the mini-moons...what a concept! now NASA gets a peek.

  5. Cruithne by IntentionalStance · · Score: 1

    is a moon of the Earth if you believe Stephen Fry and QI

    1. Re:Cruithne by Turminder+Xuss · · Score: 1

      Cruithne has been referred to as Earth's Second Moon, but it is really in orbit around the Sun in 1:1 orbital resonance with the Earth, whatever that means.

      --
      You seem to regard science as some kind of dodge... or hustle.
    2. Re:Cruithne by IntentionalStance · · Score: 1

      Sure- but watch this though https://www.youtube.com/watch?v=D1zuAQAhhMI

    3. Re:Cruithne by flyingfsck · · Score: 1

      Well, The Moon does the same thing. It orbits the sun and just wobbles a little bit.

      --
      Excuse me, but please get off my Pennisetum Clandestinum, eh!
    4. Re:Cruithne by RaceProUK · · Score: 1

      Cruithne has been referred to as Earth's Second Moon, but it is really in orbit around the Sun in 1:1 orbital resonance with the Earth, whatever that means.

      Co-orbital asteroid. They count as moons if you stretch the definition of 'moon' a bit, as they do trace a complete orbit of the Earth itself (except those that don't obviously).

      --
      No colour or religion ever stopped the bullet from a gun
    5. Re:Cruithne by Turminder+Xuss · · Score: 1

      I think Cruithne is one that doesn't. One way of putting it is that Cruithne is never in Earth's shadow. I'm happy to call it a moon though, if for no better reason than to see Stephen Fry discomfort Alan Davis.

      --
      You seem to regard science as some kind of dodge... or hustle.
  6. where did we get the quantity 2? by MickLinux · · Score: 1

    Having read the article, the Earth may have any number of temporarily captured asteroids.

    Where did the idea come that we have two of them?

    --
    Correct Horse Battery Staple: 72 bits of entropy. Enter "Correct H" into google. When it generates the phrase, that's
  7. Not moons. by PhxBlue · · Score: 1

    If the objects only temporarily orbit the Earth, they're not moons.

    If the objects orbit the Earth-Moon system, they're not moons.

    I know it's pedantic, but accuracy is important, even on /..

    --
    !#@%*)anks for hanging up the phone, dear.