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The Moon's Two Sides Look So Different Thanks To 4.5 Billion-Year-Old Physics (forbes.com)

Posted by samzenpus on from the good-side-bad-side dept.

StartsWithABang writes: 4.5 billion years ago, a giant object collided with our proto-Earth, kicking up debris that eventually coalesced into the Moon. While the near side contains dark maria and lunar lowlands, the far side is almost exclusive heavily cratered, high-mountainous regions. This was a mystery for a long time, but it appears that heating from the hot, young Earth caused a chemical and crustal difference between the two faces.

4 of 96 comments (clear)

  1. Re:I could be missing something by Michael+Woodhams · · Score: 3, Informative

    As seen from the moon, the Earth is only about two degrees across, so the proportion of projectiles blocked by it would be miniscule. Even that small effect is reduced (possibly beyond zero) by 'gravitational focusing': projectiles which come towards the moon from the direction of the Earth which would otherwise have missed can be deflected by Earth's gravity such that they hit. (And this happens more often than projectiles that would have hit being deflected so they miss.)

    Here is a paper I found on gravitational focusing.

    --
    Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
  2. Re:The moon could have been artificially created. by ClickOnThis · · Score: 4, Informative

    The fact that it always faces the earth,

    Nothing remarkable about that. It's due to tidal locking and is quite common.

    and orbits the earth once every month is very intriguing.

    Yea, and Lou Gehrig died of Lou Gehrig's disease. [cue creepy music]

    --
    If it weren't for deadlines, nothing would be late.
  3. Re:Please StopWithABang by jfdavis668 · · Score: 5, Informative

    The link could have gone straight to the Penn State news article Forbes was reporting on: http://news.psu.edu/story/3178...

  4. Re:I could be missing something by RubberDogBone · · Score: 1, Informative

    You are correct. But this sort of ignorant "X times to a lesser value" bullshit math is rampant. I use it to easily spot stupid people for me.

    Sometimes I will ask them, please draw for me on a blackboard how you would work "20 times less than X" and laugh at them when they can't do it.

      But the scary thing is how many people don't understand what's wrong. It is simply that you cannot multiply and reach a lower value. 10 times less can't work. Ever.

    One tenth can. But fractions are apparently impossible.

    --
    Sig for hire.