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Fifty Year Old Moon Mystery Explained

Posted by michael on from the green-cheese dept.

ekarjala writes "This article from NewScientist.com explains that a "flash" on the moon's surface that (captured by an amateur photographer 50 years ago) was probably the result of a 20 meter asteroid hitting the moon's surface."

5 of 43 comments (clear)

  1. Link to actual photo by oni · · Score: 5, Informative

    Here's a tip for Jeff Hecht, the article's author: If you write a piece about a photograph, you *must* link to a copy of the photograph. Mkay?

    For everyone else, here it is:
    http://iota.jhuapl.edu/stuart.jpg

    And here's a much better story about it:
    http://news.bbc.co.uk/2/hi/science/nature/2592075. stm

  2. here's the pic by MJArrison · · Score: 5, Informative

    The linked article doesn't have a pic of the impact they're talking about.
    Here's one I found over at space.com.

  3. Re:where does the light come from? by JabberWokky · · Score: 5, Informative
    All that energy become heat - and heat often radiates as light. Many types of substances will emit light when excited, even in a vacuum. Look at any lightbulb for an example, or even the classic vacuum tubes.

    A metor slamming into rock would easily produce enough energy as heat to produce a flash. (Many other things that produce light without oxygen - I *think* bioluminecence, plus glow sticks, but certainly things like nuclear reactions, which produce quite a bit of light without oxygen being involved. We sophisicated types refer to this as 'daylight'. ;) )

    --
    Evan

    --
    "$30 for the One True Ring. $10 each additional ring!" -- JRR "Bob" Tolkien
  4. Re:where does the light come from? by Idarubicin · · Score: 5, Informative

    This is easier to answer than you might expect. When you have a rock hit the surface of the moon at a relative velocity of many kilometers per second, a good bit of the asteroid's kinetic energy gets converted very rapidly into heat. We're talking about energies on the order of hundreds of thousands of tons of TNT here. For a short period of time, part of the surface and some of the ejected matter will glow white hot, hence the 'flash'.

    --
    ~Idarubicin
  5. Re:where does the light come from? by Dahan · · Score: 5, Informative
    right on the demarcation between light and dark. (It has a name, but I forget what it is.)

    It's the terminator (best read with an Arnold Schwarzenegger accent :)