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Funny observations from Earth

  1. Apr 28, 2008 #1
    Hi all!

    This is my first post here, so please correct me if I am doing anything wrong. Before I posted this thread here, I read some of the other threads in the subject "General Astronomy", and now I am not sure, that this thread blends in with the other articles, since my question is far more simple than questions in other threads, but anyway...

    I have always wonderd why the sun and the moon looks bigger when rising and setting, than when they are highest on the sky. If anyone could give me a clue or answers the question, I will be very thankful.

    Best regards
    dane502
     
  2. jcsd
  3. Apr 28, 2008 #2

    Kurdt

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    I think thats generally regarded as being an optical illusion. Other theories about atmospheric lensing have been rejected. Here is an enormous article about the whole phenomenon.

    http://www.lhup.edu/~dsimanek/3d/moonillu.htm
     
  4. Apr 28, 2008 #3
    Welcome to PF Dane502,

    Isn't it considered opposite?
     
  5. Apr 28, 2008 #4

    Kurdt

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    What do you mean by opposite? As in the moon would appear smaller at the horizon?

    Atmospheric lensing would cause a slight decrease in the apparent size of the objects but it is well known that in actual fact they appear bigger to us despite this. Have a look at the link I provided. There is also a summary on bad astronomy with a couple more links about the moon illusion.

    http://www.badastronomy.com/bad/misc/moonbig.html
     
  6. Apr 28, 2008 #5

    russ_watters

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    You sure about that? When learning celestial navigation, we used an altitude correction that traced the "true" position of an object below where it was viewed to be. Translation: it stretches vertically (at the very least) as it approaches the horizon.
     
  7. Apr 28, 2008 #6

    Kurdt

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