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Is the sun visible if you're standing on the moon?

  1. Sep 2, 2012 #1
    My educated guess is that you can see the sun if you were standing on the moon. Having said that, why isn't there any pictures of the sun taken by astronauts who've "supposedly" walked on the moon..? This seems odd to me.
     
  2. jcsd
  3. Sep 2, 2012 #2

    Drakkith

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    Of course. What do you think is lighting up the landscape of the Moon? There are very few, if any pictures because trying to take a picture of the Sun with a camera without proper filters is practically impossible. Overexposure is going to happen, and then your picture is useless.
     
  4. Sep 2, 2012 #3

    mfb

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    You will rarely see pictures of the sun taken on earth for the same reason. You need special filters, and if you are on the moon there are more interesting objects to photograph.
     
  5. Sep 2, 2012 #4

    jtbell

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    Most pictures of the sun taken from the earth are of sunsets and sunrises, where the light is attenuated by the atmosphere and/or clouds, and you have pretty colors to make a nice picture of. Sunrises and sunsets on the moon wouldn't be nearly as interesting because of the lack of atmosphere, and the landings always took place when the sun was high in the lunar sky anyway. Remember a "day" on the moon is 28 earth-days long.
     
  6. Sep 2, 2012 #5

    russ_watters

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    I wonder what's casting all of those shadows in the pictures.... :rolleyes:
     
  7. Sep 2, 2012 #6

    trollcast

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  8. Sep 2, 2012 #7
    yes unless it is a lunar eclipse on the earth
    :D
     
  9. Sep 2, 2012 #8

    phinds

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    So, are you a conspiracy theorist who thinks people have NOT walked on the moon? That statement sure makes you sound that way.
     
  10. Sep 2, 2012 #9

    Integral

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    Obviously, the stage lights!
     
  11. Sep 2, 2012 #10
    Thanks for the pics. However, the sun sure doesn't look like it's high in the sky. If the sun was high in the sky, there wouldn't be long shadows.

    If the earth is 49 times bigger than the moon, how can the earth look so far away as seen in picture AS17-134-20387..? The earth should always look bigge and/or closerr than the moon does from earth, but in this picture, the earth looks smaller and/or farther away than how we see the moon from earth.

    I do have some doubts about man walking on the moon. Trust me, I do want to believe everything we are told, but because of past coverups, i.e. roswell crash, my wife lying about her cheating on me, I need to question things and get absolute proof to satisfy my mind.

    Things aren't always what they appear to be, and this statement should ring true to scientists.
     
  12. Sep 2, 2012 #11

    trollcast

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    To look at the figures quickly, I've rounded to make it easier.

    If we consider the earth to be 13000km in diameter, and the distance to the moon is roughly 38000km.

    Then the angle at your eye corresponding to the width of the earth is roughly, 0.035 radians.

    Then to scale that to an object 1 meter away from your eye, about an arms length, is about 3cm wide.

    So get a ruler and hold it at arms length and look at how small 3cm is.

    Disclaimer: This post is probably dramatically mathematically inaccurate
     
  13. Sep 2, 2012 #12
    IIRC, one of the Apollo missions did not return good TV footage because the camera was ruined by being accidentally pointed at the Sun.

    Buzz, the size of the Earth in those pics is limited by the focal length 'zoom' of the camera. The landing pair had no need for a 'super zoom' lens to do their scientific work. In fact, a long lens would be a drawback given the problems of aim and manual focus. Pretty pics of Earth were a bonus.

    No offence, Buzz, but six pair of Earthmen did so walk on the Moon. Even the habitually paranoid USSR accepted and acclaimed that. If you want a second opinion, you may have to wait for the Chinese missions to snap some souvenir photos...
     
  14. Sep 2, 2012 #13

    Integral

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    Perhaps you need to step outside and do some local observations. Look at your shadow at noon and at sunset, where is the sun, what does your shadow look like? If you really want the truth, open your eyes.

    And your size reference is?
    Clearly you were not old enough to have been aware in 1969. Now you give more credence to anonymous web pages then men like Neil Armstrong and Buzz Aldrin. Think a bit about your sources of info.
     
  15. Sep 2, 2012 #14
    OK, I will admit that it would be pretty difficult for 40,000 scientists to cover something up for 40 years.
     
  16. Sep 2, 2012 #15
    I'm sorry about the earth being 49 times bigger than the moon. I looked it up last night and for whatever reason, that's what came back. I may have interpreted the earth having 49 times more volume as being 49 times bigger. It was late and I apologize.
     
  17. Sep 2, 2012 #16

    Integral

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    Actually that is not what I was talking about, when you look at the picture of the earth taken from the moon, what are you using to be able to compare to the size of the moon from earth. There is virtually nothing in those pics that lets you make a meaningful judgement of the size.
     
  18. Sep 2, 2012 #17

    Drakkith

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    Well, realize that you also have no source of reference to gauge the "apparent" size of the Earth, as the camera does not reproduce what the human eye sees. How big something appears in a photograph may or may not be anywhere close to what you yourself would view it to be if you were there.

    For example, consider the picture here: http://apod.nasa.gov/apod/ap070926.html
    This picture makes the moon look enormous! Obviously the moon does not actually look this big when you see it with your eye.
     
  19. Sep 2, 2012 #18

    mfb

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    @trollcast: You have a typo in your moon distance (missing 0), but the values afterwards look correct.

    A human head is ~20cm wide, I would expect something like ~40cm outer diameter for the helmets, and the ratio of earth size / helmet size in the image is something like 1:4. This gives a distance of ~3m for the photographer. Looks reasonable.

    Try to take a photo of a human and the moon at night - you will note how small the moon appears from earth (even compared to earth as seen from moon). You usually see the moon somewhere in the night sky, without reference size - it just looks bigger that way.

    Retroreflectors?


    Below the images, the angle of the sun is shown - it is not extremely high, but they certainly landed when it was day.
     
  20. Sep 2, 2012 #19
    I never thought about it before - but the effect seems the same. If the sunlight is behind you on the moon - the illumination of objects is brilliant. If the sunlight is in front of you - it would be quite difficult to focus.
     
  21. Sep 3, 2012 #20
    When I look up at the moon here from earth, the moon has a certain size. It may vary from time to time, but I have a good picture in my mind of how big it looks and/or how the smallest it will look. Based on the smallest the moon can look, if the earth is bigger than the moon (4x), then the earth will never look smaller in the sky when standing on the moon, then the moon looks standing on the earth. In the picture I referenced, the earth looks smaller in the sky than the moon does here on earth. That was my observation.

    Saturday night, there was a program on TV showing video clips of the landing on the moon and the take off from the moon. I was watching very closely the takeoff. There was a camera on the lunar lander, with the flag in it view, just before takeoff. I'm not sure how thick the flag pole is or how deep it is in the moons surface. I don't think it would be very deep if it was only twisted into the ground by hand, or having said that, it would be planted very sturdy.

    Now with the flag pole in view, you could also see footprints in the ground around the pole. As the lunar lander took off, there was much wind pressure from the engine to set the flag flapping wildly, as seen through the camera. Oddly enough, the pole did not bend or topple over. Also, the footprints did not disappear with large amounts of dust blowing up from the ground. As you can imagine, this seemed very odd to me, as I would expect to see something different than what I saw. I'm only stating what I saw on the video, which leaves me wondering, as well as others I would assume.

    Having said that, since the flag pole did not topple over, and the flag was flapping wildly from the power of the engine thrust, would the flag still be flapping today..?
     
    Last edited: Sep 3, 2012
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