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This article is marked as 'retired'. The information here may be out of date, incomplete, and/or incorrect.
The sky is blue, and everyone knows why (There is a physical phenomenon called Rayleigh scattering that causes light to scatter when it passes through particles that have a diameter one-tenth that of the wavelength/color of the light. Sunlight is made up of all colors of light, but because of the elements in the atmosphere, mostly nitrogen, the color blue is scattered much more efficiently than the other colors).
What people don’t realize is that all that diffraction between air molecules and dust bounces light every which way. If you’re out under the afternoon sun, and you look at the shadow at your feet, it’s a dim outline, but it obscures nothing. Everything that was visible in the light is there in the shadow, and we take it for granted. But on the surface of the moon, where there is not atmosphere to play havoc with the photons, shadows are stark. Broad daylight is completely blanked out by the body in its path.
The Apollo Chronicles from Science@NASA relates the tales of the Apollo astronauts dealing with the tricks of light and shadow. Most are simple things about being unable to read a recessed gauge or the like, but one recollection stood out to me:
The astronauts could see Surveyor 3 from their lunar module Intrepid. “I remember the first time I looked at it,” recalls Bean. “I thought it was on a slope of 40 degrees. How are we going to get down there? I remember us talking about it in the cabin, about having to use ropes.”
But “it turned out [the ground] was real flat,” rejoined Conrad.
What happened? When Conrad and Bean landed, the sun was low in the sky. The top of Surveyor 3 was sunlit, while the bottom was in deep darkness. “I was fooled,” says Bean, “because, on Earth, if something is sunny on one side and very dark on the other, it has to be on a tremendous slope.” In the end, they walked down a gentle 10 degree incline to Surveyor 3—no ropes required.
Travel to the moon to be befuddled by a shadow. The things we take for granted …
Related links:
RedOrbit Article
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This blog entry really shines (without a shadow of doubt).
Bucky said: “This blog entry really shines (without a shadow of doubt).”
Lamzors
A key goal of the Apollo 12 mission was to visit Surveyor 3, to retrieve its TV camera, and to see how well the craft had endured the harsh lunar environment.
Alright, go on. Put the mystery to rest already. What happened to the camera? You’re not going to leave us hanging now are you Jason? Damn “damn interesting” anyhow! Okay I will end it. Here is what they found and here is a more detailed version of the story.
Damn! Another mystery. How to post a quick url link here?
Arcangel said: “Damn! Another mystery. How to post a quick url link here?”
Just use standard HTML <a> tags… but I fixed the two in your last comment.
I bet the fact that the lack of shadows in the pictures on the moon is one of the arguments used by those who feel the moon landing was a conspiracy. Perhaps this bit of news will help them appreciate moon atmosphere trickery.
I’m not too familiar with the moon landing conspiracy theory, but isn’t the point of this article that on the moon, there ARE shadows, and that they are really stark? Therefore, there SHOULDN’T be a lack of shadows, which apparently is what is seen in many of the moon photos… or something like that.
JustAnotherName, Jeeves: If you look at various moon pictures, you’ll see that the shadows aren’t always completely black, and neither is the shadow side of the lunar modules, space suits etc. The conspiracy ‘enthusiasts’ think that this is proof of an atmosphere, and hence a conspiracy. In fact it’s just light reflected from other surfaces, enhanced by the ‘halo effect’. More info (with links to demonstrations of both effects) here: http://www.badastronomy.com/bad/tv/foxapollo.html#shadow
Arcangel said: “Alright, go on. Put the mystery to rest already. What happened to the camera? You’re not going to leave us hanging now are you Jason? Damn “damn interesting” anyhow! Okay I will end it. Here is what they found and here is a more detailed version of the story.”
DI Arcangel!
They found bacteria on the camera which had originally come from earth! 31 months without air or water, living through huge temperature variations and massive doses of UV light!
Panspermia, anyone?
Except there are better explanations:
http://en.wikipedia.org/wiki/Reports_of_Streptococcus_mitis_on_the_moon