Why does the moon appear to drop off in the background of all Apollo moon pictures?

If you look at any of the Apollo moon pictures, the surface of the moon appears to disappear in the background. It's almost as if they are standing near the edge of the moon.


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The moon is roughly 1/4 the size of the Earth, which means that in any picture you should be able to see for miles and miles behind the astronauts. I realize there is a black background, but it still looks as if there is no horizon.





Shouldn't it look the same as if you took a picture here in the desert?





http://www.flickr.com/photos/guide_en_th鈥?/a>Why does the moon appear to drop off in the background of all Apollo moon pictures?
If you calculate the expected horizon distance, it's only about a mile and a half. The distance to a flat horizon is given by this formula:





d = sqrt(Dh)





where ';D'; is the planet's (or moon's) diameter, and ';h'; is the height of your eye above the ground. If you plug in the moon's diameter, and use ';6 feet'; for the height, you get about 1.5 miles for the horizon's distance.





There's an additional visual effect caused by the fact that the moon has no atmosphere. On the earth (as in your sand dune picture), things in the distance sort of ';fade away';; this is due to the obscuring effects of the atmosphere. But on the moon, all the scenery is crystal clear right up to the point where it drops over the horizon. This abrupt disappearance of scenery also adds to the impression that all the scenery is very close. In some Apollo photos, there are mountains that are 5 miles away; but they ';look'; like they're as close as the Lunar Module, because they are just as sharp and clear.





Dr. Harrison Schmitt (who's been to the moon) talks about this effect in the July issue of Scientific American. You can read the article here: (http://www.scientificamerican.com/articl鈥?/a> ). But unfortunately you'll have to get the print issue if you want to see the photographs that nicely illustrate what he's talking about.Why does the moon appear to drop off in the background of all Apollo moon pictures?
For one thing, they landed on a flat spot. There wasn't any mountains or hills in the background.





Secondly, you are thinking backwards. The bigger the planet or moon, the more you would be able to see in the background because the arch angle would be less.
the same reason when you look out into the ocean the horizon line makes it look like it's one big floor you could walk off of...





oh yeah, and there's no buildings on the moon fyi, so take that into perspective
There is no atmosphere on the moon to bend the light to look like what we are used to seeing here on earth.











THINK ABOUT WHAT YOU ASK!!!!
they were restricted to the size of the hollywood movie studio
It doesnt drop off, it's called North and South.
The lack of atmosphere on the moon means there is also the absence of atmospheric extinction. That means something 20 miles away can be seen just as clearly (though smaller of course) as something 1 mile away. Here on Earth, as things fade into the distance, they become washed out due to light passing through air and being scattered. We use that to judge distances. On the moon, this reference does not exist. It actually can be quite disconcerting. You could begin walking in a direction to approach what you think is a boulder only to find it really is a big mountain miles away. The horizon will seem close to you due to this phenomenon.