2007-12-23 17:03:35 · 9 answers · asked by ningis n 1 in Science & Mathematics ➔ Astronomy & Space
yes tessie, very pretty.
2007-12-24 00:18:54 · update #1
This is a purely psychological effect and has nothing to do at all with the Earth's atmosphere. If you have a night of a full moon, extend your arm fully and hold your thumb over the moon, and estimate the size of the moon against the size of your thumb. Do this when the moon appears large near the horizon, and also several hours later when the moon is closer to overhead. You can prove to yourself that while the moon at the horizon APPEARS larger, it has exactly the same size compared to your thumb no matter its angle in the sky.
The explanation usually given is that near the horizon, you are seeing the moon against the backdrop of other objects, like houses, trees, the horizon itself, but when the moon is overhead you have nothing against which to measure its size. However, many researchers believe this is too simplistic. For a very full review of this phenomenon (called the Moon Illusion) see: http://www.lhup.edu/~dsimanek/3d/moonillu.htm
2007-12-23 17:53:41 · answer #1 · answered by kuiperbelt2003 7 · 2⤊ 0⤋
The moon looks larger over the horizon because there are landmarks in the fore-ground to reference it to. Look up in the sky when it is well above the horizon and it will appear small compared to the vastness of the sky. The size has not changed, just the perspective. This is an optical illusion.
2007-12-24 01:20:48 · answer #2 · answered by scott p 6 · 2⤊ 1⤋
Take a ruler. Hold it at a constant distance from your eyes (e.g. two feet or a yard). Measure the angular diameter of the moon near the horizon and when it is near the zenith.
Can you measure the difference?
Hint: You won't be able to. For all practical purposes of visual astronomy the moon has the same angular diameter near the horizon as it has near the zenith.
2007-12-24 01:18:56 · answer #3 · answered by Anonymous · 2⤊ 0⤋
The moon is always the same size but when it is on the horizon it looks much bigger because there are things close by to relate the size to. Up in the sky it is all on its own so looks smaller.
2007-12-24 02:12:00 · answer #4 · answered by ginga ninja 3 · 1⤊ 1⤋
Nothing to do with the atmosphere making it a larger size in the sky. And it's not because of the comparison with familiar objects, either.
This is the best explanation so far. Strange that science can't find the answer to a simple optical illusion!
http://facstaff.uww.edu/mccreadd/
2007-12-24 03:24:14 · answer #5 · answered by Choose a bloody best answer. It's not hard. 7 · 1⤊ 0⤋
If you had a really sharp eye, you'd note that the 5.49% ellipse of the moon's orbit about the earth can vary your perspective of it's size.
2007-12-27 23:15:14 · answer #6 · answered by te144 7 · 0⤊ 0⤋
The earth's atmosphere acts like a lense. Low to the horizon light from the moon has to travel through a lot more air due to the angle and the effect is like a thick lense optically enlarging it.
2007-12-24 01:15:18 · answer #7 · answered by Osku 2 · 1⤊ 5⤋
What these guys said...Nothing to do with atmosphere...Perspective is the key word.
2007-12-24 02:54:37 · answer #8 · answered by Anonymous · 0⤊ 0⤋
Its an optical illusion. Pretty, huh?
2007-12-24 01:08:56 · answer #9 · answered by Tessie 4 · 2⤊ 0⤋