Can anyone tell me, in detail, why we only see one side of the moon?
435628
sure it has to do w/ the reflection of the light form the sun.
46600
To tell if the moon is waxing (getting bigger) or waning (getting smaller) look at which side of the moon is "filled-in," or visible. If the right side is visible, the moon is waxing (getting bigger.) If the left side is visible, the moon is waning (getting smaller.)\n\nO'course, if you live in the Southern Hemisphere this is the opposite (the left/right visibility factor is reversed.)
208149
The truth is, the moon obviously orbits the earth, right? So you look up and see the moon in the time of day, it is at an angle where other parts of the Earth can see it, sometimes the moon is here in the day time because it is on the same side as we are facing the sun, if it is during the night time, we see the moon because it has orbited behind the Earth, it takes the moon a certain amount of time to get around the Earth.
371904
A month. That's why we only see one side of the moon. (Hence the Pink Floyd song Dark Side of the Moon). :)
108945
You see the darkside during a fullmoon since what you see was the darkside two weeks earlier. I guess you mean the far side. That is a little harder but the Apollo program generated alot of pictures of the farside. Also numerous spaceprobes has mapped the entire surface of the moon. Should be plenty of pictures just on NASAs moon site.
21430
The theories presented so far have been pretty much debunked. The following link gives an elaborate explanation of this illusion. But even it fails to explain why we don't see this illusion every time the moon rises. It does not always appear larger at moonrise than when it is higher in the sky. Also, the moon may appear to be different sizes on different nights even in the same location. I'm still looking for a plausable explanation. \n\nhttp://facstaff.uww.edu/mccreadd/
120878
http://www.grand-illusions.com/moon.htm\n\nThe Moon Illusion\n\nThe moon illusion is one of the most famous of all illusions. Stated simply, the full moon, when just above the horizon, appears much larger than when it is overhead. Yet the moon, a quarter of a million miles away from the earth, always subtends the same angle wherever it is in the sky, roughly 0.5 degrees.\n\nThe first problem is for photographers. A wonderful picture presents itself, with the full moon just rising above a spectacular horizon. Click, the picture is taken. Yet the result is disappointing. The moon seems much smaller in the photograph than it did when viewed with the naked eye. Even professional photographers fall for this one. Yet on a normal lens, 50mm on a 35mm camera, the field of view is around 50 degrees, and the width of the moon, subtending an angle of 0.5 degrees, will be 100th of the width of the photo! Many photographs that you see in magazines, containing both a moon and a landscape, will be composites. The landscape will be taken with a normal lens, the moon taken with a telephoto lens, to get a bigger image.\n\nHow does this illusion come about? Since the moon always subtends an angle of 0.5 degrees, the image on the retina must always be the same. Clearly the problem is one of interpretation. One simple experiment shows this to be so. A full moon just above the horizon will not appear so large to the human eye if a piece of paper is held up to that eye with a hole in it, so that only the moon can be seen through the hole and not the horizon. If the other eye is open at the same time, viewing both the moon and the horizon, the two eyes will each see different sized moons!\n\nThe explanation is believed to be as follows. We 'know' that a cloud that is overhead will be larger than when it moves towards the horizon. And an airplane that is a mere speck on the horizon becomes large when it is overhead. And we are all familiar with standing under a tree which seems enormous, yet at a couple of hundred paces seems insignificant. It would seem that so much of our world is interpreted this way that we are ill-equipped to cope with an object like the moon, that subtends the same angle at the eye, whatever position it occupies in the sky. And so our brain 'interprets' the image that it 'sees', and tells us that the moon is larger than it really is.\n\nHendrik Ball\n\n\n\nFrom: http://www.straightdope.com/classics/a2_110.html\n\n\nDear Cecil:\n\nI have noticed that the moon (and the sun, for that matter) appears very large just as it rises and sets. When it is overhead, it seems tiny by comparison. The color is also vastly different, but this can be easily explained by the fact that we view the moon through varying ''thicknesses'' of atmosphere as it makes its way across the sky. But this explanation seems insufficient to account for the change in size. So what's the straight dope? --Frank M., Los Angeles\n\nCecil replies:\n\nBelieve it or not, Frank, they've been arguing about this for two thousand years, and it's about time I got things straightened out. First of all, let me make it clear that the effect is an optical illusion. If you measure the moon with a ruler held at arm's length (a paper clip bent into the shape of a calipers will also work), you'll find it's always the same size no matter where it happens to be in the sky. If anything, the moon is slightly smaller at the horizon than it is at the zenith, mainly because it's 4,000 miles (the radius of the earth) farther away. (If you don't understand why this is so, draw yourself a picture.) Nonetheless, most people are convinced that, area-wise, the moon's at least twice as big when it's near the horizon as when it's overhead.\n\nNumerous theories have been advanced to explain the ""moon illusion.'' At one point people thought it had something to do with the angle at which you hold you
299559
As the Moon moves along its orbit around the Earth its hemisphere toward the sun is fully illuminated.\n\nBut from the Earth we see only the hemisphere that is turned toward us.\n\nThat is, we are not seeing that hemisphere which is fully illuminated by the Sun.\n\nThat is why we see different shapes which are called phases of the moon.\n\nIn new moon day, the moon is in between Sun and Earth, and the moon’s non illuminated hemisphere is toward Earth and in the back ground of Sun’s bright light, the moon is invisible.\n\nWhen Moon is at 90 degree from the Sun, half of the illuminated hemisphere of Moon is visible from Earth. \n \nWhen Moon is at 180 degree from the Sun, full of the illuminated hemisphere of Moon is visible from Earth. We call it as Full Moon.
882017
No one who has answered so far got it right.  The answer is TRUE, and the reason is because the moon rotates on its axis in exactly the same amount of time it takes it to make one revolution around the earth.  No one seems to get this.
1023489
No.  But we see only the side that faces earth.\n\nHere's a good diagram that explains it better than I can...\n\n\nhttp://www.windows.ucar.edu/tour/link=/the_universe/uts/moon2.html
330323
what? I don't think the moon appears stationary since it travels across the sky and goes through phases.\nWhat?
1038744
The moon is only visible because the Sun light reflects off of it. Even if the Sun is in the sky at the  same time, we will see it. The Moon circles the Earth every 28 days. While the Earth rotates once every 24 hours. The result is that the Moon seems to change position in the sky by 1/28 of a full rotation every day. During that cycle, the Sun and Moon will be in the daytime sky at least half the time. Sometimes we don't notice the Moon because it is only a small wedge or the clouds hide it. \nBy the way, Venus is also visible during daylight hours during some of it's rotation,  but it is a very tiny  pinpoint of light and is very hard to locate even if it is bright.
969774
Think of it this way.  The earth has 4 sides, just because ONE OF THEM is looking at the moon and the Sun is facing another side, means nothing.  There is over 90,000,000 miles between the earth and the sun, so we only get a fraction of a percent of its total output of energy.  The Moon while it is in space going around us, is no longer "blocked" by the earth and can now receive its share of light from the sun.  HOWEVER, you may be surprised to learn that the albedo (reflection of light) from the moon is mostly caused by the Earth as much as the Sun.  That is, where it is now daylight on Earth is relecting off of the moon also.
711962
probably because it takes the same time for the Moon to rotate around its axis (a day) and orbit the Earth (a year) \nit is always facing the same side because it rotates in conjunction with its orbit (bit hard to explain)\nbecause it is also rotating at the same time, we always see the same side of the Moon
1126649
Yes, everything's upside down from down under!\n\nIf you're facing south looking at an early crescent setting in the northern hemisphere, the Moon is on your right, and the Sun is further to the right (west), so the right (west) side of the Moon is illuminated.  From the southern hemisphere, you're facing north, and west is on your left.  The western side of the Moon is still illuminated, but now you see it on the left. The Moon, of course, appears upside down.
830404
The moon is often visible during the daytime! If it's not visible during the daytime where you are, it's visible from somewhere else on Earth.
236149
The moon spins about an axis. The axis is almost perpendicular to the plane of the moons orbit around the earth. The period of spin (time to complete one rotation about the spin axis) is equal to the period of one revolution around the earth.\n\nThe result is we see one side of the moon.\n\nFor many people this answer is not suffice to understand.\nImagine a cubical building in a plain ground. The four vertical walls are marked A,B,C,D. Imagine the building to be the moon and we are standing infront of the wall marked A. Let us go round the building to see the other walls in the order of ABCD. When we have finished quarter round we can have the full view of the wall B. But imagine that the building rotates itself such that when we finished quarter round it also has rotated quarter round about itself. We will see only the wall A. If the things continue like this we can never see the other walls.When we complete one round the building completes one round so always we see only the wall A.\nDue to librations actually we can see 59% of the moon instead of 50%