why does the moon appear larger on the horizon than it does in the mid-heaven?
451129
It's all an illusion. The periterrestrial sky has tiny landmarks to make the moon look big. In the higher heaves all you see is sky, which shows the true tiny size of the moon.
280642
It is a coincidence.\n\nThe sun is much larger than the moon (~400 times), and yet the moon is much closer than the sun (~400 times).\nIt is remarkable coincidence that right now, as seen from the Earth, both the moon and the sun appear the same size.\nIt will not stay this way forever, the moon is very slowly moving away from the Earth, eventually it will get far enough away that it will look smaller than the sun and there will be no such thing as a total solar eclipse.
46470
Acutally, the moon's phase isn't tilted, you're tilted.  If you saw the moon early this morning (1/26/06), it was a sliver over in the eastern sky. The bright portion looked like it had rotated counterclockwise. However, it's you, due to the rotation of the earth, that are tilted away from the axis of the moon. If you look at the moon closer to noon, the lighted portion will not appear to be tilted.
830517
The moon goes around the earth faster than we go around the sun...
551537
The line that connects the two points of the crescent Moon is always almost at right angles to the path of the Moon along the sky. If the Moon goes up almost straight from the horizon (as it does when seen from the equator), then the crescent appears horizontal. If the Moon rises at a shallow angle (as seen far from the equator), then it moves as well along the horizon towards the west, and then the crescent is mostly vertical. The Moon rises almost vertically as seen from the equator because the orbit of the Moon stands approximately above the equator.
842966
The tidal forces between the Earth and the Moon slowed the Moon's rotation until it became locked with its orbit around the Earth. The Moon therefore always keeps the same side of its surface facing the Earth. As the Moon orbits the Earth, the entire half facing the sun is illuminated, but the amount of this lighted half that we can see changes. Thus the Moon seems to change shape or phase. The far side of the Moon is lighted part of the time and dark part of the time as well; hence it is incorrect to refer to it as the "dark side of the Moon" (sorry, Pink Floyd).\n\nFor a picture of what the far side of the moon looks like check\nhttp://images.google.com/imgres?imgurl=http://antwrp.gsfc.nasa.gov/apod/image/9810/farside_apollo16.jpg&imgrefurl=http://antwrp.gsfc.nasa.gov/apod/ap981008.html&h=432&w=421&sz=41&hl=en&sig2=9NUu37Lghow0vp6Kt4utAw&start=3&tbnid=zr8LzmzCjXAnwM:&tbnh=126&tbnw=123&ei=y7hmRb_rDbXmwQGpmMHlAQ&prev=/images%3Fq%3Dfar%2Bside%2Bof%2Bthe%2Bmoon%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DG
977400
The moon goes through phases which effect the ways in which it's illuminated as seen from Earth. \n\nAlso, the moon often looks orange and large when it rises or sets for the same reason sunsets are orange, because it is low on the horizon and the light is shining through a lot of the atmosphere so red light  is seen more than other colors, to simplify things greatly.
756100
i would generally say no its not, as the atmosphere is only between 5 adn 10 miles high, the moon is considerably further away than this.\n\ncant explainy why its like this has something to do with the creation of the solar system the mood being far away and such.
291
For those who live in the Northern Hemisphere:\nThe Moon is waxing or waning based on whether the right side of the Moon is dark or light. \n\nThe Moon's lighted area increases over time from right to left. \n\nA good diagram of this can be found at: http://www.astro.umd.edu/education/astro/moon/waxing.gif\n\nFor those who live in the Southern Hemisphere the effect is the opposite.\n\nMore details can be found at: http://www.astro.umd.edu/education/astro/moon/phases.html
539515
Moses and Campbelp have it right--the fluorescent light is closer and of larger apparent size (especially if it is a long tube!).  The sun's shadows are not perfectly sharp because it has some size.  This is the cause of the "penumbral" lunar eclipse, when the moon dims but is not fully eclipsed, as it passes through the dim but not dark portion of the Earth's shadow (the penumbra--the darkest part of a shadow is the umbra).
883973
I think most of the others have it right. The key thing is to remember that the half of the Moon that you can't see is NOT in the Earth's shadow, but it is in the Moon's own shadow. Another way of looking at it is that when we see a "half moon", the people on the moon see a "half Earth". Where is the other half of the Earth? It is in darkness(night time) so you can't see it, but it is still there, isn't it? I hope this helps.
519531
cause it is the moon in front of him
115838
The moon is very far away from the Earth.  It may be hard to imagine, but it is possible to see the moon from many different points on the earth at the same time.\n\nAlso realize that all of Earth experiences the same phase of the moon at the same time.  When we see a full moon, the people on the other side of the world are seeing the same full moon.
407992
No its because the atmosphere acts like a lense. When the moon is high in the sky, the atmosphere has little affect on what the moon looks like so it will be smaller, but as it gets closer and closer to the horizon, you will be looking through a lot more atmosphere, which is like a lense of a magnifying glass. Thats why when it is low in the sky, the moon is very huge looking.\n\nBy the way, just for future reference, all orbits are eliptical because a perfectly circular orbit is only theoretical, and would never occur in nature. However the moon's orbit is close enough to circular to not affect how big it looks compared to the affect the atmosphere does.
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/
30071
Because the rays of light that come from the sun and deflected from the moon go through more of the atmosphere when they're near the horizon and thus, are scattered more throughout, thereby reaching your eyes as a bigger image.
1016790
It's because your mind sees the moon in proportion to landscape features when it is low.  It's kind of an optical illusion - it's not really bigger but your mind interprets it as bigger.