when we look the moon rising on the horizon, isn't it optically larger than when it is high in the sky? why?
113023
It is just an optical illusion. Your brain apparently compares the moon (and the sun) with familiar objects around it and that makes it appear larger. If you took pictures and measured, you would see that there is no difference (we had to do this in school in grade 8, and there definitely is no size difference). \n\nThere are refraction effects when the moon and the sun is low in the horizon that distort their shape so they do not look spherical, or are no longer simply connected, or exhibit green flashes etc. But the size does not vary appreciably if they are high enough in the sky to be seen as circular disks.
422854
The moon although is a sphere, but it is so far away that it appear a flat round disk. there is nothing strange about this and if people are not educated that moon is a spherical rock, they'd probably think it's a round flat disk.\n\nBut for me, I see it as a hole in the ceiling.
25058
The so-called "moon illusion" or "moon effect" has perplexed people since earliest historical times, at least as early as the 7th century BCE. It is described in early Greek and Chinese writings. Aristotle mentions it in 350 BCE.\n\nThe moon seems larger in angular size when it is near the horizon than when it is high in the sky. Some people judge it to be as much as twice as large, but the average estimate is 50% to 75% larger.\n\nIt's not a small effect. The Sun displays the same illusion, but viewing the Sun directly with the eye is hazardous without proper precautions, so let's leave that out of this discussion. The same illusion is observed with any extended object in the sky, such as a constellation.
941426
Since the orbital plane of the moon is not the same as the ecliptic, and due to the eath axis or rotation being angled 23 degree, there will be variations as to how far North or South the moon will rise.  But this variation occurs over the course of a year, juts like the seasons.  If you mean "before" like a couple of years ago, then the answer is no.
245326
It's an optical illusion, because you can easily compare it to other objects on the ground when the moon is closer to the ground.
869305
The appearance of the Moon is also dependent on the fact the the Earth is rotating on its axis. Objects appear at the horizon, drift overhead and slip below the horizon again. that is the main reason the Moon looks as it does.\n\n;-D The Moon is romantic! Let's not forget that!
384596
No and Yes.\n\nThe moon is orbiting the Earth more slowly than the Earth is rotating.  It falls behind a little every day.  About 56 minutes behind.  So if tonight the Moon rises over the mountains at 8:00pm, tomorrow it will rise over the mountains at 8:56pm.  (thats the No)\n\nIn pretty much the same place. (There's your Yes)
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.
388414
refraction from the atmosphere magnifies.  When the moon, or sun, is low on the horizon, you're looking through more of the atmosphere to see it.
448771
I think it would because while the sun and the moon both shine, the moon is not boastful and sometimes hides away only showing it's light some of the time and, even then, only softly. Doesn't that seem beautiful to you?
410954
The Earth is round.\nObviously at lower latitudes you view the moon from a different angle than what you would at higher latitudes.\nSo that at the equater the moon when rising would look like a bowl from that angle in that phase.
58227
No.  The moon would alwayd be full if you were on the sun, because the sun's light illuminates the moon.  You would, howvere, be able to see the side of the moon that is never possible to see from the earth (which we incorrectly call "the dark side of the moon").
17267
It is an optical illusion.  The sun is the same size all the time.  When it is at the horizon, you have many things to compare it to.  When it is in the middle of the sky, there is just sky....
1062260
While you could put a big mirror on the Moon to give more sunlight to the Earth, it would not always be there. The Moon is not always in the sky at night. Sometimes you see a full Moon which is up all night and sometimes a crescent Moon that sets a couple hours after the Sun.\nAnyway, why would you want to do that? To increase global warming? To disturb astronomers who need dark skies? To ruin the natural sleeping and waking cycles of animals and people?
379155
The moon looks bigger when it is closer to the horizon. \n\nIt's an optical illusion. Our brain makes the focal point (the farthest point) of a perspective appear larger. If you look at the moon by turning your head upside-down, the moon will appear to be normal size.
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/
1152361
This is an optical illusion caused when the moon is near the horizon.  In angular terms, the moon appears to move with an angular velocity of about 14.5 degrees per hour (15 degrees per hour due to the earth's rotation, minus approx. 1/28 of that to account for the moon's revolution around the earth in what appears to be the opposite direction).\n\nWhen the moon is near the horizon, we perceive it as moving more rapidly because our eyes have the reference point of the earth's surface to compare.\n\nWhen it is high in the sky, there is no convenient reference point on earth nearby. The other stars, etc. also appear to move at about 15 degrees per hour due to the earth's rotation - so the apparent motion of the moon compared to them is much less than the apparent motion with respect to the earth.