Why is the lunar eclipse exactly the same size as the sun...covering it perfectly?
439041
The Moon is 400 times smaller than the Sun AND 400 times closer. Why? I don't think there is any real reason, we are just lucky.
477677
Cautious cook is a moron!  The moon, as anyone knows who passed high school physical science, remains the same distance while orbiting around the earth (us).  Also, interesting to note, the rotation of the moon is, in relation to the orbit, the same speed.  Meaning no matter at what part of the orbit, the moon is, we always see, the same side of the moon.  This is known as the light side of the moon.  The only way to see the dark side is to go there.  Apollo did this.  Now, onto your question it is very easily answered.  Just as a lens warps light to make things appear closer or farther away, the atmosphere of the earth is curved causing the same effect towards the horizon.  The reason you don't have this effect when the moon is overhead is because you are looking through less of the atmosphere, and the effect is less prominent.
1122015
A solar eclipse occurs when the Moon passes between the Earth and the Sun, thereby totally or partially obscuring Earth's view of the Sun. If the same thing happens where the moon passes through the earth's shadow, that's called a lunar eclipse.
1041670
The distance to the sun can be computed by a variety of techniques.  Trigonometry and parallax measurements were used by ancient greek and arab astronomers to come up with pretty good estimates for the distances to the sun, moon, and other planets.\n\nThe sun's diameter at its equator is about 865,000 miles, and the mean distance from the earth to the sun is about 93 million miles.\n\nThe moon's diameter at its equator is about 2,160 miles, and the mean distance from the earth to the moon is about 238,900 miles.\n\nThe ratio of the diameters is 865000 / 2160 or about 400.  The ratio of distances is 93,000,000 / 238,900 or about 390.  So the sun is about 400 times larger than the moon, but it's also about 400 times farther away - so the sun and moon appear about the same size in the sky.\n\nThe moon's orbit around the earth isn't a circle, and the lunar distance varies from about 220,000 miles to about 252,000 miles.  When it is close to the earth, the moon appears slightly larger than the sun.  When it is in the further part of it's orbit, the moon appears slightly smaller than the sun.  If an eclipse occurs when the moon is furthest from earth, the moon's disk can't completely cover the sun.  The result is an "annular" eclipse.\n\nIncidentally, the moon gets slightly farther away from the earth every year.  Eventually, in the distant future, it will be too far away to produce a total eclipse of the sun.
668197
It's an optical illusion which is commonly referred to as the "Moon Illusion", meaning it's true for the moon also...\n\nThe most common misconception is that it is because you are unconsciously comparing the Sun to foreground objects like trees and houses, or even the horizon itself, and that makes the Sun look bigger than when it is all alone in the sky. This turns out to be false. As it happens, there are already excellent descriptions of this effect on the web. Probably the best is by Donald Simanek, Professor of Physics at Lock Haven University of Pennsylvania, and another very good one is by Carl Wenning, from the Illinois State University.\n\nI've also see some nonsense about it being because it's seen through a "thicker slice of atmosphere", which if it were true it would make the Sun look smaller!\n\nIn addition, you have probably seen that the rising or setting Moon looks very red. This is the same reason the sky is blue...
462021
It doesn't GET any bigger than it is, it just LOOKS bigger because it really IS nearer\n\nBecause its distance from the earth varies as the orbit is not a circle, as you asssume, but an ellipse (oval).\n\nThe furthest distance from the earth that the moon reaches in any orbit (lunar month) is called the APOGEE and the nearest distance it approaches in that orbit is the PERIGEE.\n\nIn the table below the distances are in kilometres, measured from the centre of the earth to the centre of the moon.\n\nJust gone:\n\nMar 13  APOGEE 406272 km \nMar 28  PERIGEE 359169 km\n\nComing up soon:\n    \nApr  9 APOGEE 405549 km    \nApr 25 PERIGEE 363735 km  \n\nThe earth's orbit round the Sun is an ellipse too, and the nearest distance in any one orbit (year) is called PERIHELION and the furthest distance in that orbit is called APHELION.\n\nHelios is the Greek word for the sun and Peri- and Ap- are prefixes meaning near to and far from. The sun looks correspondingly smaller at aphelion and larger at perihelion.  \n\nSometimes eclipses of the sun are not quite total if the sun is bigger than usual (near or at perihelion) and the moon smaller than usual (near or at apogee).\n\nThere is a more pronounced variation in the distance between Earth and Mars than either the variation in Sun-Earth or Earth-Moon distances. Mars looks a lot brighter and a lot dimmer as a consequence, at these times.\n\nTo visualise why, think of a clock face. The sun is in the middle of the dial. The earth is on the tip of the hour hand and Mars is on the tip of the minute hand. When the time on the clock face is midnight, five past one, ten past two etc earth and Mars are at their closest. When the time on the clock face is 12.33, 1.37, 2.43 etc Earth and Mars are at their furtherst apart, Mars being the radius of an earth orbit plus the radius of a Mars orbit away, beyond the Sun.\n\n(This too-simple model assumes circles not ellipses and assumes that Mars years are twelve Earth years, where in reality Mars years are only about twice an Earth year. But it gives you a general idea.)
1144844
To begin with, we should know that the earth revolves around the sun and the moon revoloves around the earth. When the moon comes in between the earth and the sun and the three are in a straight line, some portion of the earth, which is facing the moon experiences the solar eclipse.\nHowever, when the earth comes in between sun and the moon, then lunar eclipse takes place.( Moon does not have any light of its own, we see it shining because of the sun light. Hence when the sunlight is blocked there is no light for moon to shine and there is lunar eclipse)
823013
It's an optical illusion.  When the Moon is low on the horizon, we can easily compare its size with the size of familiar things like trees and buildings, while when it is high in the sky we can't compare it as easily.\n\nTo prove this to yourself, the next time you see the Moon, hold your pinky finger up at arms length to "cover" the Moon, and you'll notice it covers the Moon quite easily.  Make a mental note of the size of your little finger compared to the size of the Moon.  Now the next time you see the Moon look huge along the horizon, do the pinky thing again, and you'll notice it's really the same size as before.
229761
First, one can't see the entire Moon from Earth; only one side of the Moon faces the Earth directly, this is the near side of the Moon. The far side of the Moon (sometimes innacurately called the dark side of the Moon) always faces away. this behavior is due to tidal lock: http://en.wikipedia.org/wiki/Tidal_lock .\nSecondly, one may not see the near side of the Moon due to atmospheric phenomena. This is trivial.\nThirdly, one may not see the entire near side of the Moon due to the orientation of the Sun with respect to the Moon. The Sun may be shining on some other side of the Moon with respect to our viewing angle on Earth and thus we only see a fraction of the near side lit up by sunlight. To see this graphically, look at the diagram of Moon phases on http://en.wikipedia.org/wiki/Phases_of_the_moon .\nFinally, one may not see the Moon due to a lunar or solar eclipse. This is caused by the Earth's shadow falling on the Moon in the first case and by the Moon blocking the sunlight from falling on the Earth in your region in the second case. These both occur when the Moon, Earth and Sun are approximately in a line. See http://en.wikipedia.org/wiki/Eclipses for diagrams.\nAlso, the Moon may not be visible because it simply has not risen yet. ;)
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/
189228
When the objects (Sun, Moon, Earth) are in a same line. Let's explain it for the following types:-\n1)Solar Eclipse - In this condition, the order is -Sun, Moon, Earth in an exactly straight line. It always takes place on the day of New Moon \n2)Lunar Eclipse- In this condition, the order is Sun, Earth, Moon in a straight line. It always takes place on the day of Full Moon
906326
Parallax.  By coincidence, the Sun is about 400 times as far away as the Moon and also 400 times the diameter, so it appears about the same size.  If I see a total solar eclipse here in NZ, then anywhere else in the world, the Moon won't be directly in front of the Sun.  For instance, the 1999 total eclipse of the Sun started in Nova Scotia.  Before that, it was only visible from space.   The path of totality crossed the Atlantic, Europe, Turkey, the Middle East, Iran, India and then left the surface of the Earth again.
48821
It is an optical illusion.  The moon appears to be larger because you are comparing it to smaller things.  They have taken very careful measurements and determined that, in fact, the moon is the same size no matter where it is in the sky.\n\nThere was a theory for a while that the moon appears larger because objects in general appear larger when you look horizontally at them.  I have to admit I have a soft spot for that theory no matter how hare-brained it may seem.  After all, your heart jumps when you look down (and maybe up?) a long cliff, but you don't get the same effect when you imagine the same situation in a horizontal context.  I've heard this theory was mostly debunked, so I can't seriously suggest it anymore.
543648
Oh no, you've figured out my hoax!!! You busted me, you're right, its not round. Sorry, I get silly sometimes. If you are at a position when the moon passes directly perpendicular to you relative to the sun's position then you will see a perfect half lit moon. you can simulate this with a big right triangle by taking a golf ball or some other ball and placing it at the  90 degree corner and placing a flashlight at one of the other corners pointing directly at the ball. Now line up your sight from the third corner and you should see a perfect half lit ball. :)
287749
SOLAR Eclipse Is When The MOON Is Directly Between The EARTH And SUN (Blocking The Suns Rays From The Earth)
504332
For the most part, it depends on where you are in comparison to the eclipse.  Also, the alignment of the the sun, moon, and earth need to be within a certain amount to create a partial eclipse or a total eclipse.  This is what I've read...I still might be wrong.
974494
Actually the Moon is a rather poor reflector, with only 7% of light hitting it being reflected.  That is defined as an albedo of 7.  Earth by contrast has an albedo of 35, the increase being due to ice caps and clouds being extremely good reflectors.  Since the Earth is about 4 times the size of the Moon, its surface area is about 16 times as great.  With an albedo 5X greater than the Moon's and a surface 16X the Moon's, at comparable distances Earth is 90 times brighter than the Moon.  One deep space probe actually looked back and photographed the two together, and the Moon is barely visible in the original photo.