this can be seen clearly during the time of solar (also lunar) eclipse when the moon perfectly eclipses the sun...
2007-03-17 16:25:52 · 15 answers · asked by Sudhakar A 1 in Science & Mathematics ➔ Astronomy & Space
It's only a coincidence!
The sun and moon's apparent diameter do change slightly as the earth reaches its nearest and furthest points from the sun while orbiting the sun, and the moon reaches its nearest and furthest points from the earth while orbiting the earth, although the difference is not great. This is why a solar eclipse can be total, when the moon completely obscures the sun, or annular, when it is not quite big enough and leaves a ring visible.
The average apparent diameter of the sun is currently just a little tiny bit bigger than that of the moon, and the day when the two averages were exactly the same has passed. The sun has increased in size (though not by much) since it formed, and will continue to do so for the next few billion years, and the moon is receding from the earth by about an inch per year. Some day, probably within a billion years or so, the last total solar eclipse will occur, and all will be partial or annular afterward.
F.Y.I.: Lunar eclipses are when the earth's shadow falls on the moon and doesn't really belong in this question!
2007-03-17 16:36:00 · answer #1 · answered by Rochester 4 · 1⤊ 0⤋
Sun And Moon Same Size
2016-12-17 14:02:12 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Due to an uncanny coincidence, the Moon and Sun appear in our sky to be exactly the same size .
They subtend the same angle. The sun is far larger, but much farther. It is a strange coincidence, and was not always true: the moon is receding, so appears smaller with time.
they apear the same in size because of two reasons. The first is that things that are farther away look smaller. You can test this by holding up your thumb and blocking the entire moon with just the tip.
The second is that our eyes are not very accurate when comparing relative sizes of things.
2007-03-17 18:14:39 · answer #3 · answered by spaceprt 5 · 1⤊ 0⤋
The Sun is 400 times larger than the Moon and 400 times more distant. This is approximate, not perfect. Some eclipses are annular -- the disc of the Moon cannot completely cover the disk of the Sun.
2007-03-17 16:32:02 · answer #4 · answered by novangelis 7 · 0⤊ 0⤋
Even Astronomers can get confused with these answers.
The size of the sun is the same times larger than the moon, as the distance to the sun from earth is compared to distance of the moon.
sun distance / moon distance = sun size/ moon size
The fact that the sizes of sun and moon are changing, since this will not be of any consequence in our lifetime, does not come into the equation.
The fact that the moon's distance from us varies is the reason that "annular" eclipses take place, not because the moon is receeding.
2007-03-18 00:56:52 · answer #5 · answered by orion_1812@yahoo.com 6 · 0⤊ 1⤋
That's because the moon is MUCH closer to us than the Sun is. Suppose you were the size of a pinhead on a baseball; the moon is a marble and the sun around the size of a soccer ball. The moon happens to be close enough in orbit just to obscure most of the sun (roughly 90%: that ring of light happens to be the unobscured 10% of the sun's luminescence during an total eclipse.
2016-03-18 05:09:38 · answer #6 · answered by Anonymous · 0⤊ 0⤋
For two reasons. The first is that things that are farther away look smaller. You can test this by holding up your thumb and blocking the entire moon with just the tip.
The second is that our eyes are not very accurate when comparing relative sizes of things. So, although the moon and sun relationship is modified by where the earth is in its orbit, our eyes are not accurate enough to detect this difference. As long as the moon is within several tens of thousands of miles from where it is now, it will still appear to us to be 'the same size'. You can test this by guessing a distant person's actual height (when you have no known reference point of comparison). You will find it is nearly impossible to guess within a half foot of their true height, because your eyes are not very good measuring devices.
2007-03-17 16:32:22 · answer #7 · answered by xaviar_onasis 5 · 0⤊ 0⤋
They subtend the same angle. The sun is far larger, but much farther. It is a strange coincidence, and was not always true: the moon is receding, so appears smaller with time.
Are there any other planets for which a moon subtends the same arc as the sun?
2007-03-17 16:30:51 · answer #8 · answered by Anonymous · 2⤊ 0⤋
It is merely a coincidence that the sun is both about 400 times further from us, and about 400 times larger than, the moon.
2007-03-17 16:35:45 · answer #9 · answered by David A 5 · 0⤊ 0⤋
The Sun is huge but 150,000,000 kilometers away, the moon is only 750,000 km away (I think).
2007-03-17 17:06:50 · answer #10 · answered by Anonymous · 0⤊ 0⤋