The moon has many interesting features, like it-s own rotation matching precisely the earths and thus showing us the same face all the time. But one thing I'm not suer is if there is a physical or mathematical reason why the moon eclipses the sun so perfectly (even when it lets a small ring of sun to show), or if it is just a very nice coincidence on it's size and distance from the earth to give us such beautiful events?
2007-11-02 07:29:15 · 7 answers · asked by Ricardo A 3 in Science & Mathematics ➔ Astronomy & Space
Mathematically speaking, the moon is roughly 2000 (2160)miles in diameter while the sun is about 400 times as wide (~866000). The moon is roughly a quarter million miles away while the sun is almost 400 times as far away.
So the moon is smaller and closer than the sun. Their relative distances make each appear to cover about the same area of the sky which is why they appear to be the same size in the sky and why the moon nicely covers the sun in an eclipse.
Because they are not exactly on a scale of 1:400 in size and distance, and because the moon's orbit around the earth and the earth's orbit around the sun are not perfect circles, we sometimes see annular eclipses (when the moon is too "small" to cover the sun and leaves a ring of sunlight), and other times see total eclipses that last from a few seconds to over 7 minutes.
2007-11-02 08:07:15 · answer #1 · answered by David Bowman 7 · 0⤊ 0⤋
Believe it or not, it's strictly a coincidence. The moon just happens to have exactly the right diameter and be at precisely the right distance from us to cause total eclipses.
Hang around awhile though and total eclipses will be a thing of the past because the moon and Earth are very slowly growing farther apart.
2007-11-02 07:34:09 · answer #2 · answered by Anonymous · 4⤊ 0⤋
I think it's a nice coincidence that we see - since it was much closer after it's formation, and will be much further away (and moving an inch or so a year) outward as it's orbiting.
The fact that we only see one face of the moon has to do with it's distribution of mass - it's center of mass isn't in the center of the moon - it's Earth-facing, about 200 miles out from the center, IIRC, causing the moon to be tidally locked.
2007-11-02 08:08:29 · answer #3 · answered by quantumclaustrophobe 7 · 0⤊ 0⤋
It is just an happy coincidence. A couple of billion years ago the moon was closer to the Earth and it would have obscured a lot more of the Sun during an eclipse. But the moon has gradually moved to an higher orbit and now it leaves most of the solar corona visible,
2007-11-02 07:31:43 · answer #4 · answered by Anonymous · 4⤊ 1⤋
The moon eclipses the sun imperfectly. It is oversized compared to the sun in our sight range and the light only lets you see the perfect part of the eclipse.
2007-11-02 07:32:53 · answer #5 · answered by Philip S 4 · 0⤊ 0⤋
Just a very nice coincidence. Certainly no other planet (that we know about) has such a nice setup with any of their Moons.
2007-11-02 08:57:34 · answer #6 · answered by campbelp2002 7 · 0⤊ 0⤋
No mathematical reason.
2007-11-02 08:32:34 · answer #7 · answered by JA 2 · 0⤊ 0⤋