Solar Eclipse. A Coincidence?

[Cumannach]

Can anybody into astronomy and planetary orbits answer me a question?

Is it just a coincidence that during the Solar eclipse, the moon comes so very close to perfectly blocking out the disc of the sun? I mean, is the radius of the moon in some way related to the radius of it's orbit around the earth, and to the distance of them both from the sun, and related to the radius of the sun making it probable that viewed from the earth the moon when passing between the sun and earth will be very close to being the same size as the sun? But this must all depend on the masses aswell, as well as formation of the orbits and so on...Is it actually a very improbable situation? does it happen with the other planets and their moons?

Can any physicist answer this?

[revolution inaction]

I'v done a degree in physics which included some modules in astronomy, and as far as i know its just coincidence. Several planets have moons but none of them do the same thing, and as far as i know there is no connection between distance from the sun and moon size. The two innermost planets have no moons at all, mars has tine moons, jupiter has four big moons and lots of little ones, saturn has a big moon and several little ones.
The earth has the biggest moon relative to its size and I think the only one that can cause a total eclipse.
The current theory of how it formed is that an object about the size of mars crashed into the earth and the moon formed from the debris ejected.
So as far as i know there's no reason to expect a planet in the position of the earth the have any moon at all, or to say what size it would be if it did have one.
Of cause we only have observations of one solar system to go on, it could be the case that near all planets around other stars in a simile position to the earth have a moon of equivalent size which blocks out the sun just right, and we just don't know the mechanism to cause it yet.

[Oneironaut]

This may be of some interest to you: http://www.historyoftheuniverse.com/tl1.html

[BlackCapital]

http://www.newscientist.com/article/mg20126932.100-why-are-the-sun-and-moon-the-same-size-in-the-sky.html?DCMP=OTC-rss&nsref=online-news

[Iowa656]

The ratio of the moon and suns size just happens to be about the same as the ratio of their distances from Earth. So yeah, just a rather odd coincidence. Or maybe it's proof that aliens exist.... ooooooh.

Just kidding. Read the previously linked New Scientist article. Just a strange coincidence.