Sunday, April 25, 2010

Sun and Moon

Have you ever looked up at the sky and noticed that the sun and moon look to be the same size? We... in with our modern science... know that they aren't, but... when you look at them with the naked eye, they do look very similar... particularly if you have a solar eclipse! How does that happen? How is it that the moon is just the right size, and the sun is just the right size... and the distances between the earth and the moon and the sun are all just the right distance, for it all to come together? Kind of cool I think! It turns out that the sun is about 400 times bigger than the moon, but the sun is also about 400 times farther away so... it all works out to... looking the same size. Except, not really. The moon has an ellipitcal orbit around the earth, so sometimes it looks a bit smaller and sometimes a bit bigger, and so sometimes we see more of the sun's corona than at others. Think of all the scientific knowledge we've gained about the sun because we can see solar flares and the corona during an eclipse... Also interesting to note that the moon's orbit is slowly getting bigger (about an inch/year) around the earth, so it's getting slightly farther away. Millions of years ago, the moon would have appeared bigger... and there'd be no solar activity visible... A few million years from now, the moon will appear smaller than the sun... and not total eclipse... Coincidence?? What would your world, our mythology have looked like if we had had a moon that appeared much larger than the sun... or much smaller than the sun? Or if we had had multiple moons? I don't know... just thinking it's kind of cool!

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