Friday, August 25, 2017

The amazing thing about a total solar eclipse

The thing that has always bugged me about the solar eclipse phenomenon is why the moon appears to be just big enough to exactly cover the sun, leaving only a thin corona peaking out on all sides. The sun and moon are completely different sizes. The sun's diameter is 864,575.9 miles, while the moon's diameter is only 2,159 miles (yes I just googled that). The sun is 400 times bigger than the moon.

I understand that the moon looks like it is about the same size as the sun because it is so much closer to us. But what are the odds that the relative position of the sun and moon when viewed from the Earth would be such that it would almost exactly make up for the huge size difference of the two? If the distances or sizes were just a little different, the moon would not fully cover the sun and we would never have a totality experience, when the world goes dark. Instead, we would just have a dark dot in the center of a bright ring. Or, if the distances or sizes were adjusted in a different direction, an eclipse would completely obscure the sun, with no corona, just darkness.

The chances that the sun and moon's relative size and distance were just right to make the total eclipse experience we get on Earth must have been extremely slight. That is the real miracle of a total eclipse. It is not the fact that, if you wait long enough, sometimes revolving objects line up with each other.