Total solar eclipse? Yes, today. Visible in Seattle? No way.
Total solar eclipse?
Yes, today.
Visible in Seattle? No way.
A solar eclipse is really a game of 3D geometry. The Moon passes between the Sun and Earth, casting its shadow onto a narrow portion of the daylight side of our planet.
Here’s the remarkable part: the Moon is about 400 times smaller in diameter than the Sun, but the Sun is also about 400 times farther away. So from Earth, the two appear nearly the same size in our sky. With just the right alignment, the Moon can completely block the visible disk of the Sun.
The thing is, the Moon’s darkest shadow—the umbra—narrows with distance. By the time it reaches Earth, that shadow can be only a few hundred miles wide or less.
As Earth rotates and the Moon continues along its orbit, that tiny shadow races across the globe, tracing a narrow strip called the path of totality. Today, that path stretches from the Arctic and Greenland through Iceland and into Spain, well outside the view of Western Washington.
It may seem like total solar eclipses have been happening pretty frequently lately. That's because, globally, they really aren't that uncommon. A total solar eclipse occurs somewhere on Earth about once every 18 months, or roughly twice every three years.
But that path of totality is tiny compared with the size of the entire Earth. So for one specific location, totality occurs only about once every 375 years on average.
And Seattle isn't getting lucky next year, either. You'll have to travel to see that one, too!
