What is a Solar Eclipse?

​​The Earth orbits around the Sun, and it takes about 365 days for the Earth to make the trip all the way around. Meanwhile, the Moon orbits the Earth each 29.5 days, but the Moon orbits on a plane slightly inclined, by five degrees. So sometimes, when the Moon passes directly between the Earth and the Sun, and the three celestial bodies are in syzygy (i.e., perfectly aligned), sunlight is blocked before it can reach the Earth. Depending on how much of the Sun is covered by the Moon, we can see a partial, annular (ring-like) or total solar eclipse.

If you are located in the path of totality of an eclipse, you will see a total solar eclipse. Outside of the path you will observe a partial solar eclipse. Total eclipses are only visible on a small part of the Earth’s surface, weather permitting. The sky must be clear to see the eclipse. If clouds hide the Sun, you will not see it.

A solar eclipse can take place anywhere on the Earth’s surface when the specific conditions of Earth’s rotation and the Moon’s orbit are met. Solar eclipses aren’t uncommon astronomical events, but totality across the United States is, for some, a once-in-a-lifetime event.