Why eclipse

That means during the day, the Moon moves over the Sun and it gets dark. This total eclipse happens about every year and a half somewhere on Earth. A total solar eclipse was visible over the continental United States on Aug. This image was captured in Hopkinsville, Kentucky during the eclipse.

But not everyone experiences every solar eclipse. Getting a chance to see a total solar eclipse is rare. You have to be on the sunny side of the planet when it happens. On average, the same spot on Earth only gets to see a solar eclipse for a few minutes about every years!

Never look directly at the Sun, even for a second! Does this limit eclipses to twice a year? The nodes slowly shift precess westward, which means the months in which eclipses take place slowly change as the years pass. This also affects the type of eclipse that occurs: currently long annulars are more likely in January, long totals in July. Finally, after 6, This is known as the Saros cycle. The Moon is ever so slowly moving away from our planet at rate of about 1. As it recedes, its average apparent diameter shrinks.

And when might this sad prospect come to pass? The area from where you can see the total eclipse is never more than miles wide, and is usually less. This area is not static, because the moon and Earth are not fixed objects: the moon orbits Earth and Earth orbits the sun, in addition to spinning on its axis. This is the path of totality , the only vantage from which you can witness the total eclipse. Although eclipses happen regularly, the path of totality is so extremely limited that very few people have ever seen a total solar eclipse.

If you stood in one place and waited to see one, you could wait for years or more. On August 21, , a total solar eclipse will cross the United States, allowing millions of people to watch it in person.

Find out how to see it. Every day, the same routine. The sun rises in the east. Off to work. Home from work. The sun sets in the west. It's a pattern familiar to everyone on Earth. For countless generations, we've relied on the regular cycles of the heavens to help demarcate our days.