A total solar eclipse darkens the sky over France. On August 21, a total solar eclipse will cross the United States from coast to coast for the first time since 1918. The historic event is expected to draw record crowds, as millions of people will be in or close to the path of totality, where viewers can see the moon completely blot out the sun for more than two minutes. Before the main event, find out how much you know about eclipses, from the science behind the spectacle to the historic and cultural connotations. Learn more about how solar eclipses happen, the four types of eclipses, and how to view the sun safely if you're within the path of totality.
The Aug. 21 eclipse is actually just one of a series of 77 solar eclipses occurring every 18 years and 11 days, known as the Saros Series 145. It began with the eclipse on Jan. 4, 1639. And while this summer's eclipse will only darken the skies for two minutes and 40 seconds, some of the later eclipses in the series will more than double that. Eclipse No. 48 in the series, for instance, will carve a shadowy path across the southeastern United States and treat skygazers to a full six minutes and 59 seconds of daytime darkness. Make sure you reserve a prime viewing spot for June 2, 2486 now.
We live in a special time, at least when it comes to space. On Monday, a total solar eclipse will pass over a 70-mile-wide swath of the United States, stretching from Oregon to South Carolina. But don't take it for granted. We won't always have the chance to experience total solar eclipses from Earth. According to astrophysicist Neil deGrasse Tyson, eventually, we won't be able to see these kinds of total eclipses from Earth at all.
As the first eclipse to pass over the lower 48 US states since 1918, the event is being billed as the "Great American Total Solar Eclipse." It won't technically be be visible from every US state, but the eclipse will follow a diagonal path from northern Oregon, over Kansas, Missouri and Tennessee in the nation's center and head back out to sea through South Carolina. According to Space.com, that puts over 220 million people within a one-day drive of the totality zone -- directly passing over 12 states and catching the edge of an additional two. Even if you do make the trek out, the phenomenon won't last long -- at best, the full eclipse will only last two minutes and forty seconds. Still, if you're looking for an excuse to plan a road trip next year, a once-in-a-lifetime solar eclipse is a pretty good one.
Sky-watchers across the United States are gearing up for the best cosmic spectacle in nearly a century, when a total solar eclipse will race over the entire country for the first time since 1918. On August 21, tens of millions of lucky people will be able to watch the moon completely cover the sun and turn day into night for a few fleeting minutes. The main event will be visible from a relatively narrow path, starting in Oregon and ending in South Carolina. In between, the total eclipse will cross multiple cities in 12 states, prompting plans for countless watch parties, cosmic-themed tours, and scientific observations. While many people will be traveling to be sure they can see the moon fully blot out the sun, viewers in other parts of the U.S., as well as the rest of North America and parts of Central and South America, will get to enjoy a partial eclipse, when the moon appears to take a bite out the sun.