If you want to see a total solar eclipse without leaving the United States, Aug. 21, 2017, will be the chance of a lifetime – literally.
This year’s eclipse is special to Americans because its path of totality – the area on the ground from which observers will see the moon completely blocking the sun – will meander across much of the country, from Oregon to South Carolina. Moreover, it will only be visible from the U.S. This has never happened before.
Over the next 100 years, there will be 69 total solar eclipses visible from planet Earth, but only a handful will be visible from North America, according to the Washington Post. The next coast-to-coast total eclipse won’t happen until 2045. So unless you plan to do some serious traveling, or wait another 28 years, this is your best chance to watch the sun wink out.
What exactly am I seeing? A solar eclipse occurs when the moon passes between Earth and the sun. Because the moon is so much closer to us, it appears larger, and can block some or all of our view of the sun. (To give you a sense of scale, our satellites orbit the planet at 22,236 miles above the Equator. The moon is 238,900 miles from Earth — more than 10 times that distance. The sun is 92,960,000 miles away.)
If you watch a solar eclipse from inside the path of totality, the moon will block pretty much all of the sun. People have described the experience as life-changing.
Where will I need to be? The lunar shadow will follow a diagonal path about 60-70 miles wide from Lincoln City, Oregon, to Charleston, S.C. If you are directly in the path of totality, you will experience a total eclipse for a short period of time — from a few seconds to a couple of minutes.
What if I’m not in the path of totality? You won’t see a total eclipse. But the good news is, everyone in the United States will be able to see a partial eclipse! Check the map below to see how much of the sun will be obstructed in your area. You may still be in for a heck of a show.
What do I need to see the eclipse? You must use eclipse glasses or another protective filter to protect your eyes! And no, regular sunglasses are not enough. (Technically, if you are in the path of totality, there will be a brief window when you can safely take off your glasses. But if you’re not sure what you’re doing, please don’t risk it.)
No eclipse glasses? No problem! Here are other ways to safely view the eclipse.
What else do I need to know? The eclipse will fade in and fade out over a period of hours, but the darkest period in any given area will only last a couple minutes at most. So do your homework! Learn the exact times for your area, and check the weather report for clouds.
And last thing: Put down the cell phone. The internet will be full of eclipse photos from NASA and other professionals with multimillion-dollar cameras, so for most of us, our time will be better spent just enjoying this incredible astronomical event.