For the first time in 99 years, a total solar eclipse will be visible from coast to coast on Monday, August 21. The last time a total solar eclipse was visible only in the US was in 1776, prompting many to refer to this upcoming event as “The Great American Eclipse.”

The Great American Eclipse will start in the Pacific Ocean, passing through the west coast of Oregon at around 12:05 p.m. ET. and will continue its journey at 1,500 mph all the way through the east coast of South Carolina ending at 4:06 p.m. ET.

Depending on where you are located in the country, the length of the eclipse will vary. According to the verge.com, “The shaded band cutting across the US is the path of totality — which is about 70 miles wide. That’s the area where the Moon’s shadow will track across the planet’s surface, which is the result of the Moon moving on its orbit and the Earth rotating. Anyone within this region will see the Sun completely covered up for a short period of time.”

So, the closer you are to the center red line in the map below, the longer it will be. For those directly located on the red line, the total eclipse will last up to two minutes and 40 seconds. But if you happen to be outside of the path of totality, don’t worry. You’ll still be able to see other phases of the eclipse!

As the moon begins to cover the sun, you’ll be able to see several things. The sun’s light will begin to fade and the moon’s shadow will come into view. You’ll also be able to see “shadow bands” ripple across white walls or white cars. And right before totality, you can catch a phenomenon called Bailey’s Beads, which is the sunlight shining through the craters, peaks, and valleys on the moon’s surface.

During the moments of actual totality, the stars and planets will become brighter and more visible and you will notice a drop in temperature. You’ll be able to experience a 360-degree horizon of sunrise and sunset colors and you may see some animals and plants confuse the darkness for nighttime.

Totality will be the only time you can safely look at the sun without protective eyewear. So make sure you’ve got your pair ready so you can watch The Great American Eclipse’s journey on August 21!