On Monday, millions of people across the U.S. will have the chance to view a total solar eclipse, a celestial event where the Moon lines up with the Sun and blocks its light. Many people who have had the chance to see one from the path of totality describe the event as otherworldly, with the light taking on a new quality. It’s no wonder that these events have held spiritual significance for both ancient people like the Maya and some modern Christians.

As Penn State astronomer Christopher Palma explains, the science behind solar eclipses is pretty spectacular – and coincidental. The Sun is about 400 times larger than the Moon and it’s also 400 times more distant, which means that the Moon can appear about the same size as the Sun when seen from Earth. Add in factors like the tilt of Earth’s orbit, and it makes sense why these events don’t just happen every month.

If you live along the path of totality, which stretches from Texas, across the Midwest and up toward Maine, or you’re traveling to view the eclipse, make sure to bring a pair of certified eclipse glasses. When you look up at the Sun – even if it’s partly covered by the Moon – you can damage your eyes. These glasses help prevent that damage. But watch out for fakes. Some online marketplaces sell phony eclipse glasses that won’t protect you. Supply chain experts Henry Jin of Miami University and Simone Peinkofer from Michigan State recommend checking the brand you get with the American Astronomical Society’s list of approved manufacturers.

You might also want to bring your smartphone to take some pictures. Even if phone cameras aren’t great at capturing the Moon or Sun, photography professor Douglas Goodwin writes that changing a few simple settings can take the photos you snap of your surroundings during the eclipse to the next level. Just remember to take a few moments to put your camera down and take in the event.