4 Solar Eclipse Facts We Learned From the Reddit AMA With TIME’s Jeffrey Kluger

Ahead of the highly anticipated total solar eclipse that will cross the sky in the U.S. from coast to coast on Aug. 21, 2017, TIME editor-at-large Jeffrey Kluger answered questions from space enthusiasts during a Reddit AMA.

Kluger, who has written about space and science for TIME for more than 20 years, answered questions about the upcoming eclipse, space, science and his career during an hourlong Reddit AMA on Thursday. Here are four things we learned from the session.

When is it OK to look at the total solar eclipse?

“Basically: don’t look at the sun before totality without proper protective glasses,” Kluger advised. “Do look without glasses during totality but put them back on the second even the tiniest part of the sun reappears.”

How can you get kids interested in the solar eclipse?

“If you’re with kids tell them about Baily’s Beads,” Kluger wrote, “the points of light at the last seconds before totality that are the result of the sun streaming through the mountains of the moon.”

Why are total solar eclipses even possible?

“There is no limit to my favorite space facts,” Kluger said on Reddit, “but one of them involves the eclipse: the fact that a perfect total eclipse should not be possible since the sun is 400 times bigger than the moon so there is no way for the coverage to be complete. But the sun is also 400 times farther away, so the disks appear the same size.”

Why are humans so fascinated by the total solar eclipse?

“I think it’s because we’re running cognitive software that was laid down hundreds of thousands of years ago,” Kluger said, “and what we learned back then was that the planet works in certain ways — light during the day, dark at night, phases of the moon come in a particular sequence — and then Boom! One day it all goes screwy. No matter how sophisticated we get, [t]hat rattles us.”

Check out the full Reddit AMA here.