The shadow of the moon falls on Earth as seen from the International Space Station during the March 29, 2005 solar eclipse. Image credit: NASA / ISS / Expedition 12.

The sights, safety, and science of the great american eclipse

On August 21st, 2017, a total eclipse will hit 14 states. Here’s your guide to everything you need to know.

“…and the Sun has perished out of heaven, and an evil mist hovers over all.”
-Homer’s Odyssey

On Aug. 21, 2017, a total solar eclipse will occur on Earth, traveling across the United States, coast-to-coast, for the first time in 99 years. From about 10 a.m. on the west coast until nearly 3 p.m. on the east coast, the Moon’s shadow will plunge portions of 14 states into total darkness during the day, blocking out the Sun and creating an experience unlike anything else on Earth. Over 12 million people live within the path of totality, and millions more will flock from all over the country and the world to experience this event: the first total solar eclipse over any part of the continental USA since 1979. What should you look for? What are the dangers? And what’s the science behind how they occur? Let’s find out.

An event like a total solar eclipse occurs when the Earth, Moon and Sun are aligned so well that the Moon’s shadow falls on the surface of our planet. Image credit: NASA’s Scientific Visualization Studio.

Normally, the Moon orbits the Earth in a particular plane, and the Moon-Earth system orbits the Sun in a slightly different plane. If all three objects were perfectly aligned, then every new moon would lead…