Early tomorrow morning, people around the globe will have the opportunity to view one of the most spectacular events in the sky, a total lunar eclipse. Here’s a rundown of how to watch this event and why total lunar eclipses are often referred to as “blood moons.”

Last night, all the necessary celestial bodies aligned to create a rather rare total lunar eclipse. With the normal light blocked by the Earth, the Moon turns a red color, earning it the name Blood Moon.