The sky could look a little red in the overnight hours as a blood moon casts a crimson color over the United States. The moon going into Friday morning will undergo a rare total lunar eclipse, which is when the sun,

Earth’s shadow will block most of the light that illuminates the lunar surface, creating what is known as a blood moon.

Skywatchers across the world will witness the first total lunar eclipse in three years. Here’s who will have the best views—and what gives the moon its eerie red tint.