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.

As the moon reflects the sun's light, the shadow dims the moon's glow. During the peak of a total lunar eclipse, the moon takes on a bit of a reddish hue as any leftover sunlight making it to the moon's surface is scattered by our earth's atmosphere.