Earlier this month, many people looked up to the sky to catch a glimpse of the blood moon, a total lunar eclipse that gave the moon a deep red glow.

 

While the sight was striking, the science behind it is actually pretty fascinating. Andrew Rogers with the Department of Physics and Astronomy at the University of Manitoba says the colour comes from the way sunlight passes through Earth’s atmosphere during the eclipse.

 

 

Rogers explains that during a total lunar eclipse, the Earth moves directly between the sun and the moon.

 

Most sunlight is blocked, but some light bends through Earth’s atmosphere and reaches the moon — giving it that signature reddish colour.

 

Astronomers say events like this are a great reminder of the way the sun, Earth, and moon all line up in space.