Why the Moon Turns Blood Red

During a total lunar eclipse, the moon does not go dark but instead glows a deep, blood red. This happens because Earths atmosphere scatters sunlight, filtering out blue light while projecting red light onto the lunar surface.

Imagine the Earth acting like a massive lens. As sunlight passes through our atmosphere, the air particles scatter away the shorter blue wavelengths, leaving only the longer red wavelengths to pass through. These red rays are then bent around the Earth by refraction and projected onto the moon. Because of this, a lunar eclipse is essentially the combined light of every sunrise and sunset happening on Earth at that exact moment. It is a stunning visual reminder of the atmosphere that protects our planet.