Why Blood Moon turns red during a total lunar eclipse
By Kiprono Keileb, September 7, 2025Every now and then, the night sky treats us to a magical sight: the Blood Moon. During a total lunar eclipse, the moon glows in a rich, reddish hue, leaving stargazers in awe. But why does this happen, and what makes the Blood Moon so mesmerising?
A total lunar eclipse occurs when the Earth moves directly between the Sun and the Moon. This means that the Moon no longer receives direct sunlight. Instead of vanishing into darkness, the Moon takes on a warm red or coppery glow. The secret lies in the Earth’s atmosphere and the way it bends sunlight.
As sunlight passes through our atmosphere, the shorter, bluer wavelengths scatter into space; this is why our sky appears blue during the day. The longer, red and orange wavelengths, however, bend around the Earth and gently fall on the Moon, giving it that striking colour. This natural effect, known as Rayleigh scattering, turns the lunar surface into the iconic Blood Moon we admire.
The shade of red you see can vary. Volcanic ash, dust storms, or smoke in the atmosphere can make the Moon appear darker, almost copper-red. On clear nights, the Moon can glow with a brighter, softer red. Each Blood Moon is therefore unique, a reflection of both the sky above and the world below.
For centuries, people have looked to the Blood Moon with wonder. Ancient cultures saw it as mysterious or symbolic. Some tied it to important events or spiritual meanings, while others simply enjoyed its beauty. Today, we may understand the science behind it, yet it still inspires the same sense of awe and connection to the cosmos.
If you want to experience a Blood Moon, timing is everything. The eclipse can last several hours, with totality, the time when the Moon is fully in Earth’s shadow, lasting anywhere from a few minutes to over an hour. Find a spot with clear skies, away from bright city lights, and you’ll see the Moon bathed in its reddish glow. Even a simple pair of binoculars can make the view unforgettable.
The Blood Moon reminds us of the delicate balance between our planet, its atmosphere, and the wider universe. Each appearance is a gentle invitation to pause, look up, and marvel at the natural beauty of the world above.