The night sky of 7th & 8th September put on a breathtaking display yesterday, as the Moon transformed into a striking shade of red during the total lunar eclipse. The spectacle, often referred to as a “Blood Moon,” left skywatchers around the world captivated, but the reason behind this celestial glow is rooted firmly in science.

A total lunar eclipse occurs when Earth moves directly between the Sun and the Moon, casting its deepest shadow, known as the umbra, over the lunar surface. At this point, the Moon should logically vanish into darkness. Instead, it glows with a copper or crimson hue. This happens because sunlight isn’t blocked entirely, it filters through Earth’s atmosphere first.

As the light passes through, shorter wavelengths such as blue are scattered away, while longer red and orange wavelengths bend around the planet and continue on to illuminate the Moon. This process, called Rayleigh scattering, is the same reason our skies appear blue by day and sunsets turn fiery in the evening.

The exact shade of red depends heavily on conditions in Earth’s atmosphere. Dust, clouds, pollution, or even volcanic ash can deepen the tone, turning the Moon anywhere from pale orange to blood red. Last night’s eclipse lasted over 80 minutes, making it one of the longest in recent years and visible to billions across the Eastern Hemisphere.

What people witnessed was not magic, but rather a dramatic reminder of how Earth and its atmosphere shape the universe we see. For a few hours, the Moon became the canvas for Earth’s very own sunset, projected across space.