Why in news? The Blood Moon occurred on the night of September 7-8, 2025, and featured one of the longest totality phases of the decade, lasting about 82 minutes.
What Is a Blood Moon?
A blood moon occurs during a total lunar eclipse, when the Earth passes directly between the Sun and the Moon.
The Earth’s shadow (the umbra) completely covers the Moon, but instead of going completely dark, the Moon glows red or copper due to sunlight filtering and scattering through Earth’s atmosphere, a process known as Rayleigh scattering.
The Moon appears red as Earth’s atmosphere scatters blue light and allows red and orange wavelengths to bend and reach the Moon’s surface.
This phenomenon only happens during a full moon when the Sun, Earth, and Moon align perfectly.
Frequency and Visibility
Lunar eclipses occur about twice a year, but total lunar eclipses (blood moons) are less frequent, happening about once every 1–3 years globally.
Only about 4–5 total lunar eclipses are visible from any single location per decade.
The September 2025 blood moon was visible to roughly 77% of the world’s population, especially across Asia, Africa, Europe, and Australia, making it an exceptionally accessible event.