when does the moon turn red

The moon turns red during a total lunar eclipse, often referred to as a "Blood Moon." This phenomenon occurs when the Earth is positioned directly between the Sun and the Moon, casting Earth's shadow on the lunar surface. The moon turns red because while Earth's shadow blocks most of the direct sunlight, some sunlight passes through Earth's atmosphere and is refracted onto the Moon. Earth's atmosphere filters out most of the blue light and allows the longer wavelengths of red light to pass through, bathing the Moon in a reddish or coppery hue. The exact shade can vary depending on Earth's atmospheric conditions, such as dust and clouds. A total lunar eclipse, and thus a red moon, happens only during a full moon when the Sun, Earth, and Moon align closely, usually two to three times a year. During this event, the moon can appear from bright orange to deep red for the duration of the eclipse's totality phase, which can last up to nearly two hours. For example, on September 7-8, 2025, a total lunar eclipse will cause the moon to turn a striking red color for about 82 minutes. This event is visible from large parts of the Eastern Hemisphere, including Asia, Europe, Africa, and Australia.