Lunar eclipse

A lunar eclipse occurs when the Moon passes into the Earth's shadow, leading to a darkening of its surface. This alignment happens during an eclipse season, which occurs roughly every six months. For a lunar eclipse to take place, it must be during a full moon when the Moon's orbital path intersects closely with the Earth's orbital plane, specifically near one of the two points known as lunar nodes.

The alignment required for a lunar eclipse involves the Sun, Earth, and Moon being in a straight line or very close to it, with the Earth positioned between the Sun and the Moon. This alignment, known as syzygy, occurs only when the Moon is at or near a lunar node during the full moon phase.

The type of lunar eclipse and its duration are influenced by how close the Moon is to the lunar node. A total lunar eclipse, where the Moon is completely covered by Earth's umbra (the central, darkest part of its shadow), results in a "deep eclipse." During such an event, the Moon often takes on a reddish hue. This reddish color happens because, although direct sunlight is blocked by the Earth, some sunlight still reaches the Moon. This light is refracted through the Earth's atmosphere and scatters; shorter blue wavelengths scatter out, leaving longer red wavelengths to illuminate the Moon, a phenomenon known as Rayleigh scattering. This effect also accounts for the orange hues observed in sunrises and sunsets.