The astronomical event described is a lunar eclipse, wherein the Moon passes through Earth's shadow, transitioning from fully lit to dark and then lit again.
The astronomical event described is a lunar eclipse. A lunar eclipse occurs when the Earth comes directly between the Sun and the Moon, causing the Earth's shadow to be cast on the Moon's surface. The alignment of the Sun, Earth, and Moon during a lunar eclipse is typically in the order of Sun-Earth-Moon, forming a straight line.
The stages of a lunar eclipse include the penumbral phase, where the Moon enters the Earth's penumbral shadow and undergoes a subtle darkening, followed by the partial phase, where a portion of the Moon enters the Earth's umbral shadow, causing a more noticeable darkening. The total phase is the darkest part of the eclipse when the Moon is entirely within the Earth's umbral shadow, often taking on a reddish hue due to Earth's atmosphere bending sunlight onto the Moon.
In the described event, the Moon starting fully lit corresponds to the period before entering the penumbral shadow. The subsequent darkness for about three hours reflects the partial and total phases of the eclipse, with the Moon passing through the Earth's umbral shadow. Finally, the Moon becoming lit again marks the conclusion of the eclipse as it exits the Earth's umbral shadow.