1. Learn about lunar eclipses
Solar and lunar eclipses can happen when the Sun, Moon, and Earth line up in certain ways. Lunar eclipses can only happen during a full moon – in other words when the Moon and Sun are on opposite sides of Earth. When sunlight reaches Earth, a shadow is cast on the side of Earth opposite from the Sun. If the Moon passes through this shadow, it results in a lunar eclipse.
But just because a lunar eclipse can happen during a full moon doesn't mean it will. This is because the Moon's orbit is slightly tilted. So usually, the Moon passes above or below Earth's shadow rather than through it.
The time period when the Moon, Earth, and Sun are lined up and on the same plane – allowing for the Moon to pass through Earth’s shadow – is called an eclipse season. When a full moon occurs during an eclipse season, the Moon travels through Earth’s shadow, creating a lunar eclipse.
Unlike solar eclipses, which require special glasses to view and can be seen only for a few short minutes in a very limited area, a total lunar eclipse can be seen for up to an hour by anyone on the nighttime side of Earth – as long as skies are clear.