A lunar eclipse only occurs during a full moon. The phenomenon is observed when the Earth is situated precisely between the Moon and the Sun. In such a situation, the Earth’s shadow falls on the Moon’s surface, which dims or obscures the sunlight that is reflected by the Moon. Sometimes, this dimming or obscuration can cause the Moon to turn slightly red. Lunar eclipses are not as rare as solar eclipses. On a few occasions each year, the Earth, the Moon and the Sun line up in just the right way to create the “shadowplay” that we call an eclipse, according to NASA. There are three different kinds of lunar eclipses—total, partial and penumbral. When the Moon moves into the inner part of the Earth’s shadow, or the umbra, it results in a total solar eclipse. Usually, a total lunar eclipse is when the Moon appears to turn a shade of red. When the Sun, Earth and Moon align imperfectly, and only a portion of the Moon passes through the Earth’s umbra, a partial lunar eclipse is observed. During a penumbral eclipse, the Moon only travels through the Earth’s penumbra, which is the faint outer part of its shadow. Due to this, the Moon dims so slightly that it is easy to miss altogether.