When the Sun, Earth, and Moon line up, the Moon enters shadow of Earth, creating a lunar eclipse. During a total lunar eclipse, the entire Moon is engulfed in the umbra, the region of Earth shadow that is the darkest. Up to 99.1% of the Moon disc will be in the umbra of Earth during this eclipse.
Total, partial, and penumbral lunar eclipses are the three types that can occur.
1. Total Lunar Eclipse - When the entire surface of the Moon is covered by Earth umbra, the dark, centre portion of its shadow, this is known as a total lunar eclipse.
2. Partial Lunar Eclipse - A partial lunar eclipse occurs when umbra of Earth only covers a portion of the Moon surface.
3. Pneumbral Lunar Eclipse - When the Moon passes through the flimsy penumbral region of Earth shadow, a penumbral lunar eclipse occurs.
Why Moon turns Red during Lunar Eclipse ?
The only sunlight that reaches the Moon during a lunar eclipse passes via Earth atmosphere, turning it crimson. The Moon will appear redder during the eclipse if there is more dust or cloud cover in Earth atmosphere. It appears as though the Moon is being projected with all of the world sunrises and sunsets.