Lunar eclipses occur when Earth's shadow blocks the sun's light, which otherwise reflects off the moon. When Earth completely blocks the sunlight, the moon looks red or orange. A lunar eclipse can last for a few hours.
There are three types — total, partial and penumbral — with the most dramatic being a total lunar eclipse, in which Earth's shadow completely covers the moon.
A lunar eclipse can occur only at full moon. A total lunar eclipse can happen only when the sun, Earth and moon are perfectly lined up — anything less than perfection creates a partial lunar eclipse or no eclipse at all.
Find out when is the next one at Timeanddate.com.