How rare is tonight’s blood moon? Lunar eclipses are less common than solar eclipses, with a maximum of three occurring in any given location per year, though some years there can be none. However, each lunar eclipse is visible from more than half the Earth.
If this eclipse is rare, it is because it will last for so long. The moon will be in the Earth’s shadow for four hours and totally eclipsed for one hour and 43 minutes, which is just short of the theoretical limit of a lunar eclipse (one hour and 47 minutes). The eclipse will last for so long on Friday night/Saturday morning because the moon will be passing through the centre of the Earth’s shadow