These Stunning Pictures Show The Blood Moon During The Longest Lunar Eclipse Of The Century

Viewers across the globe, except in North and Central America, were treated to a "blood moon" eclipse Friday night in what experts said was the longest lunar eclipse of the 21st century.

A lunar eclipse occurs when the moon passes through Earth's shadow.

Friday's celestial event lasted for nearly four hours with the moon being totally obscured by Earth's shadow for 1 hour, 42 minutes, and 57 seconds, according to the American Astronomical Society. During totality, the moon appeared reddish in color in what's known as the "blood moon" phenomenon where the moon is illuminated by sunlight filtering through Earth's atmosphere.