Astronomy and Space

Planets and Moons

Why do lunar eclipses happen?

A lunar eclipse occurs only during a full moon when the moon is on one side of Earth, the sun is on the opposite side, and all three bodies are aligned in the same plane. In this alignment Earth blocks the sun’s rays to cast a shadow on the moon. In a total lunar eclipse the moon seems to disappear from the sky when the whole moon passes through the umbra, or total shadow, created by Earth. A total lunar eclipse may last up to one hour and 40 minutes. If only part of the moon enters the umbra, a partial eclipse occurs. A penumbral eclipse takes place if all or part of the moon passes through the penumbra (partial shadow or “shade”) without touching the umbra. It is difficult to detect this type of eclipse from Earth. From the moon one could see that Earth blocked only part of the sun.

When and where will the next ten total lunar eclipses occur?

June 15, 2011 South America, Europe, Africa, Asia, Australia
December 10, 2011 Europe, East Africa, Asia, Australia, Pacific, North America
April 15, 2014 Australia, Pacific, Americas
October 8, 2014 Asia, Australia, Pacific, Americas
April 4, 2015 Asia, Australia, Pacific, Americas
September 28, 2015 East Pacific, Americas, Europe, Africa, West Asia
January 31, 2018 Europe, Africa, Asia, Australia
July 27, 2018 Asia, Australia, Pacific, western North America
January 21, 2019 South America, Europe, Africa, Asia, Australia
May 26, 2021 Asia, Australia, Pacific, Americas


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