Eclipses glossary
What is a partial lunar eclipse?
Partial Lunar Eclipse is a lunar eclipse in which part, but not all, of the Moon enters Earth's umbra.
What it means
Partial Lunar Eclipse is part of eclipse geometry and timing. Eclipses require the Sun, Earth, and Moon to align near the points where the Moon's tilted orbit crosses the ecliptic. That tilt is why an eclipse does not occur at every new or full Moon.
For a deeper look with practical observing advice, read the Moonrise Moment guide to partial lunar eclipse.
Sources and further reading
This definition was written in plain language and checked against these science references.