A penumbral lunar eclipse occurs when the Moon passes through penumbra region of the Earth′s shadow. The penumbra causes a subtle dimming of the lunar surface, which is only visible to the naked eye when about seventy percent of the Moon has immersed into Earth′s penumbra.

A special type of penumbral eclipse is a total penumbral lunar eclipse, during which the Moon lies exclusively within the penumbra region of Earth′s shadow. Total penumbral eclipses are rare, and when these occur, the portion of the Moon closest to the umbra may appear slightly darker than the rest of the lunar disk.