Editing Lunar eclipse (section)

=== Penumbral lunar eclipse ===
A penumbral lunar eclipse occurs when part or all of the Moon's near side passes into the Earth's penumbra.{{Sfn|Link|1969|p=2}} No part of the moon is in the Earth's umbra during this event, meaning that on all or a part of the Moon's surface facing Earth, the sun is partially blocked. The penumbra causes a subtle dimming of the lunar surface, which is only visible to the naked eye when the majority of the Moon's diameter has immersed into Earth's penumbra.<ref>{{Cite book |last=H. Mucke |first=J. Meeus |title=Canon of Lunar Eclipses -2002 to +2526 |date=1992 |publisher=Astronomisches Büro Wien |edition=3rd |page=V|bibcode=1992cle..book.....M }}</ref> A special type of penumbral eclipse is a ''[[total penumbral lunar eclipse]]'', during which the entire Moon lies exclusively within Earth's penumbra. 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.