Editing Lunar phase (section)

{{short description|Shape of the Moon's sunlit portion as viewed from Earth}}
[[File:2025 Moon Phases - Northern Hemisphere - 4K.webm|thumb|300px|The lunar phases and [[libration]]s in 2025 as viewed from the [[Northern Hemisphere]] at hourly intervals, with titles and supplemental graphics]]
[[File:2025 Moon Phases - Southern Hemisphere - 4K.webm|thumb|300px|The lunar phases and [[libration]]s in 2025 as viewed from the [[Southern Hemisphere]] at hourly intervals, with titles and supplemental graphics]]
[[File:Moondrop.jpg|thumb|right|250px|A [[full moon]] sets behind [[San Gorgonio Mountain]] in California on a midsummer's morning.]]

A '''lunar phase''' or '''Moon phase''' is the apparent shape of the [[Moon]]'s directly sunlit portion as viewed from the [[Earth]]. Because the Moon is [[Tidal locking|tidally locked]] with the Earth, the same [[Hemisphere (geometry)|hemisphere]] is always facing the Earth. In common usage, the four major phases are the [[new moon]], the first quarter, the [[full moon]] and the last quarter; the four minor phases are waxing crescent, waxing gibbous, waning gibbous, and waning crescent. A [[lunar month]] is the time between successive recurrences of the same phase: due to the [[Orbital eccentricity|eccentricity]] of the Moon's orbit, this duration is not perfectly constant but averages about 29.5 days.

The appearance of the Moon (its phase) gradually changes over a lunar month as the relative orbital positions of the Moon around Earth, and Earth around the Sun, shift. The visible side of the Moon is sunlit to varying extents, depending on the position of the Moon in its orbit, with the sunlit portion varying from 0% (at new moon) to nearly 100% (at full moon).<ref>{{cite web |title=Is the 'full moon' merely a fallacy? |website=[[NBC News]] |date=28 February 2004 |url=https://www.nbcnews.com/id/wbna4402294 |access-date=2023-05-30 |language=en}}</ref>