Editing Full moon (section)

==Characteristics==
A full moon is often thought of as an event of a full night's duration, although [[lunar phase|its phase]] seen from Earth continuously waxes or wanes, and is full only at the instant when waxing ends and waning begins. For any given location, about half of these maximum full moons may be visible, while the other half occurs during the day, when the full moon is below the horizon. As the Moon's orbit is inclined by 5.145° from the ecliptic, it is not generally perfectly opposite from the Sun during full phase, therefore a full moon is in general not perfectly full except on nights with a [[lunar eclipse]] as the [[Moon]] crosses the ecliptic at opposition from the Sun.

Many [[almanac]]s list full moons not only by date, but also by their exact time, usually in [[Coordinated Universal Time]] (UTC). Typical monthly [[calendar]]s that include lunar phases may be offset by one day when prepared for a different [[time zone]].

The full moon is generally a suboptimal time for [[astronomical observation]] of the Moon because shadows vanish. It is a poor time for other observations because the bright [[moonlight|sunlight reflected]] by the Moon, amplified by the [[opposition surge]], then [[skyglow|outshines]] many stars.

===Moon phases===
There are eight phases of the moon, which vary from partial to full illumination. The moon phases are also called [[lunar phase]]s. These stages have different names that come from its shape and size at each phase. For example, the crescent moon is 'banana' shaped, and the half-moon is D-shaped. When the moon is nearly full, it is called a gibbous moon. The crescent and gibbous moons each last approximately a week.<ref name="auto">{{Cite web |title=What are the names of full moons throughout the year? {{!}} Royal Museums Greenwich |url=https://www.rmg.co.uk/stories/topics/what-are-names-full-moons-throughout-year |access-date=2023-11-28 |website=www.rmg.co.uk}}</ref>

Each phase is also described in accordance to its position on the full 29.5-day cycle. The eight phases of the moon in order:<ref name="auto"/>
* new moon
* waxing crescent moon
* first quarter moon
* waxing gibbous moon
* full moon
* waning gibbous moon
* last quarter moon
* waning crescent moon

===Formula===
The date and approximate time of a specific full moon (assuming a circular orbit) can be calculated from the following equation:<ref>{{Cite book| first = Jean | last = Meeus | date= 1998 | title = Astronomical Algorithms | edition = 2nd |isbn = 0-943396-61-1| chapter = Phases of the Moon | pages = 349–354 | publisher = Willmann-Bell | location = Richmond, Virginia}}</ref>
:<math> d = 20.362000+ 29.530588861 \times N + 102.026 \times 10^{-12} \times N^2</math>
where ''d'' is the number of days since 1 January 2000 00:00:00 in the [[Terrestrial Time]] scale used in astronomical [[Ephemeris|ephemerides]]; for [[Universal Time]] (UT) add the following approximate correction to ''d'':
: <math>-0.000739 - (235 \times 10^{-12})\times N^2</math> days
where ''N'' is the number of full moons since the first full moon of 2000. The true time of a full moon may differ from this approximation by up to about 14.5 hours as a result of the non-circularity of the Moon's orbit.<ref>{{Cite book| last = Meeus | first = Jean | chapter = The Duration of the Lunation |title= More Mathematical Astronomy Morsels | publisher = Willmann-Bell |location=Richmond, Virginia| date = 2002 | pages = 19–31 | isbn = 0-943396-74-3}}</ref> See [[New moon]] for an explanation of the formula and its parameters.

The age and apparent size of the full moon vary in a cycle of just under 14 [[synodic month]]s, which has been referred to as a [[full moon cycle]].

===Lunar eclipses===
When the Moon moves into [[Earth's shadow]], a [[lunar eclipse]] occurs, during which all or part of the Moon's face may appear reddish due to the [[Rayleigh scattering]] of blue wavelengths and the [[atmospheric refraction|refraction]] of [[sunlight]] through [[Atmosphere of Earth|Earth's atmosphere]].<ref>{{cite book |first=P. Kenneth |last=Seidelmann |date=2005 |title=Explanatory Supplement to the Astronomical Almanac |isbn=0-935702-68-7 |chapter=Phases of the Moon |publisher=University Science Books |page=478 |quote=They are the times when the excess of the Moon's apparent geocentric ecliptic longitude λ<sub>M</sub> over the Sun's apparent geocentric ecliptic longitude is 0, 90, 180, or 270 ...}}</ref><ref>{{cite web |title=Celestial Alignment without Lunar Eclipse; from google (full moon earth block sunlight) result 2 |url=http://people.bu.edu/sscruggs/earthandmoon3.html |access-date=19 September 2016 |archive-date=7 October 2016 |archive-url=https://web.archive.org/web/20161007061804/http://people.bu.edu/sscruggs/earthandmoon3.html |url-status=dead }}</ref><ref>{{cite web |title=tilted from the ecliptic by about 5 degrees; from google (full moon earth block sunlight) result 3 |url=http://www2.astro.psu.edu/users/rbc/a1/lec3n.html |access-date=19 September 2016 |archive-url=https://web.archive.org/web/20170628034821/http://www2.astro.psu.edu/users/rbc/a1/lec3n.html |archive-date=28 June 2017 |url-status=dead }}</ref> Lunar eclipses happen only during a full moon and around points on [[orbit of the Moon|its orbit]] where the [[natural satellite|satellite]] may pass through the planet's shadow. A lunar eclipse does not occur every month because the Moon's orbit is [[orbital inclination|inclined]] 5.145° with respect to the [[ecliptic]] plane of Earth; thus, the Moon usually passes north or south of Earth's shadow, which is mostly restricted to this [[plane of reference]]. Lunar eclipses happen only when the full moon occurs around either [[orbital node|node of its orbit]] (ascending or descending). Therefore, a lunar eclipse occurs about every six months, and often two weeks before or after a [[solar eclipse]], which occurs during a [[new moon]] around the opposite node.