Editing Lunar phase (section)

== Orientation by latitude ==
[[File:Moon phases by latitude.svg|thumb|right|The observed orientation of the Moon at different phases from different latitudes on Earth (the different orientation displayed between the phases at each latitude show merely the extremes of orientation due to [[libration]])]]

In the [[Northern Hemisphere]], if the left side of the Moon is dark, then the bright part is thickening, and the Moon is described as [[wikt:wax|waxing]] (shifting toward full moon). If the right side of the Moon is dark, then the bright part is thinning, and the Moon is described as waning (past full and shifting toward new moon). Assuming that the viewer is in the Northern Hemisphere, the right side of the Moon is the part that is always waxing. (That is, if the right side is dark, the Moon is becoming darker; if the right side is lit, the Moon is getting brighter.)

In the [[Southern Hemisphere]], the Moon is observed from a perspective inverted, or rotated 180°, to that of the Northern and to all of the images in this article, so that the opposite sides appear to wax or wane.

Closer to the [[Equator]], the [[lunar terminator]] will appear horizontal during the morning and evening. Since the above descriptions of the lunar phases only apply at [[middle latitude|middle]] or [[polar regions of Earth|high latitudes]], observers moving towards the [[tropics]] from northern or southern latitudes will see the Moon rotated anti-clockwise or clockwise with respect to the images in this article.

The lunar crescent can open upward or downward, with the "horns" of the crescent pointing up or down, respectively. When the Sun appears above the Moon in the sky, the crescent opens downward; when the Moon is above the Sun, [[wet moon|the crescent opens upward]]. The crescent Moon is most clearly and brightly visible when the Sun is below the horizon, which implies that the Moon must be above the Sun, and the crescent must open upward. This is therefore the orientation in which the crescent Moon is most often seen from the tropics. The waxing and waning crescents look very similar. The waxing crescent appears in the western sky in the evening, and the waning crescent in the eastern sky in the morning.
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