<P> The lunar phase or phase of the moon is the shape of the illuminated ( sunlit ) portion of the Moon as seen by an observer on Earth . The lunar phases change cyclically as the Moon orbits the Earth , according to the changing positions of the Moon and Sun relative to the Earth . The Moon 's rotation is tidally locked by the Earth 's gravity , therefore the same lunar surface always faces Earth . This face is variously sunlit depending on the position of the Moon in its orbit . Therefore , the portion of this hemisphere that is visible to an observer on Earth can vary from about 100 % ( full moon ) to 0 % ( new moon ) . The lunar terminator is the boundary between the illuminated and darkened hemispheres . Each of the four `` intermediate '' lunar phases ( see below ) is roughly seven days ( ~ 7.4 days ) but this varies slightly due to the elliptical shape of the Moon 's orbit . Aside from some craters near the lunar poles such as Shoemaker , all parts of the Moon see around 14.77 days of sunlight , followed by 14.77 days of `` night '' . ( The side of the Moon facing away from the Earth is sometimes called the `` dark side of the Moon '' , although that is a misnomer . ) </P>
<P> The lunar phase or phase of the moon is the shape of the illuminated ( sunlit ) portion of the Moon as seen by an observer on Earth . The lunar phases change cyclically as the Moon orbits the Earth , according to the changing positions of the Moon and Sun relative to the Earth . The Moon 's rotation is tidally locked by the Earth 's gravity , therefore the same lunar surface always faces Earth . This face is variously sunlit depending on the position of the Moon in its orbit . Therefore , the portion of this hemisphere that is visible to an observer on Earth can vary from about 100 % ( full moon ) to 0 % ( new moon ) . The lunar terminator is the boundary between the illuminated and darkened hemispheres . Each of the four `` intermediate '' lunar phases ( see below ) is roughly seven days ( ~ 7.4 days ) but this varies slightly due to the elliptical shape of the Moon 's orbit . Aside from some craters near the lunar poles such as Shoemaker , all parts of the Moon see around 14.77 days of sunlight , followed by 14.77 days of `` night '' . ( The side of the Moon facing away from the Earth is sometimes called the `` dark side of the Moon '' , although that is a misnomer . ) </P>
what are the phases of the moon made of
what are the phases of the moon made of
face is variously sunlit
face is variously sunlit