what makes the different shapes of the moon
Lunar phase 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.)
Lunar south pole The lunar south pole is located on the center base of the far side of the moon (80°S to 90°S)[3] and covers a distance of about 1250 km.[4] The lunar south pole has shifted 5 degrees from where it previously was billions of years ago. This shift has changed the rotational axis of the moon allowing sunlight to reach areas of the moon previously shadowed. The axis spin is 88.5 degrees from the plane of the elliptic. The south pole contains areas of permanent darkness, where the sunlight never reaches. On the contrary, the pole also contains areas with permanent exposure to sunlight. The south pole contains many craters and basins such as the South Pole-Aitken basin; which appears to be one of the most fundamental features of the moon.[5] The south pole contains mountains such as Epsilon Peak which is taller than any mountain found on earth.[4] The south pole is thermally benign, ranging at an average of 250–270 kelvins.[5]