The Moon has four phases : new, rising, full and waning. Each lasts about 7 to 8 days.
Not being a star, the moon does not emit its own light. However, we see it illuminated because it reflects light from the sun.
The moon has three main movements: rotation (around its own axis), revolution (around the earth) and translation (around the sun, along with the earth).
In this way, it assumes different positions relative to the Earth and the Sun. This makes its illuminated part seen in different ways along a lunar cycle.
It is therefore known as the lunar month and during this period the 4 phases of the moon happen, that is, the complete lunar cycle occurs.
Already in the Sidereal Period the time it takes for the moon to rotate around its axis (rotation) is 27.3 days and this is also the time it takes to orbit around its axis. Earth (revolution).
Therefore, the sidereal month is considered approximately 2.25 days shorter than the synodic month.
The video produced by NASA shows the phases of the moon at one-hour intervals throughout 2018, as seen from the southern hemisphere.
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