Gibbous moon

The Moon makes one complete rotation of the Earth in 29.5 days. During this period, called a lunar month, the Moon goes through 4 phases: the first quarter, the full Moon, the last quarter and the new Moon. The periods between the phases are called the crescent moon and the gibbous moon.

The period between the new Moon and the first quarter is called the waxing crescent moon. From then on, every day the Moon shows a more and more brightly lit surface. After the full Moon when the entire surface of the Moon is lit, the reverse phenomenon occurs up to the last quarter. This is called the waning gibbous Moon. The period between the last quarter and the new Moon is called the waning crescent.