Waxing crescent Moon. Optical image of a waxing (increasing in apparent size) crescent Moon. At this stage the Moon is halfway between a new Moon and the first quarter (half Moon). The phases of the Moon (new Moon, first quarter, full Moon and then back to new Moon) are due to its orbit around the Earth. When it lies in between the Earth and the Sun, only the unlit side faces us (new Moon). When the Earth lies between it and the Sun, we see a full Moon. Each cycle takes around 28 days. The lunar hemisphere that faces Earth has bright highlands and dark seas, or maria, which are lowland plains full of dark solidified lava. Several large craters are also seen. Photographed from California, USA, on 22 January 2007.