According to NASA, the phases of the moon are caused by the sunlight and shadow created by its relative position to the sun. At two points during the 29.5-day lunar cycle, the side of the moon facing the Earth is half in sunlight, half in shade. This creates a half moon, a phase that lasts a few days before it either fills to gibbous or shrinks to a waning crescent.Continue Reading
At any given point in time, half of the moon's surface is illuminated by the sun's light. When the illuminated side faces Earth in its entirety, the moon appears full. When the illuminated side faces away from the Earth, the moon is in its new phase. As the moon moves through space around the Earth and its position changes relative to the sun's light, the moon appears to change its phase, beginning as an illuminated crescent after a new moon, swelling to full, and then slowly waning back through a half-moon and waxing crescent before the darkness of the new moon.
In some cases, the Earth's own shadow can cause the face of the moon to change. When the moon and Earth are lined up with the sun, it can create a lunar eclipse. During these events, the Earth's shadow can partially obscure the lit side of the moon, creating a temporary half moon.Learn more about Our Moon
The phases of the moon are caused by the relative positions of the sun, Earth and moon. The moon travels around the Earth, taking just over 29 days to complete a single orbit. The sun illuminates the moon from various angles as it changes position relative to the Earth.Full Answer >
The term "gibbous moon" refers to the phase of the moon's cycle when more than half but less than all of the moon is illuminated by the sun, making it visible from Earth. A gibbous moon can be either waxing or waning, explains Universe Today.Full Answer >
The changing shapes of the moon, known as phases, are actually just changes in perspective from Earth, which appear as a change in the moon's form. From Earth, only one side of the moon ever appears illuminated by the sun, resulting its apparent change in size.Full Answer >
The phases of the moon include the following eight periods: the new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter and waning crescent. According to Starchild, a service within the Astrophysics Science Division at NASA, these phases do not have a definite starting point. However, the phases do occur in a definite order that follows one behind the other.Full Answer >