The Phases of the Moon

The Moon is the Earth's only natural satellite.
The Moon does not give out light.
It appears as a bright object in the sky at night because it reflects light from the Sun.
If the Moon is observed every night, one can see taht:
-the Moon rises at different times each night.
-the shape of the moon appears to change.
This happens because as the Moon travels in its orbit, the Sun shines on different parts of the Moon.
This makes the appear to change its shape each night.
The different shapes of the Moon we see as it orbits the Earth are known as the phases of the Moon.



A full moon is the lunar phase seen when the whole of the Moon's lit side is facing Earth. This phase happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. At this point, the Moon appears as a half-circle, since only half of the Moon's lit surface is visible from Earth. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase, and we do not usually see the Moon at this point. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the gibbous moon phase, the moon is more than half lit but not full. During the crescent moon phase, the moon is less than half lit and is seen as only a sliver or crescent shape.




It takes about 29.5 days for the Moon to revolve around Earth and go through all the phases.