The phases of the moon are the different forms it takes when viewed from Earth. The light from the moon is reflected light from the sun shining on it, so the phase that we see depends on the position of the Earth, Sun and Moon.
We see a new moon when the moon is between the Earth and Sun and we see the dark side that faces the Earth. We see a full moon when the moon has rotated around so that the whole surface that faces us reflects the sunlight.
The phases inbetween the new moon and the full moon are called the crescent moon, quarter moon, and gibbous moon. They are called waxing when the reflecting light is growing toward the full moon, and waning when it is shrinking to the new moon.
It takes 29.5 days for the moon to make one cycle through its phases.
A lunar eclipse occurs when the moon's path moves into the Earth's shadow.
Now, take our Virtual Tour of the Phases of the Moon!
Below is a Quicktime VR movie. Click on the picture, then use your right or left arrow key to move the picture all the way around (360 degrees).
To learn more about the moon, check out these sites:
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