1. Phases of the Moon

2. The phases of the moon are caused by the relative positions of the earth, sun, and moon. The moon goes around the earth, on average, in 27 days 7 hours 43 minutes. The phases of the moon are caused by the relative positions of the earth, sun, and moon. The moon goes around the earth, on average, in 27 days 7 hours 43 minutes.

3. Moon Phases As the moon circles the Earth, the shape of the moon appears to change; this is because different amounts of the illuminated part of the moon are facing us. The shape varies from a full moon (when the Earth is between the sun and the moon) to a new moon (when the moon is between the sun and the Earth). As the moon circles the Earth, the shape of the moon appears to change; this is because different amounts of the illuminated part of the moon are facing us. The shape varies from a full moon (when the Earth is between the sun and the moon) to a new moon (when the moon is between the sun and the Earth).

4. Full Moon A full moon appears as an entire circle in the sky. A full moon appears as an entire circle in the sky.

5. Quarter Moon/Half Moon A half moon looks like half a circle. It is sometimes called a quarter moon. A half moon looks like half a circle. It is sometimes called a quarter moon.

6. Crescent Moon A crescent moon is part way between a half moon and a new moon, or between a new moon and a half moon. A crescent moon is part way between a half moon and a new moon, or between a new moon and a half moon.

7. New Moon The new moon is the phase of the moon when the moon is not visible from Earth, because the side of the moon that is facing us is not being lit by the sun. The new moon is the phase of the moon when the moon is not visible from Earth, because the side of the moon that is facing us is not being lit by the sun.