What are the different phases of the Moon and why do they happen?

The phases of the Moon are defined in astronomy as the visible portion of the Moon as seen from the Earth on any given night. The lunar phases occur in cycles as the Moon orbits the Earth. The Moon appears visibly "lit up" because of the Sun's reflected light. Because only half the Moon faces the Sun at any one time, only half the Moon is visible from the Earth.

Since the Moon moves around the Earth, we see the visibly lit portion of the Moon at different angles on the Earth, this is what causes the different phases of the Moon. As the positions of the Earth, the Sun, and the Moon change in relation to each other, the Moon phases also change.

The different Moon phases are as follows:

• Dark Moon - Not visible
• New Moon - Not visible
• Waxing Crescent Moon - Right 1-49% visible
• First Quarter Moon - Right 50% visible
• Waxing gibbous Moon - Right 51-99% visible
• Full Moon - Fully visible
• Waning gibbous Moon - 51-99% visible
• Third Quarter Moon - Left 50% visible
• Waning Crescent Moon - Left 1-49% visible
• New Moon - Not visible

  Whenever the Moon and the Sun happen to be on opposite sides of the Earth, the Moon looks like it's full. As the Moon moves around the Earth, the lighted portion of the Moon changes. Whenever the Moon is between the Earth and the Sun, the Moon isn't visible.

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