When you look up at the Moon at night, do you ever wonder how it’s possible you can see it, and why sometimes only part of the Moon can be seen while other times you see the whole Moon? Unlike the Sun, the Moon doesn’t create its own light. The Moon reflects the light from the Sun making it visible at night. One side of the Moon is always facing the Sun and receives light and the other side is always facing away from the Sun and is in darkness. The amount of light we can see reflecting off the Moon all depends on the position of the Moon compared to the Earth and the Sun.
But what are the phases of the moon? The different amounts of the Moon we see at night is called a phase. The Moon travels through eight distinct phases as it travels around the Earth every 29½ days (about one month).
- New Moon = The Moon is between the Sun and the Earth forming a straight line. The dark side of the Moon is completely facing the Earth so it appears completely dark.
- Waxing Crescent Moon = Waxing means increasing and that light is becoming visible. The Moon begins to move out of line as it travels in a circle around the Earth. A small sliver of the lighted side becomes visible from Earth.
- First Quarter Moon = The Moon moves ¼ of the way around the Earth and half of the lighted and half of the dark sides are visible from Earth.
- Waxing Gibbous Moon = Gibbous means more than half full – the Moon is moving further around the Earth, away from the Sun. Most of the lighted side is now visible from Earth.
- Full Moon = The Earth is between the Sun and the Moon, and the entire lighted side faces the Earth.
- Waning Gibbous Moon = Waning means decreasing - the Moon moves out of line and a sliver of the dark side of the Moon becomes visible again.
- Last Quarter Moon = The Moon has move ¾ of the way around the Earth and the other half of each light and dark side is now visible.
- Waning Crescent Moon = The Moon moves closer is moving closer to being in between the Sun and the Earth. Most of the dark side is facing the Earth.
Once the Moon completes one full orbit and returns to its point between the Sun and the Earth and we begin the cycle again with a new Moon - we also begin a new month!