Phases of the Moon Summary

Phases of the Moon

The moon's phases result from its revolution around the Earth and sunlight reflecting off its surface.
The same side of the moon always faces the Earth due to synchronized rotation and revolution.
The moon takes approximately 27 days to rotate once on its axis and about 29 days to complete one full revolution around the Earth.

New Moon
- Not visible from Earth (moon between Sun and Earth).
- Dark side facing Earth.
- Lasts one night.
Waxing Crescent
- Bright side is increasing, visible as a sliver to almost half.
- Less than half of the moon is illuminated.
First Quarter (Half Moon)
- Entire right side illuminated.
- Appears as a half circle.
- Lasts one night.
Waxing Gibbous
- More than half illuminated but not fully.
- Occurs from the night after the first quarter to the night before the full moon.
Full Moon
- Fully illuminated, appears as a large circle.
- Lasts only one night in a lunation.
Waning Gibbous
- More than half illuminated, decreasing.
- Left side is bright.
Last Quarter (Half Moon)
- Left half illuminated, decreasing.
- Lasts one night.
Waning Crescent
- Less than half illuminated, continuing to shrink in visibility.