Moon Phases
Learn about each of the eight primary moon phases — what they look like, when they occur, and how they relate to the Moon–Earth–Sun geometry.
New Moon
A new moon occurs when the Moon is roughly between Earth and the Sun. The sunlit hemisphere faces away from us, so the Moon's disk appears dark — illumination is near 0%.
Waxing Crescent
The waxing crescent is the thin, growing sliver of light that appears after new moon. Illumination rises from a few percent toward first quarter as more of the sunlit face becomes visible.
First Quarter
At first quarter the Moon has completed about one quarter of its orbit since new moon. We see roughly half of the disk lit — the right half in the Northern Hemisphere.
Waxing Gibbous
Waxing gibbous means the Moon is more than half illuminated and still growing toward full. Illumination typically ranges from about 50% to nearly 100%.
Full Moon
A full moon occurs when Earth is roughly between the Sun and the Moon. The entire Earth-facing hemisphere is sunlit — illumination is near 100%.
Waning Gibbous
After full moon the lit fraction begins to shrink. Waning gibbous is still mostly illuminated, typically from nearly 100% down toward 50%.
Last Quarter
Last quarter (also called third quarter) is the half-moon phase after full moon. We see the opposite half lit compared with first quarter — the left half in the Northern Hemisphere.
Waning Crescent
The waning crescent is the thinning sliver that remains before the next new moon. Illumination falls from a modest crescent toward 0%.