Watch the Moon across a month and it seems to change shape — a thin crescent, a half, a full glowing circle, then back again. The Moon itself never changes; what changes is how much of its sunlit side we can see from Earth.
The Moon borrows its light
Unlike the Sun, the Moon does not make its own light. It shines only because it reflects sunlight. Half of the Moon is always lit by the Sun — we simply see different amounts of that lit half as the Moon orbits Earth.
The eight phases
- New Moon, Waxing Crescent, First Quarter, Waxing Gibbous,
- Full Moon, Waning Gibbous, Last Quarter, Waning Crescent.
Waxing means the lit part is growing; waning means it is shrinking. One full cycle takes about 29.5 days.
The Moon and tides
The Moon's gravity pulls on Earth's oceans, creating a bulge of water. As Earth spins, coasts move through these bulges, giving us high and low tides roughly twice a day.
🌙 In the Qur'an & Sunnah
The Qur'an describes the Moon with a word for reflected light, nūr, different from the Sun's own light:
"…and the moon a derived/reflected light (nūr) and determined for it phases, that you may know the number of years and the count [of time]…" (Qur'an 10:5)Many Muslims reflect on how the Sun is called ḍiyāʾ (its own light) while the Moon is nūr (reflected) — matching what we now understand. The Qur'an also mentions the Moon's phases returning to a thin curve:
"And the moon — We have determined for it phases, until it returns like the old [curved] date stalk." (Qur'an 36:39)and
"…And made the moon therein a [reflected] light (nūr)…" (Qur'an 71:16)The lunar calendar shapes Muslim worship. The Prophet ﷺ said:
"Fast when you see it [the crescent moon] and break your fast when you see it; and if it is hidden from you, complete thirty days." (Sahih al-Bukhari 1909, Sahih Muslim 1081)So the changing phases you can study scientifically are the very same signs that mark the beginning of Ramadan.
The eight phases, in order
The Moon itself never changes shape. What changes is how much of its sunlit half is turned towards us.
| # | Phase | Growing or shrinking? |
|---|---|---|
| 1 | New Moon | — |
| 2 | Waxing Crescent | Waxing (growing) |
| 3 | First Quarter | Waxing |
| 4 | Waxing Gibbous | Waxing |
| 5 | Full Moon | — |
| 6 | Waning Gibbous | Waning (shrinking) |
| 7 | Last Quarter | Waning |
| 8 | Waning Crescent | Waning |
Waxing means the lit part is growing; waning means it is shrinking. Half the Moon is always lit — we simply see different amounts of it.
Is the lit part growing or shrinking?
- Waxing Crescent
- First Quarter
- Waxing Gibbous
- Waning Gibbous
- Last Quarter
- Waning Crescent