How it works
This phases of the moon quiz has 36 questions in three sets: the eight phases and their order, why the Moon's shape changes, and eclipses and moon words such as gibbous, harvest moon and earthshine.
Read the full guide
Three sets
Names and order runs from new moon through waxing crescent, first quarter and waxing gibbous to full and back. Why the phases change asks where the Moon, Earth and Sun sit. Eclipses and moon words covers blue moons, earthshine and more.
Northern or southern sky
Questions about which side of the Moon is lit use the Northern Hemisphere view, as the sources do. From the Southern Hemisphere the Moon looks flipped left to right.
- Waxing means growing, waning means shrinking. In the northern sky, a Moon lit on the right is waxing.
- Crescent is less than half lit, gibbous more than half, and a quarter moon looks like a half moon.
Questions and answers
What are the 8 phases of the moon in order?
New moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last (third) quarter and waning crescent, then new moon again. The whole cycle takes about 29.5 days.
What causes the phases of the moon?
Half of the Moon is always lit by the Sun. As the Moon orbits Earth, we see different amounts of that lit half. Earth's shadow causes lunar eclipses, not the phases.
Why is a quarter moon half lit?
Quarter names how far the Moon is around its orbit, a quarter or three quarters of the way, not how much of it looks lit. From Earth we see half of its face lit.