Moon Phases Simulator
Move the Moon around its orbit and see what phase looks like from Earth.
Phase–
Day of cycle0
Lit as seen from Earth0%
Growing or shrinking–
What you can learn
- Half of the Moon is always lit by the Sun. What changes is how much of that lit half faces Earth.
- The full cycle takes about 29.5 days.
- Waxing means the lit part is growing, and waning means it is shrinking.
Frequently asked questions
Is the Moon's shadow from Earth causing the phases?
No. Phases come from our viewing angle of the sunlit half. Earth's shadow only falls on the Moon during a lunar eclipse.
What is the difference between a crescent and a gibbous Moon?
A crescent shows less than half of the disc lit, while a gibbous shows more than half.