Moon Orbit Simulator
Follow the Moon as it orbits Earth in 3D. Speed up time to watch a full lunar month, and see why the Moon shows phases and why eclipses are rare.
Open the Moon in the simulator →
Moon facts
| Mean radius | 1,737 km |
|---|---|
| Mass | 7.35 × 10²² kg |
| Orbital period around Earth | 27.3 days |
| Average distance from Earth | 384,400 km |
| Synodic month (new Moon to new Moon) | 29.5 days |
Why we see phases
The Moon does not produce its own light — we see the half lit by the Sun. As the Moon orbits Earth, the sunlit fraction we can see changes, giving the cycle from new to full and back. Because the Moon’s orbit is tilted about 5° to Earth’s, the three bodies only line up occasionally, which is why we do not get an eclipse every month.