01
Distance
The real Earth–Moon distance is about 30 Earth diameters. Here it's compressed so the Moon stays visible next to Earth.
Moon · Question
Why does the Moon change shape?
The Moon does not change shape. What changes is how much of its sunlit half we can see from Earth. Drag the slider below to move the Moon around Earth and watch both views update together.
System view — top-down
What you see from Earth
Full Moon
Drag to move the Moon around Earth. The system view is top-down; sunlight always comes from the left.
29.5 daysOne synodic month — new moon to new moon.
8Named phases in one cycle.
~5°The Moon's orbit is tilted, so eclipses don't happen every month (not shown here).
Same sideThe Moon is tidally locked, so we always see the same face.
What's simplified
This model compresses a few things to stay readable.
Every visualization on Space Atlas states what has been simplified, so a model is never mistaken for the evidence itself.
02
Tilt
The Moon's orbit is tilted about 5° from Earth's orbit around the Sun. This model flattens that tilt, which is also why real eclipses are rarer than this diagram would suggest.
03
Size
Earth and the Moon are enlarged relative to the orbit so both stay clearly visible and clickable-scale.
Misconception check
What most people get wrong about Moon phases.
Quick check
Go deeper
Keep exploring.
Next in this series →
Solar & lunar eclipses ↗
Why eclipses do not happen every month.
Home
Solar system model
See the Moon's home system — the full 3D solar system with all eight planets.
NASA
Eyes on the Solar System
A richer 3D simulation with real mission data and time controls.