Orbital tilt of the Moon
Why isn’t there an eclipse every month?
The Moon’s orbit is tilted about 5° compared with Earth’s orbit around the Sun. Most months, the Moon passes above or below the alignment needed for an eclipse.
Try the question
Why isn’t there an eclipse every month?
Set the orbit to 0°, then restore its real tilt. Watch the Moon move off the exact Sun–Earth line.
Watch for: Phase controls left–right alignment; orbital tilt controls the missing up–down dimension.
What to look for
Use the model to compare a tilted orbit with a flat orbit. Watch where the Moon passes Earth’s shadow. Does it enter the shadow on every trip?
Questions answered
Does every full moon make a lunar eclipse? No. The Moon usually passes above or below Earth’s shadow.
Does every new moon make a solar eclipse? No. The Moon’s shadow usually misses Earth. Explore upcoming lunar eclipses.
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Where the two paths cross
The flat surface of an orbit is called its plane. The Moon’s orbit crosses Earth’s orbital plane at two places, called nodes. Eclipses can happen when a new or full moon occurs near one of those crossings.
The 5° tilt is different from Earth’s 23.4° axial tilt. One describes an orbit. The other describes how a world spins.
See it live
On the hub: Moon