The Moon goes around Earth, but it usually passes above or below the line between Earth and the Sun. An eclipse needs a closer line-up. That is why eclipses do not happen every month.
Space · Discover & try
Why is there not an eclipse every month?
Reading level 1 of 5 · EarlyChange
Word help
Solar eclipse
The Moon blocking some or all of the Sun’s bright disk from an observer’s view.
Lunar eclipse
An event in which the Moon passes into Earth’s shadow.
Orbital plane
The flat reference surface containing an orbit.
Watch · Try · Explain
See how it works
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A shadow-alignment demonstration; sizes and distances are not to scale. This is not an eclipse calendar.
What to look for
- Compare a new Moon with a solar-eclipse alignment.
- Compare a full Moon with a lunar-eclipse alignment.
- Move the Moon above or below the shadow line.
Explain what you noticed
Why does a full Moon usually avoid Earth’s shadow?
Keep this idea: Eclipses require special alignment; ordinary phases happen throughout the lunar cycle.
Follow the sources
- NASA Space Place — Lunar Eclipses and Solar Eclipses
- NASA — Types of Solar Eclipses
- NASA — Eclipses and the Moon
Source material checked 2026-10-28. Explanations and activities by Nepedia. Agency source links do not imply endorsement.
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