What Would Happen If the Moon Disappeared Tomorrow?

If the Moon disappeared, tides would shrink to about a third of their current size, nights would get much darker, and over very long periods Earth's tilt could wobble more, making climates less stable. This is a thought experiment, since nothing could remove the Moon overnight, but each effect is based on how the Moon shapes Earth today.

What would happen to the tides without the Moon?

The Moon drives most of Earth's tides. The Sun also raises tides, at a bit under half the Moon's strength. Without the Moon, only the smaller solar tides would remain, which would change coastal ecosystems that depend on tidal zones.

Would Earth's tilt change without the Moon?

NASA says the Moon's pull stabilises Earth's wobble on its axis, which keeps the climate relatively steady. Earth's axial tilt is about 23.4°. Modelling studies suggest that without the Moon the tilt could swing much more widely over millions of years. The amount is debated: some research finds smaller swings than early estimates did.

How dark would nights be without the Moon?

Every night would be as dark as a new-Moon night. Many animals use moonlight for hunting, navigation or timing reproduction. Some corals, for example, time their spawning to the lunar cycle.

Would days get shorter?

Tidal friction from the Moon slows Earth's spin, and NASA notes the Moon drifts about 3.8 cm farther away each year. Without it, that slowing would mostly stop, though the change in day length would be tiny on a human timescale.

FAQ

Could the Moon actually disappear? No known process could remove it suddenly.

Would we die without the Moon? Not immediately. The effects would build over long timescales.

Is the Moon moving away? Yes, by about 3.8 cm per year, measured with lasers bounced off reflectors left by the Apollo missions.

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Sources

• 01science.nasa.gov/moon/tides/
• 02science.nasa.gov/moon/facts/
• 03en.wikipedia.org/wiki/Axial_tilt
• 04en.wikipedia.org/wiki/Lunar_Laser_Ranging_experiments