The Moon is moving away from Earth at about 3.8 centimeters per year. This happens because of tidal interactions between Earth and the Moon. Earth’s rotation transfers energy to the Moon’s orbit. Over billions of years, this distance change adds up. In the distant past, the Moon appeared much larger in the sky. Tides were stronger back then. Days on Earth were also shorter.
The fact matters because it affects Earth’s rotation and tides. The Moon stabilizes Earth’s axial tilt. Changes influence long-term climate patterns.
It also shows planetary systems are dynamic. Orbits evolve over time. Nothing in space is truly fixed.
The Moon was once close enough to appear three times larger than today.
[NASA, nasa.gov]