MoonEarth

MoonEarth is a coined name used to refer to a hypothetical world or fictional setting in which an Earth-like planet and a substantial natural satellite exist in a closely coupled system. The term emphasizes the interdependent evolution of the planet’s geology, atmosphere, and tidal regime due to the moon’s gravitational influence.

In scientific discussion, MoonEarth is used as a thought experiment to study tidal locking timescales, orbital resonances, and climate stability on a planet with a large satellite.

In science fiction and worldbuilding, MoonEarth appears as a setting where the moon is large relative to the planet, producing strong tides, visible lunar cycles, and potential for tidal heating of oceans or crust.

See also Earth, Moon, binary planet, tidal locking, habitability.