Roche limit

The Roche limit refers to the critical distance within which celestial bodies, like Saturn's rings, would disintegrate due to tidal forces rather than accrete into a larger body due to gravitational attraction. This concept explains why certain astronomical bodies form rings instead of coalescing into moons or planets.
 Edouard Roche France 1849 Roche limit

The Roche limit refers to the critical distance within which celestial bodies, like Saturn's rings, would disintegrate due to tidal forces rather than accrete into a larger body due to gravitational attraction. This concept explains why certain astronomical bodies form rings instead of coalescing into moons or planets.