What does the Roche limit describe?

The Roche limit describes the distance within which a celestial body will disintegrate due to tidal forces from a nearby larger body. This concept is essential in understanding how gravitational forces operate in space, particularly when discussing the interactions between planets, moons, and other celestial objects.

When a smaller body, such as a moon, comes within a certain distance of a much larger body, like a planet, the difference in gravitational forces experienced by the smaller body can become so great that it causes the material to break apart. This limit is determined by factors such as the densities of the two bodies and their sizes, which influence the strength of the tidal forces acting on the smaller body.

The Roche limit is particularly relevant when considering the formation of rings around planets. For instance, the rings of Saturn are made up of material that lies within its Roche limit, meaning that any larger moon within that zone would not remain intact but would instead break apart under the shear gravitational forces of Saturn.

In this context, the other options do not pertain correctly to the Roche limit; for instance, nuclear fusion is relevant to stellar processes, stable orbits relate more to orbital mechanics, and a radius of influence around a planet addresses gravitational control rather than the destructive effects of tidal forces