Final answer:
An object can be broken up by a planet's gravity once it passes the Roche limit, which is the distance where a planet's tidal forces can overcome an object's gravitational self-attraction and cause it to disintegrate.
Step-by-step explanation:
An object can be broken up by a planet's gravity once it passes the Roche limit. The Roche limit is the distance within which a celestial body, held together only by its own gravity, will disintegrate due to a second celestial body's tidal forces exceeding the first body's gravitational self-attraction. Inside the Roche limit, the tidal forces of the planet (or other large celestial body) can pull apart the object, leading to its disintegration.
Determining the precise Roche limit involves considering the densities and sizes of both the object and the planet, as well as their distances from each other. For natural satellites, it helps explain why we don't see moons forming or existing too close to their parent planets. Similarly, for artificial satellites and spacecraft, this concept is important to predict potential disruptions in their orbits if they pass too near a planet.