The Roche limit , sometimes referred to as the Roche radius , 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 , orbiting material will tend to disperse and form rings , while outside the limit , material will tend to coalesce .
Since tidal forces overwhelm gravity within the Roche limit , no large satellite can coalesce out of smaller particles within that limit .