Why do Saturn’s rings stay as separate rings instead of becoming one moon?

Saturn’s rings remain as rings because they orbit within the Roche limit, the distance where Saturn’s tidal forces are strong enough to stop loose material from coalescing into a moon. The particles are mostly ice and rock, ranging from dust-sized grains to larger chunks. Small moons and resonances carve gaps, waves, and sharp edges into the ring system. The rings are dynamic, but they are not stable enough to collapse into one object under Saturn’s gravity.