 The most extreme cases are Saturn's moon Pan, which orbits within the rings at only 70% of its fluid Roche limit, as well as Neptune's moon Naiad.Naiad's density is unknown, so its precise Roche limit is also unknown, but if its density were below 1100 kg/m³ it would lie at an even smaller fraction of its Roche limit than Pan.Those satellites which have an orbital period shorter than their planet's rotation period experience tidal deceleration, causing a very gradual spiraling in towards the planet.