This causes its osculating orbital elements to vary with an amplitude of about 20 km (12 mi) in semi-major axis, and 5° in longitude of its periapsis on a timescale of about 450 days.

[12] Methone's smoothness and excellent ellipsoidal fits suggest that it has developed an equipotential surface, and this may be composed largely of an icy fluff, a material that might be mobile enough to explain the moonlet's lack of craters.

[13] Methone's low-density regolith may respond to impacts in a way that smooths its surface more rapidly than on rigid moonlets such as Janus or Epimetheus.

However, in those examples, the thermal anomalies coincide with a distinct UV/IR coloration, which in the case of Methone is either highly subdued or undetectable.

[13] Assuming that Methone is in hydrostatic equilibrium, i.e. that its elongated shape simply reflects the balance between the tidal force exerted by Saturn and Methone's gravity, its density can be estimated: 0.31+0.05−0.03 g/cm3, among the lowest density values obtained or inferred for a Solar System body.