Why Methone is shaped like an egg

Tides, spin and gravity in balance.

Published 2026-10-23

Methone is a triaxial ellipsoid — all three axes have different lengths.^[1]

Tides

Its longest axis points toward Saturn and is 1.6 times its polar axis. This elongation is caused by tidal forces.^[1]

Spin

Its intermediate axis is 1.07 times the polar axis, caused by centrifugal force from its rotation.^[1]

Equilibrium

Hydrostatic equilibrium is the state where a body’s gravity is balanced by its internal pressure.^[5] Assuming Methone is in this state gives its very low density.^[1]

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