How did Saturn's rings form?
In plain words
If the rings are young, something recently broke up a moon or passing body near Saturn. If old, they formed with the planet, and their icy composition needs another explanation.
Precise statement
Identify the formation mechanism of Saturn's main rings: tidal disruption of a former moon (for example during a satellite-system instability), disruption of a passing body, or primordial formation. An answer is a mechanism reproducing ring mass, ice fraction and the dynamical state of the inner moons.
What would settle it
Dynamical simulations of satellite-system history matching ring mass and composition together with moon orbits and cratering ages.
Status in the literature
Unverified note
2026 proposals (arXiv:2602.09281, arXiv:2603.14088) link young rings to a recent satellite instability or moon stripping.