In 1855, Maxwell devised a theory that correctly predicted the composition of the rings of Saturn. While at Aberdeen, Maxwell devoted much of his time to the problem and in a letter to Thomson describes the rings as:
“… a great stratum of rubbish jostling and jumbling round Saturn without hope of rest or agreement in itself …”
Maxwell constructed a theory that showed Saturn’s rings couldn’t be solid, liquid or gas, but rather were made of many small, solid, colliding particles orbiting the planet, which were dynamically stable and provided a solid-like appearance; the solution won him the prize. Today, we do know that Saturn’s rings are comprised of tiny rocks that collide with each other as they orbit the planet. In is interesting to note that what led Maxwell to kinetic theory was, oddly enough, Saturn’s rings.