Saturn and its rings form the widest body in the Solar System,
with a total diameter that is three-quarters of the distance
from the Earth to the Moon.
Cassini will track clumps of rock in Saturn's
F-ring, which has a radius of 140,000 kilometres. The ring
may prove to be a useful model for how the planets of our
Solar System formed from smaller chunks of rubble.
"Some recent evidence suggests that they
may actually be quite short lived, and are perhaps only
about 100 million years old," says Andrew Coates, space
scientist at University College London.
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