Science
News: Saturn’s majestic rings are the remnants of a
long-vanished moon that was stripped of its icy outer layer
before its rocky heart plunged into the planet, a new theory
proposes. The icy fragments would have encircled the solar
system’s second largest planet as rings and eventually
spalled off small moons of their own that are still there
today, argues Robin Canup, a planetary scientist at the
Southwest Research Institute in Boulder, Colorado. The theory,
which was published online 12 December in
Nature, will be put to the test in 2017, when
NASA’s
Cassini spacecraft finishes its grand tour of Saturn
by making the best measurements yet of the mass of the rings,
writes Alexandra Witze for
Science News. Researchers can use those and other
details to better tease out how the rings evolved over
time.
