SATURN has a celestial swirl: its outermost ring includes a spiral-shaped element that wraps around the planet three times.
The F ring has puzzled scientists since the 1980s, when the Voyager probes began beaming back pictures showing that it has multiple strands on either side of its circular central band or “core”. These strands are sometimes woven into braids and populated by kinks and knots, all caused by gravitational tugs from the nearby small moons Prometheus and Pandora.
Now full images of the F ring from the Cassini probe show the strands are coils of a spiral that sweeps around…
