The sixth planet

One way into astronomy for a lot of people, I suspect, is the beauty of the planet Saturn, second largest planet in our system (95 times the mass of the Earth). NASA's Cassini space probe, still orbiting the planet, has sent back a multitude of extraordinary photos that show us this gem of the solar system in close up. Other planets have rings, but these are simply spectacular, and visible from Earth through even a small telescope. Made largely of ice, some of it vented through giant geysers from the moon Enceladus, their complexity is still not completely understood. Even less understood is the hexagonal cloud formation around the Saturnian north pole. (It is a bit like finding a big "6" painted on the side of the sixth planet.) No doubt it has a simple explanation (here is one attempt), and probably isn't a marker left by some alien civilization, but in the meantime, just like those "faster than light" neutrinos from Gran Sasso, not to mention the hunt for the Higgs boson which is the lynchpin of the Standard Model of particle physics, it will continue to intrigue us, and to entice a new generation of children into the study of science. Modern physics and cosmology are at a turning point, it seems. The need to explain the "dark matter" and "dark energy" that apparently make up up most of the universe may be pointing to the need for a new "paradigm" or a radically new set of cosmological theories. More than ever, scientists need imagination as well as intelligence, and faith (in the ultimate intelligibility of the universe) as well as reason.