I was travelling at over 5000 km/s by the time I reached the second-largest planet in the solar system. Saturn was immense, and the rings were at close to maximum inclination. The horizontal bands of cloud circling Saturn’s visible surface weren’t as distinctive as those of Jupiter, but each band was wider than the Earth. From this distance I could see lightning flashes from storms that must have been tens of thousands of miles across. Swirls and eddies at the boundaries were literally big enough to drop the moon into. The shadow of the rings fell across the planet, and I could see that it wasn’t just a flat surface—the shadow dipped and bent as it lay across different levels and layers of cloud. I remembered all the science fiction books I’d read that had whole ecosystems floating around in the different layers, and I wondered if I’d find anything like that in my travels.