Take a trip to Saturn, the planetary pin-up boy, and not only do you get a ringside seat to the greatest spectacle in the solar system, but a close encounter with two extraordinary moons. Tiny Enceladus is making all the headlines as the must-see moon these days. It's the little moon that has it all: enormous geysers of water and ice shooting into space from the south pole point to a warm salty ocean beneath the surface and, perhaps, a real possibility of life. Even more earth-like and yet far more alien is Titan, with a thick atmosphere and weather. Potentially an easier surface to explore even than Mars, this is the only other world we know that you could visit without a spacesuit. Rug up for the cold and fly a hot air balloon in Titanian skies, trek across vast dune fields, or row across a Titanian lake. Just don't fall in or get caught in the rain: it's liquid natural gas out here, not water, and it'll freeze you as hard as rock.