Saturn is the sixth planet in the Sol (or Solar) System, which was John Crichton's home system. A gas giant, it is noted for its well-developed ring system. In 2003, Aeryn Sun took Crichton's father, Jack Crichton, on a trip to Saturn in her prowler. In doing so, the elder Crichton became the first human to venture to Saturn (though he conceded his son travelled a bit farther). During their brief visit, Sun piloted her prowler through the Cassini division in Saturn's rings. At the time of their visit, the Earth space probe, also named Cassini, was still en route to the planet.