Launched in 1997, NASA's Cassini spacecraft spent seven years traveling to Saturn before spending the past nine-and-a-half years orbiting the massive planet, making scientific observations and returning thousands of gorgeous otherworldly images. Saturn has more than 150 known moons and the most spectacular ring system of any of our neighboring planets. Its varied satellites include massive Titan, with a thick atmosphere and lakes of liquid ethane; icy Enceladus, spewing jets of water ice far into space; and two-toned Iapetus, with a mysterious equatorial ridge of mountains. Today, on the last day of the year, I thought it would be nice to look back on some of my favorite images from Cassini over the years, as we approach a decade of orbits next summer.