The swirling blue vortex at Saturn’s north poleNASA./JPL-Caltech/SSI/Jason MajorBy Leah CraneOn 26 April, the Cassini spacecraft swung between Saturn and its rings, closer than any spacecraft has ever been before. This was the start of its Grand Finale, which will end with its demise as it crashes into the planet. Here are some of the astonishing images...