This image made available by NASA in April 2017 shows a still from the short film "Cassini's Grand Finale," with the spacecraft diving between Saturn and the planet's innermost ring. Launched in 1997, Cassini reached Saturn in 2004 and has been exploring it from orbit ever since. Cassini’s fuel tank is almost empty, so NASA has opted for a risky, but science-rich grand finale. (Photo by NASA/JPL-Caltech via AP Photo)
