Perhaps no spacecraft has provided such an endless stream of fascinating planetary images as Cassini has since it transmitted its first photos of Saturn and its environs in 2004. In this awesome picture (taken earlier this year), the planet’s F ring arcs like a silvery filament being molded by the moons Prometheus (visible) and Pandora. Prometheus even occasionally enters the ring itself as part of its sculpting process. Cassini will continue its extraordinarily successful mission until September 2017 when it will, alas, plunge into Saturn’s atmosphere to destroy itself.