Cassini goodies: Telesto, Janus, Prometheus, Pandora, F ring

Janus is the 10th largest moon of Saturn, 196 x 192 x 150 kilometers in diameter and orbits along with Epimetheus between the F and G rings.

NASA / JPL / animation by Emily Lakdawalla

Epimetheus from Voyager 1

On November 12, 1980, Voyager 1 captured a series of images of Epimetheus through different color filters. During the sequence, the shadow of the F ring crossed the moon.

NASA / JPL / SSI / color composite by Gordan Ugarkovic

Telesto

Cassini captured this view of the leading hemisphere of Telesto on August 27, 2009. Telesto is a small moon, 34 x 28 x 36 kilometers in diameter, that occupies a Lagrange point behind Tethys in its orbit around Saturn. This is an approximately natural color view composed of raw images.

NASA / JPL / Space Science Institute

Saturn's moon Telesto

This raw image was captured by Cassini during its closest planned encounter with Telesto, on October 11, 2005.

NASA / JPL / SSI / animation by Mike Malaska

Prometheus, Pandora, and the F ring

Cassini captured the images that compose this animation on August 20, 2009. At present, Prometheus (the inner shepherd of the F ring) and the F ring collide with every orbit of Prometheus around Saturn. Prometheus dips into the F ring, causing a gore and pulling out a streamer of material. On the next orbit, Prometheus dips into the F ring ahead of its previous position. The result is a series of gores that slowly get sheared out as a result of the differential rates that the ring particles orbit Saturn (objects closer to Saturn complete one orbit in a shorter period of time than objects farther from Saturn). Pandora, the outer shepherd of the F ring, is also visible in this animation. The moons are lit from below by the Sun and from above by Saturnshine.