From a distance Saturn seems to exude an aura of serenity and peace in this image from NASA's Cassini spacecraft. In spite of this appearance, Saturn is an active and dynamic world. Mimas is seen to the upper-right of Saturn.
NASA's Cassini captured these views of Saturn's icy moon Rhea on Feb. 9. The spacecraft returned to equatorial orbits around Saturn in March after nearly two years, allowing the mission to once again have close encounters with moons other than Titan.
From afar, Saturn's rings look like a solid, homogenous disk of material. But upon closer examination from NASA's Cassini spacecraft, we see that there are varied structures in the rings at almost every scale imaginable.
NASA's Cassini orbiter shows Saturn's main rings, seen here on their 'lit' face, appear much darker than normal. That's because they tend to scatter light back toward its source -- in this case, the Sun.
NASA's Cassini orbiter shows that Enceladus (visible in the lower-left corner of the image) is but a speck before enormous Saturn, but even a small moon can generate big waves of excitement throughout the scientific community.
NASA's Cassini orbiter shows Saturn is circled by its rings (nearly edge-on in this image), as well as by the moons Tethys (the large bright body near the lower right corner) and Mimas (seen as a slight crescent against Saturn's disk above the rings).
A new day dawns on Saturn as the part of the planet is seen emerging once more into the Sun's light by NASA's Cassini orbiter. With an estimated rotation period of 10 hours and 40 minutes, Saturn's days and nights are much shorter than those on Earth.
NASA's Cassini spacecraft spies Mimas, positioned against the shadow of Saturn's rings, bright on dark. As we near summer in Saturn's northern hemisphere, the rings cast ever larger shadows on the planet.
Saturn appears to NASA's Cassini's cameras as a thin, sunlit crescent in this unearthly view. Citizens of Earth, being so much closer to the Sun than Saturn, never get to enjoy a view of Saturn like this without the aid of our robot envoys.
Seen by NASA's Cassini spacecraft within the vast expanse of Saturn's rings, Prometheus appears as little more than a dot. But that little moon still manages to shape the F ring, confining it to its narrow domain.
The image on the left shows Cassini's view on approach to Phoebe, while the right shows the spacecraft's departing perspective. As it entered the Saturn system, NASA's Cassini spacecraft performed its first targeted flyby of one of the planet's moons.