Two Ringlets in the Encke Gap

Although it appears empty from a distance, the Encke gap in Saturn's A ring has three ringlets threaded through it, two of which are visible here.

Each ringlet has dynamical structure such as the clumps seen in this image. The clumps move about and even appear and disappear, in part due to the gravitational effects of Pan.

This view looks toward the sunlit side of the rings from about 27 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 11, 2013.

The view was obtained at a distance of approximately 199,000 miles (321,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 121 degrees. Image scale is 1 mile (2 kilometers) per pixel.

Image credit: NASA/JPL-Caltech/Space Science Institute

Saturn From Above

Saturn reigns supreme, encircled by its retinue of rings.

Although all four giant planets have ring systems, Saturn's is by far the most massive and impressive. Scientists are trying to understand why by studying how the rings have formed and how they have evolved over time.

Also seen in this image is Saturn's famous north polar vortex and hexagon.

This view looks toward the sunlit side of the rings from about 37 degrees above the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on May 4, 2014 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers.

The view was acquired at a distance of approximately 2 million miles (3 million kilometers) from Saturn. Image scale is 110 miles (180 kilometers) per pixel.

Image credit: NASA/JPL-Caltech/Space Science Institute

Note: For more information, see Supreme Saturn.

Methane Clouds Over Titan's Ligeia Mare

This animated sequence of Cassini images shows methane clouds moving above the large methane sea on Saturn's moon Titan known as Ligeia Mare.

The spacecraft captured the views between July 20 and July 22, 2014, as it departed Titan following a flyby. Cassini tracked the system of clouds as it developed and dissipated over Ligeia Mare during this two-day period. Measurements of the cloud motions indicate wind speeds of around 7 to 10 miles per hour (3 to 4.5 meters per second).

The timing between exposures in the sequence varies. In particular, there is a 17.5-hour jump between the second and third frames. Most other frames are separated by one to two hours.

A separate view, PIA18421, shows the location of these clouds relative to features in Titan's north polar region.

Animation credit: NASA/JPL-Caltech/Space Science Institute

Note: For more information, see Cassini Tracks Clouds Developing Over a Titan Sea.

Rhea and Epimetheus

Saturn has a great many more moons than our planet – a whopping 62. A single moon, Titan, accounts for an overwhelming 96% of all the material orbit the planet, with a group of six other smaller moons dominating the rest. The other 55 small satellites whizzing around Saturn make up the tiny remainder along with the gas giant’s famous rings.

One of the subjects of this Cassini image, Rhea, belongs to that group of six. Set against a backdrop showing Saturn and its intricate system of icy rings, Rhea dominates the scene and dwarfs its tiny companion, one of the 55 small satellites known as Epimetheus.

Although they appear to be close to one another, this is a trick of perspective – this view was obtained when Cassini was some 1.2 million km from Rhea, and 1.6 million km from Epimetheus, meaning the moons themselves had a hefty separation of 400,000 km.

However, even if they were nearer to each other, Rhea would still loom large over Epimetheus: at 1528 km across and just under half the size of our own Moon, Rhea is well over 10 times the size of Epimetheus, which is a modest 113 km across.

As is traditional for the earliest discovered moons of Saturn, both are named after figures from Greek mythology: the Titan Rhea (“mother of the gods”) and Prometheus’ brother Epimetheus (“after thinker” or “hindsight”).

This image was taken by Cassini’s narrow-angle camera on 24 March 2010. A monochrome version was previously released by NASA as PIA12638: Big and Small Before Rings.

Image credit: Image data credit: NASA/JPL-Caltech/Space Science Institute; Processed image copyright: G. Ugarković

Pandora and the Rings

The F ring shepherd Pandora is captured here along with other well-known examples of how Saturn’s moons shape the rings. From the narrow F ring, to the gaps in the A ring, to the Cassini Division, Saturn's rings are a masterpiece of gravitational sculpting by the moons.

Pandora (50 miles, or 81 kilometers across), along with its fellow shepherd Prometheus (53 miles, or 86 kilometers across), helps confine the F ring and keep it from spreading.

This view looks toward the unilluminated side of the rings from about 31 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on March 8, 2014.

The view was obtained at a distance of approximately 533,000 miles (858,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 63 degrees. Image scale is 32 miles (51 kilometers) per pixel.

Image credit: NASA/JPL-Caltech/Space Science Institute

Note: For more information, see Shepherd and Flock.

Saturn's North Polar Vortex

Like a giant eye for the giant planet, Saturn's great vortex at its north pole appears to stare back at Cassini as Cassini stares at it.

Measurements have sized the "eye" at a staggering 1,240 miles (2,000 kilometers) across with cloud speeds as fast as 330 miles per hour (150 meters per second). For color views of the eye and the surrounding region, see PIA14946 and PIA14944.

The image was taken with the Cassini spacecraft narrow-angle camera on April 2, 2014 using a combination of spectral filters which preferentially admit wavelengths of near-infrared light centered at 748 nanometers.

The view was obtained at a distance of approximately 1.4 million miles (2.2 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 43 degrees. Image scale is 8 miles (13 kilometers) per pixel.

Image credit: NASA/JPL-Caltech/Space Science Institute