s our robotic emissary to Saturn, the Cassini spacecraft is privileged to behold such fantastic sights as this pairing of two moons beyond the rings. The bright, narrow F ring is the outermost ring structure seen here

NASA Cassini spacecraft looks toward Saturn tiny moon Aegaeon within the G-ring arc. The moonlet Aegaeon formerly known as S/2008 S 1 cant be seen in this image, but it orbits in the bright arc of Saturn faint G ring shown here.

This image obtained by NASA Cassini spacecraft of the outer edge of Saturn?s B ring, reveals the combined effects of a tugging moon and oscillations that can naturally occur in disks like Saturn rings and spiral galaxies.

A technician is pictured at the Marshall Space Flight Center welding the Y-ring to the S-IC stage bulkhead and the fuel tank for the Saturn V SA-502 launch vehicle (Apollo 6 mission) in building 4705. The size of the S-IC required a special rig known as the Y-ring to join the tank wall cylinders and domes together. The Y-ring was designed to eliminate lap joints where the tank domes, wall, and adjoining structure (such as the intertank segment) came together.

This image shows a region in Saturn's outer B ring. NASA's Cassini spacecraft viewed this area at a level of detail twice as high as it had ever been observed before. The view here is of the outer edge of the B ring, at left, which is perturbed by the most powerful gravitational resonance in the rings: the "2:1 resonance" with the icy moon Mimas. This means that, for every single orbit of Mimas, the ring particles at this specific distance from Saturn orbit the planet twice. This results in a regular tugging force that perturbs the particles in this location. A lot of structure is visible in the zone near the edge on the left. This is likely due to some combination of the gravity of embedded objects too small to see, or temporary clumping triggered by the action of the resonance itself. Scientists informally refer to this type of structure as "straw." This image was taken using a fairly long exposure, causing the embedded clumps to smear into streaks as they moved in their orbits. Later Cassini orbits will bring shorter exposures of the same region, which will give researchers a better idea of what these clumps look like. But in this case, the smearing does help provide a clearer idea of how the clumps are moving. This image is a lightly processed version, with minimal enhancement; this version preserves all original details present in the image. Another other version (Figure 1) has been processed to remove the small bright blemishes due to cosmic rays and charged particle radiation near the planet -- a more aesthetically pleasing image, but with a slight softening of the finest details. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Dec. 18, 2016. The view was obtained at a distance of approximately 32,000 miles (52,000 kilometers) from the rings and looks toward the unilluminated side of the rings. Image scale is about a quarter-mile (360 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA21057

NASA's Cassini spacecraft zoomed in on Saturn's A ring, revealing narrow, detailed structures that get even finer as the cameras' resolution increases. Even at this level of detail, it is still not fine enough to resolve the individual particles that make up the ring. High-resolution images like this help scientists map the fine structure of Saturn's rings. Features less than a half a mile (one kilometer) in size are resolvable here. But the particles in the A ring typically range in size from several meters across down to centimeters, making them still far too small to see individually here. This view looks toward the sunlit side of the rings from about 38 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 9, 2017. The view was obtained at a distance of approximately 70,000 miles (113,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 11 degrees. Image scale is 2,300 feet (690 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20526

This image from NASA's Cassini mission shows a region in Saturn's A ring. The level of detail is twice as high as this part of the rings has ever been seen before. The view contains many small, bright blemishes due to cosmic rays and charged particle radiation near the planet. The view shows a section of the A ring known to researchers for hosting belts of propellers -- bright, narrow, propeller-shaped disturbances in the ring produced by the gravity of unseen embedded moonlets. Several small propellers are visible in this view. These are on the order of 10 times smaller than the large, bright propellers whose orbits scientists have routinely tracked (and which are given nicknames for famous aviators). This image is a lightly processed version, with minimal enhancement, preserving all original details present in the image. he image was taken in visible light with the Cassini spacecraft wide-angle camera on Dec. 18, 2016. The view was obtained at a distance of approximately 33,000 miles (54,000 kilometers) from the rings and looks toward the unilluminated side of the rings. Image scale is about a quarter-mile (330 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA21059

NASA's Cassini spacecraft captured these remarkable views of a propeller feature in Saturn's A ring on Feb. 21, 2017. These are the sharpest images taken of a propeller so far, and show an unprecedented level of detail. The propeller is nicknamed "Santos-Dumont," after the pioneering Brazilian-French aviator. This observation was Cassini's first targeted flyby of a propeller. The views show the object from vantage points on opposite sides of the rings. The top image looks toward the rings' sunlit side, while the bottom image shows the unilluminated side, where sunlight filters through the backlit ring. The two images presented as figure 1 are reprojected at the same scale (0.13 mile or 207 meters per pixel) in order to facilitate comparison. The original images, which have slightly different scales, are also provided here, without reprojection, as figure 2; the sunlit-side image is at left, while the unlit-side image is at right. Cassini scientists have been tracking the orbit of this object for the past decade, tracing the effect that the ring has upon it. Now, as Cassini has moved in close to the ring as part of its ring-grazing orbits, it was able to obtain this extreme close-up view of the propeller, enabling researchers to examine its effects on the ring. These views, and others like them, will inform models and studies in new ways going forward. Like a frosted window, Saturn's rings look different depending on whether they are seen fully sunlit or backlit. On the lit side, the rings look darker where there is less material to reflect sunlight. On the unlit side, some regions look darker because there is less material, but other regions look dark because there is so much material that the ring becomes opaque. Observing the same propeller on both the lit and unlit sides allows scientists to gather richer information about how the moonlet affects the ring. For example, in the unlit-side view, the broad, dark band through the middle of the propeller seems to be a combination of both empty and opaque regions. The propeller's central moonlet would only be a couple of pixels across in these images, and may not actually be resolved here. The lit-side image shows that a bright, narrow band of material connects the moonlet directly to the larger ring, in agreement with dynamical models. That same thin band of material may also be obscuring the moonlet from view. Lengthwise along the propeller is a gap in the ring that the moonlet has pried open. The gap appears dark on both the lit and unlit sides. Flanking the gap near the moonlet are regions of enhanced density, which appear bright on the lit side and more mottled on the unlit side. One benefit of the high resolution of these images is that, for the first time, wavy edges are clearly visible in the gap. These waves are also expected from dynamical models, and they emphasize that the gap must be sharp-edged. Furthermore, the distance between the wave crests tells scientists the width of the gap (1.2 miles or 2 kilometers), which in turn reveals the mass of the central moonlet. From these measurements, Cassini imaging scientists deduce that the moonlet's mass is comparable to that of a snowball about 0.6 mile (1 kilometer) wide. For the original images, the lit-side image has a scale of 0.33 mile (530 meters) per pixel in the radial (or outward from Saturn) direction and 0.44 mile (710 meters) per pixel in the azimuthal (or around Saturn) direction. The different scales are the result of Cassini's vantage point being off to the side of the propeller, rather than directly above it. The unlit-side image has a scale of 0.25 (410 meters) per pixel in both directions. In order to preserve its original level of detail, the image has not been cleaned of bright blemishes due to cosmic rays and to charged particle radiation from Saturn. http://photojournal.jpl.nasa.gov/catalog/PIA21433

Icy Crown on Tethys

Swarm of Swirls

A Faint Ring Shines

Cassini Captures the Cassini Division

The F ring shows off a rich variety of phenomena in this image from NASA Cassini spacecraft.

Off the shoulder of giant Saturn, a bright pinpoint marks the location of the ring moon Atlas image center. Shadows cast by the C ring adorn the planet at upper right

The Prometheus Effect

The spoke-producing region of the B ring displays fine-scale asymmetry in the azimuthal direction -- the direction along which the ring particles orbit Saturn -- from upper left to lower right across the image

Prometheus Lurking in the Rings

Not-Quite-Empty Gap

Streaks of cloud are overlain with graceful ring shadows in this view of Saturn northern latitudes

An extreme enhancement of the original image, presented at right, reveals the grainy region with greater clarity

A dynamical interplay between Saturn largest moon, Titan, and its rings is captured in this view from NASA Cassini spacecraft.

Saturn Outer C Ring

Pulchritudinous Perturbations

Graceful Lanes of Ice

Saturn rings appear to form a majestic arc over the planet in this image from NASA Cassini spacecraft.

Sunlight filters through Saturn rings in sepia tones in this artful view from the Cassini spacecraft of the dark side of the rings

Spokes on Side of Saturn Rings

Two of Saturn moons orbit beyond four of the planet rings in this image from NASA Cassini spacecraft. From the top right of the picture are the C, B , A, and thin F rings, the small moon Pandora and, near the middle of the image, the moon Enceladus.

Ghostly spokes in Saturn B ring continue to put on a show for NASA Cassini spacecraft cameras in this recent image. The spokes, believed to be a seasonal phenomenon, are expected to disappear as Saturn nears its northern hemisphere summer.

Looking Through the Rings

The dark B ring of Saturn is highlighted here by numerous faint spokes. The two most prominent spokes are seen below and to the right of center

Mini Moon

Fingerprints of the Shepherds

Saturn's shadow stretched beyond the edge of its rings for many years after Cassini first arrived at Saturn, casting an ever-lengthening shadow that reached its maximum extent at the planet's 2009 equinox. This image captured the moment in 2015 when the shrinking shadow just barely reached across the entire main ring system. The shadow will continue to shrink until the planet's northern summer solstice, at which point it will once again start lengthening across the rings, reaching across them in 2019. Like Earth, Saturn is tilted on its axis. And, just as on Earth, as the sun climbs higher in the sky, shadows get shorter. The projection of the planet's shadow onto the rings shrinks and grows over the course of its 29-year-long orbit, as the angle of the sun changes with respect to Saturn's equator. This view looks toward the sunlit side of the rings from about 11 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Jan. 16, 2015. The view was obtained at a distance of approximately 1.6 million miles (2.5 million kilometers) from Saturn. Image scale is about 90 miles (150 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20498

In this image, NASA Cassini spacecraft has captured some of the structure of the tenuous D ring, appearing here as light/dark banding in the upper-right of the image.

Mysterious B Ring

Saturn rings are dark and elusive in this view from high above the ringplane, but their shadows on the planet give them away

Epimetheus is a lonely dot beyond Saturn rings. The little moon appears at lower left, outside the narrow F ring. Several very faint spokes lurk in the B ring, at right

NASA Cassini spacecraft images dark spokes on Saturn B ring. Spokes are radial markings on Saturn rings that continue to interest scientists, and they can be seen here stretching left to right across the image.

In this image from NASA Cassini spacecraft, the spiral structures in the D ring are on display, although it is so thin as to be barely noticeable compared to the rest of the ring system.

While the moon Epimetheus passes by, beyond the edge of Saturn main rings, the tiny moon Daphnis carries on its orbit within the Keeler gap of the A ring in this image from NASA Cassini spacecraft.

Propeller Belt

Cassini scientists continue their quest to understand the origin and evolution of the newly discovered features observed in Saturn A ring which have become known as propellers as shown in this image from NASA Cassini spacecraft.

Many Faces of the C Ring

Luminescent Rings

The A and F rings are alive with moving structures in this Cassini spacecraft view. Graceful drapes of ring material created by Prometheus are seen sliding by at left, while clumpy ringlets slip through the Encke Gap

Bright Arc of Ice

Turn of a Narrow Ring

Filtering the Sun

D Ring Sight Lines

Clumpy Construction

On the Border

The soft, bright-and-dark bands displayed by Saturn in this view from NASA Cassini spacecraft are the signature of methane in the planet atmosphere.

Looking upward from beneath the ringplane, the Cassini spacecraft spies Saturn's "wave maker" and "flying saucer" moons. Daphnis (8 kilometers, or 5 miles across at its widest point) and its gravitationally induced edge waves are seen at left within the Keeler Gap. The equatorial bulge on Atlas (30 kilometers, or 19 miles across at its widest point) is clearly visible here. See PIA06237 and PIA08405 for additional images and information about these two moons. This view looks toward the sunlit side of the rings from about 16 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 22, 2008. The view was acquired at a distance of approximately 898,000 kilometers (558,000 miles) from Saturn. Image scale is about 5 kilometers (3 miles) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA09907

The Cassini spacecraft peers through the gossamer strands of Saturn innermost rings, whose own shadows adorn the planet beyond

With the Sun directly behind Cassini, the spacecraft spies the opposition surge in Saturn inner A ring. The opposition effect becomes visible from this special viewing geometry

Bright spokes can be seen on Saturn B ring just in front of the shadow cast on the rings on the night side of the planet in this NASA Cassini spacecraft image.

NASA Cassini spacecraft spies two types of waves in Saturn A ring: a spiral density wave on the left of the image and a more pronounced spiral bending wave near the middle.

Two-image Mosaic of Saturn Rings

Arc in the Tenuous G Ring

The Cassini spacecraft spies multiple spokes in Saturn outer B ring. The precise origin and evolution of these transient features continue to provide ring scientists with intriguing puzzles to solve

Unidentified F Ring Objects

NASA Cassini spacecraft looks down at the unlit side of the rings as Pan heads into Saturn shadow. The moon is accompanied by faint ringlets in the Encke Gap.

Grace and Beauty

What That Speck?

This image from the Cassini spacecraft shows a ghostly white streak, called a spoke, in Saturn B ring. This is the first sighting of a spoke in nearly a year, and the first spoke seen by Cassini on the sunlit side of the rings

F Ring Channels

The F Ring Spiral Arm

High-resolution View of Saturn Rings

As Cassini watches the rings pass in front of bright red giant star Aldebaran, the star light fluctuates, providing information about the concentrations of ring particles within the various radial features in the rings

This Cassini spacecraft view shows a group of more than a dozen spokes in Saturn outer B ring. The B ring displays the azimuthal asymmetry, or variation with longitude around the planet, that is characteristic of the spoke-forming region

The Orbiting Fleet

Darkside Beauty

Saturn brightly lit rings slice across this NASA Cassini spacecraft picture taken before a backdrop of the planet clouds.

Among the Waves

Following the Clouds

New insights into the nature of Saturn’s rings are revealed in this panoramic mosaic of 15 images taken during the planet’s August 2009 equinox, taken by NASA Cassini Orbiter.

Saturn rings cut across an eerie scene that is ruled by Titan luminous crescent and globe-encircling haze, broken by the small moon Enceladus, whose icy jets are dimly visible at its south pole. North is up

Prometheus interacts gravitationally with the inner flanking ringlets of the F ring, creating dark channels as it passes

Double-Banded E Ring

The small moon Janus is almost hidden between the planet rings and the larger moon Rhea in this image captured by NASA Cassini spacecraft. The northern part of Janus can be seen peeking above the rings.

Two images of Saturn A and B ring showcase the opposition effect, a brightness surge that is visible on Saturn rings when the Sun is directly behind the spacecraft

Outer edge of Saturn B-ring

NASA Cassini spacecraft shows off this angled view of the rings and Saturn poles taken on Feb. 26, 2016.

Bright spokes grace Saturn B ring in this image taken by NASA Cassini spacecraft.

Delicate shadows are cast outward from Saturn thin F ring in the lower left of this image taken as the planet approached its August 2009 equinox. The moon Atlas 30 kilometers, or 19 miles across is seen just above the center of the image.

Petite Moon

Pandora Gets Kinky

This splendid view offers a detailed look at the faint rings within the Cassini Division as well as a rare glimpse of the Keeler gap moon, Daphnis. The small, ring embedded moon is a bright unresolved speck above center, near outer edge of A ring

Cassini stares toward the night side of Saturn, seen here on the right, as the active icy moon Enceladus glides past

Rounding the Corner

NASA Cassini spacecraft takes a look at Saturn diffuse E ring which is formed from icy material spewing out of the south pole of the moon Enceladus. The E ring is seen nearly edge-on from slightly above the northern side of Saturn ring plane.

Busy Moon

Cassini finds artistic harmony in the dark and icy realm of Saturn. The dim, unlit side of the rings is shown here. The narrow F ring appears bright when seen from angles near the plane of the rings

Pandora Shadow

Northern Sights

As ring particles emerge from the darkness of Saturn shadow, they pass through a region of twilight. The Sun light, refracted by the planet atmosphere, peeks around the limb, followed shortly by the Sun itself

This image, taken by NASA Cassini spacecraft, shows A beautiful mini-jet appearing in the dynamic F ring of Saturn. Saturn A ring including the Keeler gap and just a hint of the Encke gap at the upper-right also appears.

Dawn on Saturn is greeted across the vastness of interplanetary space by the morning star, Venus, in this image from NASA Cassini spacecraft. Venus appears just off the edge of the planet directly above the white streak of Saturn G ring.

Pan and Janus