Titan - Extraterrestrial Land of Lakes

This colorized flyover movie from NASA's Cassini mission shows the two largest seas on Saturn's moon Titan and nearby lakes. Titan is the only world in our solar system other than Earth that has stable liquid on its surface. The liquid in Titan's lakes and seas is mostly methane and ethane.

The flight path starts at Titan's largest sea, Kraken Mare (about 680 miles or 1,100 kilometers long), and passes over the second largest sea, Ligeia Mare. Titan seas are named after sea monsters in world mythology. Then, there is an area with no topographical data and the flight path crosses an area with smaller lakes.

Lakes in this area are about 30 miles (50 kilometers) across or less.

Data for the movie was obtained by Cassini's radar instrument from 2004 to 2013. Heights of features were exaggerated 10 times. In this color scheme, liquids appear blue and black. Land areas appear yellow to white. A haze was added to simulate the Titan atmosphere.

Straight lines in the images are artifacts of how Cassini obtained the data.

The topographic mapping of Titan using stereo radar images was performed by the U.S. Geological Survey in Flagstaff, Arizona. The animation was created at JPL.

Video credit: NASA/JPL-Caltech/ASI/USGS

Note: For more information, see PIA17655: Titan's North and NASA's Cassini Spacecraft Reveals Clues About Saturn Moon

Saturn's North Polar Hexagon

This colorful view from NASA's Cassini mission is the highest-resolution view of the unique six-sided jet stream at Saturn's north pole known as "the hexagon." This movie, made from images obtained by Cassini's imaging cameras, is the first to show the hexagon in color filters, and the first movie to show a complete view from the north pole down to about 70 degrees north latitude.

Scientists can see the motion of a wide variety of cloud structures that reside within the hexagon in this movie. There is a massive hurricane tightly centered on the north pole, with an eye about 50 times larger than the average hurricane eye on Earth. (More information about that Saturn hurricane is at PIA14947.) Numerous small vortices are also present, which appear as reddish ovals. Some of these vortices spin clockwise while the hexagon and hurricane spin counterclockwise. Some of those smaller features are swept along with the jet stream of the hexagon, as if on a racetrack. The biggest of these vortices, seen near the lower right corner of the hexagon and appearing whitish, spans about 2,200 miles (3,500 kilometers), approximately twice the size of the largest hurricane on Earth.

The differences in this version of the movie, in which different wavelengths of light from ultraviolet to visible to infrared have been assigned colors, show a distinct contrast between the types of atmospheric particles inside and outside the hexagon. Inside the hexagon there are fewer large haze particles and a concentration of small haze particles, while outside the hexagon, the opposite is true. The jet stream that makes up the hexagon seems to act like a barrier, which results in something like the "ozone hole" in the Antarctic.

This movie shows a view from directly over the north pole, keeping up with the rotation of the planet so that all the motion seen on the screen is the motion of the hexagonal jet stream or the storms inside of it, without any added motion from the spinning of the planet itself. The original images were re-projected to show this polar view.

High-resolution views of the hexagon have only recently become possible because of the changing of the seasons at Saturn and changes in the Cassini spacecraft's orbit. The north pole was dark when Cassini first arrived in July 2004. The sun really only began to illuminate the entire interior of the hexagon in August 2009, with the start of northern spring. In late 2012, Cassini began making swings over Saturn's poles, giving it better views of the hexagon.

The eight frames of the movie were captured over 10 hours on December 10, 2012. Each of the eight frames consists of 16 map-projected images (four per color filter, and four filters per frame) so the movie combines data from 128 images total.

In this color scheme, scientists assigned red to the 0.750-micron part of the light spectrum (near infrared). This part of the spectrum penetrates the high-altitude haze layer to sense the top of tropospheric cloud deck. They assigned green to the 0.727-micron part of the light spectrum that senses the upper tropospheric haze (a near-infrared wavelength corresponding to a methane absorption band). They assigned blue to the sum of blue and ultraviolet broadband filters -- combined, this blue channel covers between 0.400 and 0.500 microns (covering very near ultraviolet to blue in visible light). This part of the spectrum is sensitive to small aerosols.

To human eyes, the hexagon and north pole would appear in tones of gold and blue. See PIA14945 for a still image of the area in natural color.

Video credit: NASA/JPL-Caltech/SSI/Hampton University

Note: For more information, see PIA17653: Hexagon in Silhouette, PIA17654: Looking Down on the Hexagon in Infrared, and NASA's Cassini Spacecraft Obtains Best Views of Saturn Hexagon.

Cassini Data: Titan May Have a Rigid Ice Shell

An analysis of gravity and topography data from the Saturnian moon Titan obtained by NASA's Cassini spacecraft suggests there could be something unexpected about the moon's outer ice shell. The findings, published on August 28 in the journal Nature, suggest that Titan's ice shell could be rigid, and that relatively small topographic features on the surface could be associated with large ice "roots" extending into the underlying ocean.

The study was led by planetary scientists Douglas Hemingway and Francis Nimmo at the University of California, Santa Cruz, who used data from Cassini. The researchers were surprised to find a counter-intuitive relationship between gravity and topography.

"Normally, if you fly over a mountain, you expect to see an increase in gravity due to the extra mass of the mountain," said Nimmo, a Cassini participating scientist. "On Titan, when you fly over a mountain, the gravity gets lower. That's a very odd observation."

One potential explanation is that each bump in the topography on the surface of Titan is offset by a deeper "root" that is big enough to overwhelm the gravitational effect of the bump on the surface. The root could act like an iceberg extending below the ice shell into the ocean underneath it. In this model, Cassini would detect less gravity wherever there is a big chunk of ice rather than water because ice is less dense than water.

"It's like a big beach ball under the ice sheet pushing up on it, and the only way to keep it submerged is if the ice sheet is strong," said Hemingway, the paper's lead author and a Cassini team associate. "If large roots under the ice shell are the explanation, this means that Titan's ice shell must have a very thick rigid layer."

If these findings are correct, a thick rigid ice shell makes it very difficult to have ice volcanoes, which some scientists have proposed to explain other features seen on the surface. They also suggest that convection or plate tectonics are not recycling Titan's ice shell, as they do with Earth's geologically active crust.

Video credit: ESA/NASA/JPL/University of Arizona

The Missing Waves of Titan

One of the most shocking discoveries of the past 10 years is how much the landscape of Saturn's moon Titan resembles Earth. Like our own blue planet, the surface of Titan is dotted with lakes and seas; it has river channels, islands, mud, rain clouds and maybe even rainbows. The giant moon is undeniably wet.

The "water" on Titan is not, however, H2O. With a surface temperature dipping 290 degrees F below zero, Titan is far too cold for liquid water. Instead, researchers believe the fluid that sculpts Titan is an unknown mixture of methane, ethane, and other hard-to-freeze hydrocarbons.

The idea that Titan is a wet world with its own alien waters is widely accepted by planetary scientists. Nothing else can account for the observations: NASA's Cassini spacecraft has flown by Titan more than 90 times since 2004, pinging the Moon with radar and mapping its lakes and seas. ESA's Huygens probe parachuted to the surface of Titan in 2005, descending through humid clouds and actually landing in moist soil.

Yet something has been bothering Alex Hayes, a planetary scientist on the Cassini radar team at Cornell University.

If Titan is really so wet, he wonders, "Where are all the waves?"

Here on Earth, bodies of water are rarely still. Breezes blowing across the surface cause waves to ripple and break; raindrops striking sea surfaces also provide some roughness. Yet on Titan, the lakes are eerily smooth, with no discernible wave action down to the millimeter scale, according to radar data from Cassini.

"We know there is wind on Titan," says Hayes. "The moon's magnificent sand dunes [prove] it."

Add to that the low gravity of Titan—only 1/7th that of Earth—which offers so little resistance to wave motion, and you have a real puzzle.

Researchers have toyed with several explanations. Perhaps the lakes are frozen. Hayes thinks that is unlikely, however, "because we see evidence of rainfall and surface temperatures well above the melting point of methane." Or maybe the lakes are covered with a tar-like substance that damps wave motion. "We can't yet rule that out," he adds.

The answer might be found in the results of a study Hayes and colleagues published in the July 2013 online edition of the journal Icarus. Taking into account the gravity of Titan, the low viscosity of liquid hydrocarbons, the density of Titan's atmosphere, and other factors, they calculated how fast wind on Titan would have to blow to stir up waves: A walking-pace breeze of only 1 to 2 mph should do the trick.

This suggests a third possibility: the winds just haven’t been blowing hard enough. Since Cassini reached Saturn in 2004, Titan’s northern hemisphere (where most of the lakes are located) has been locked in the grip of winter. Cold heavy air barely stirs, and seldom reaches the threshold for wave-making.

But now the seasons are changing. In August 2009 the sun crossed Titan’s equator heading north. Summer is coming, bringing light, heat and wind to Titan's lake country.

"According to [climate models], winds will pick up as we approach the solstice in 2017 and should be strong enough for waves," he says.

If waves appear, Cassini should be able to detect them. Radar reflections from wavy lake surfaces can tell researchers a great deal. Wave dimensions, for instance, may reveal the viscosity of the underlying fluid and, thus, its chemical composition. Also, wave speeds would track the speed of the overlying winds, providing an independent check of Titan climate models.

Hayes is excited about "bringing oceanography to another world. All we need now," he says, "are some rough seas."

Video credit: NASA

Video of Saturn's North Polar Hurricane

This movie, made from images obtained by NASA's Cassini spacecraft, shows the clouds of a hurricane-like storm, which circulate around the north pole of Saturn out to 88.5 degrees north latitude. The latitude of the bright ring of clouds is 89.0 degrees, which is about 587 miles (945 kilometers) from the pole. The eye of the storm is about 20 times larger than the average hurricane eye on Earth.

Winds are measured by following small clouds over a five-hour period. The winds at the inner ring are moving the fastest, at speeds of about 330 mph (50 meters per second) relative to the nominal rate for the planet established by NASA's Voyager spacecraft in 1980. These winds are four times the speed of the Earth's jet streams and more than four times the definition of a hurricane force wind on Earth. (Hurricane force winds blow at 74 mph, or 119 kilometers per hour.)

The clouds at the very center are spinning rapidly -- almost twice as fast as the planet itself, with a period just over six hours. The direction of rotation is counterclockwise, like a northern hemisphere hurricane on Earth, except there is no ocean underneath. A similar feature exists at Saturn's southern pole, and it spins in the same direction as that of a southern hemisphere hurricane on Earth. However, the hurricanes on Earth begin in the tropics and drift around. The polar hurricanes on Saturn are locked to their poles.

The bright clouds form a tightly wrapped spiral that traces a path toward the center as one follows it in a counterclockwise direction. This spiral could be a wave or actual particle motion toward the center from a disturbance further out. Or it could be the remnants of a compact cloud that got sheared apart by the higher angular velocity closer to the center. Choosing among these possibilities is the subject of ongoing research. Other ongoing research involves inferring cloud heights, both from the changing shadows as the sun moves relative to the features, and from the appearance of the clouds in other wavelengths, not shown in this set of black and white images.

This set of images is among the first sunlit views of Saturn's north pole captured by Cassini's imaging cameras. When the spacecraft arrived in the Saturnian system in 2004, it was northern winter and the north pole was in darkness.

The movie was constructed from seven images taken over five hours by Cassini's imaging science subsystem when the spacecraft was about 45 degrees above the horizon. Imaging team scientists re-projected the images to show a view from directly over the pole, keeping up with the rotation of the planet to make the clouds at 89.3 degrees latitude appear stationary. The winds at other latitudes produce the motion seen on the screen. They determined the rotation rate at each latitude, and interpolated in time to make a 200-step movie that flows smoothly as the clouds swirl around the center. To show the features at the center, the movie displays the motion relative to the clouds at 89.3 degrees latitude.

Video credit: NASA/JPL-Caltech/SSI


Note: For more information, see Mysterious Hurricane at Saturn's North Pole, NASA Probe Gets Close-Up Views of Large Hurricane on Saturn, Saturn's North-Pole Hurricane Close Up, and Gigantic Hurricane Spotted on Saturn.

Saturn Secrets Revealed

Thirty years ago the Voyager spacecraft offered the first closeup views of Saturn. Launched in 1997 Cassini-Huygens, a joint NASA/ESA/ASI mission, arrived around Saturn in July 2004 and the Huygens Probe landed on Titan, Saturn's largest moon, in January 2005. The ESA probe was the first to land on a world in the outer Solar System. Since 2005 Cassini-Huygens mission has obtained infinitely more detailed and beautiful images of the ringed planet and its many moons. Data from Cassini and Huygens are offering clues about how life began on Earth.

Text credit: ESA; video credit: ESA.

The Huygens Experience

Eight years ago today [14 January 2013], ESA’s Huygens bounced, slid and wobbled its way to rest on the surface of Saturn’s moon Titan, the first time a probe had touched down on an alien world in the outer Solar System.

The animation was created using real data recorded by Huygen’s instruments, allowing us to witness this historical moment as if we had been there.

The animation takes into account Titan’s atmospheric conditions, including the Sun and wind direction, the behavior of the parachute (with some artistic interpretation only on the movement of the ropes after touchdown), and the dynamics of the landing itself.

Even the stones immediately facing Huygens were rendered to match the photograph of the landing site returned from the probe, which is revealed at the end of the animation.

Split into four sequences, the animation first shows a wide-angle view of the descent and landing followed by two close-ups of the touchdown from different angles, and finally a simulated view from Huygens itself – the true Huygens experience.

New results published last year revealed that on first contact with Titan’s surface, Huygens dug a hole 12 cm deep, before bouncing out and sliding 30–40 cm across a flat surface.

The probe then wobbled back and forth five times until coming to a standstill about 10 seconds after touchdown – this is best seen in the final two sequences.

A ‘fluffy’ dust-like material – most likely organic aerosols that are known to drizzle out of the Titan atmosphere – was thrown up and suspended for around four seconds around the probe following the impact. The dust was easily lifted, suggesting it was most likely dry and that there had not been any ‘rain’ of liquid ethane or methane for some time prior to the landing.

Huygens was released from the international Cassini spacecraft on Christmas Day 2004, arriving at Titan three weeks later. Cassini has been in orbit around Saturn since July 2004, and will continue operations until 2017.

Video credit: ESA. Text credit: ESA.

Note: For more information, see When Huygens Met Titan.

Titan's South Polar Vortex

This true color image captured by NASA'S Cassini spacecraft before a distant flyby of Saturn's moon Titan on June 27, 2012, shows a south polar vortex, or a swirling mass of gas around the pole in the atmosphere.

The south pole of Titan (3,200 miles, or 5,150 kilometers, across) is near the center of the view.

Since Cassini arrived in the Saturn system in 2004, Titan has had a visible "hood" high above the north pole (see PIA08137). It was northern winter at Cassini's arrival, and much of the high northern latitudes were in darkness. But the hood, an area of denser, high altitude haze compared to the rest of the moon's atmosphere, was high enough to be still illuminated by sunlight. The seasons have been changing since Saturn's August 2009 equinox signaled the beginning of spring in the northern hemisphere and fall in the southern hemisphere for the planet and its many moons. Now the high southern latitudes are moving into darkness. The formation of the vortex at Titan's south pole may be related to the coming southern winter and the start of what will be a south polar hood.

See PIA14920 for a movie captured with a similar view and showing the polar vortex in motion.

These new, more detailed images are only possible because of Cassini's newly inclined orbits, which are the next phase of Cassini Solstice Mission. Previously, Cassini was orbiting in the equatorial plane of the planet, and the imaging team's images of the polar vortex between late March and mid-May were taken from over Titan's equator. At that time, images showed a brightening or yellowing of the detached haze layer on the limb, or edge of the visible disk of the moon, over the south polar region.

Scientists think these new images show open cell convection. In open cells, air sinks in the center of the cell and rises at the edge, forming clouds at cell edges. However, because the scientists can't see the layer underneath the layer visible in these new images, they don't know what mechanisms may be at work.

Cosmic ray hits on the camera detectors appear as bright dots in the black and white version of the image (Figure 1).

Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were obtained with the Cassini spacecraft narrow-angle camera late on June 26, 2012 at a distance of approximately 301,000 miles (484,000 kilometers) from Titan. Image scale is 2 miles (3 kilometers) per pixel.

Photo credit: NASA/JPL-Caltech/Space Science Institute; video credit: NASA/JPL-Caltech/Space Science Institute

Note: For more information, see The Titanian Seasons Turn, Turn, Turn; also, PIA14920: Titan's South Polar Vortex in Motion.

Mini-Jets in Saturn's F-Ring

New images from the Cassini spacecraft reveal rogue kilometer-sized objects punching through Saturn's F-ring as the source of 'mini-jets' seen emanating from the ring.

Saturn's narrow F-ring is already known to host a variety of dynamic features including channels, ripples and 'snowballs' that are created by the gravitational influence of nearby moon Prometheus. While some snowballs are likely broken up by collisions and tidal forces, the new images reveal five hundred separate cases where small surviving fragments punch through the F-ring, dragging icy ring particles with them.

The objects collide with the ring at low speeds of around two meters per second, resulting in 'mini-jets' that extend between 40 and 180 kilometers from the ring. In some cases the snowball impacts occur in groups, creating exotic patterns as they drag through the ring.

Video credit: NASA/JPL-Caltech/SSI/QMUL; text credit: ESA

Note: There are quite a few recent articles about this story; see:
* Cassini Movie Shows Blazing Trails in Saturn's F-ring
* Blazing Trails in Saturn’s F-ring Seen by Cassini
* PIA15500: Glittering Trail in Saturn's F Ring
* PIA15501: F Ring Patterns
* PIA15502: Small Trail at Saturn Orbit Insertion
* PIA15503: Classic Trails or Mini-Jets
* PIA15504: Exotic Trails or Mini-Jets
* PIA15505: Wavy, Wiggly Ring
* Cassini Sees Objects Blazing Trails in Saturn Ring

Saturn's Plasma and Radio Waves, as Seen by Cassini

This animation, derived from data obtained by NASA's Cassini spacecraft, shows how plasma swirling around Saturn is correlated to bursts of radio waves emanating from the planet. The data shown on the upper portion of the screen were obtained by the ion and neutral camera, part of the magnetospheric imaging instrument. When the plasma gets hot, it goes from red to white. The bottom part of the screen shows data from Cassini's radio and plasma wave subsystem. The data were obtained from 12:01 a.m. UTC to 11:55 a.m. UTC on October 7, 2008.

Video credit: NASA/JPL/JHUAPL/University of Iowa

Saturn's Hot Plasma Explosions

This animation based on data obtained by NASA's Cassini spacecraft shows how the "explosions" of hot plasma on the night side (orange and white) periodically inflate Saturn's magnetic field (white lines). Cassini scientists have been able to compute the "pressure" that the hot plasma exerts on the surrounding magnetic field by using remote images of the previously invisible hot plasma taken by the ion and neutral camera, part of the magnetospheric imaging instrument on board Cassini.

These enormous clouds of hot plasma recur in the part of the magnetosphere known as the magnetotail roughly every 10 to 11 hours. They rotate around Saturn at a distance of about eight to 15 times the radius of Saturn. Scientists have finally been able to demonstrate that the pressure contained in these clouds is sufficient to inflate the magnetic field in a manner that is consistent with the periodic magnetic field signals that have puzzled them for so long. As the high- and low-pressure systems of atmospheric weather on Earth produce winds, pressures in space produce huge electrical currents, which in turn distort the magnetic field.

The animation is based on data that were collected from December 17 to 18, 2004.

Video credit: NASA/JPL/JHUAPL/University of Iowa

Note: For more information, see Hot Plasma Explosions Inflate Saturn's Magnetic Field.

Unexpected Chevron Structure on the Edge of Saturn's B-Ring

The outer edge of Saturn's B ring exhibits an unexpected feature in this movie made from images captured by NASA's Cassini spacecraft. The images were obtained early in the planet's equinox "season" -- the period leading up to and away from August 11, 2009 when the Sun was over the planet's equator and lit the rings exactly edge on.

The B ring is shown at the top of the frame. The Cassini Division, a low-density region that separates the A and B rings, dominates the middle of the frame. The inner A ring is at the bottom.

It is apparent in the movie that the outer B ring edge location varies with time. For a more detailed view and explanation for this behavior, see PIA12794.

But, about halfway through, an unusual, 20,000-kilometer-long (12,000-mile-long), chevron-shaped structure can be seen moving along the B ring edge. Higher resolution images, taken during equinox, have shown that this region is the site of vertical structures, as tall as 3.5 kilometers (2.2 miles), whose existence was betrayed by long shadows (see PIA11668).

Cassini imaging scientists found that this chevron feature is one of two sites at the B ring's outer edge that does not follow any of the three newly discovered rotating patterns distorting the ring's edge or another pattern previously known to be caused by the moon Mimas. They have found instead that it orbits Saturn as would an independently orbiting body. As a result, scientists conclude that these are likely sites of massive bodies, or moonlets, embedded near the ring's edge but independently orbiting Saturn. In the particular region shown in this movie, the moonlets are likely big enough to cause ring material streaming past them to be excessively compressed and thrown vertically as a result. The moonlets themselves can't be seen.

This interpretation is supported by Cassini's previous discovery of a moonlet embedded in this region of the B ring (see PIA11665). The imaged moonlet, whose size is estimated at 300 meters (1,000 feet) across, was found only because it was betrayed by the shadow it cast during Saturn's August 2009 equinox period.

This view looks toward the southern, sunlit side of the rings from about 4 degrees below the ring plane.

The movie is a concatenation of 39 images taken about 2 minutes, 40 seconds apart, over the span of 1 hour, 40 minutes. The images, taken on February 25, 2009, were re-projected into the same viewing geometry.

...

The images were taken in visible light with the Cassini spacecraft narrow-angle camera. The view was obtained at a distance of approximately 822,000 kilometers (511,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 154 degrees. Image scale is 5 kilometers (3 miles) per pixel.

Video credit: NASA/JPL/Space Science Institute

Note: A continuous loop video of the chevron structure can be found here.

Galactic Behavior for the Outer B Ring

Keeping a close watch on the outer portion of Saturn's B ring, NASA's Cassini spacecraft records the complex inward and outward movement of the edge of the ring. This ring movement resembles the suspected behavior of spiral disk galaxies.

The position of the outer edge of the B ring, shown here crossing the middle of the frame, varies with time in this concatenation of 301 images taken an average of 1 minute, 50 seconds apart, over the span of about nine hours. The total variation of the edge, from the innermost to outermost locations, is 200 kilometers (120 miles). The eccentric Huygens Ringlet, another very narrow ringlet discovered by Cassini, and the innermost of the bands of ring material in the Cassini Division, a low-density region once thought to be empty, all appear in the top of the frame.

Cassini scientists have determined that the complicated radial variations in the B ring edge are caused by the presence of four scalloped patterns, all independently moving around the ring. One pattern, with two lobes, is present because of the gravitational perturbations from the moon Mimas, which alter the ring particle orbits because of a repetitive configuration of particle and satellite orbital positions known as a Lindblad resonance; this pattern always stays fixed with respect to Mimas.

The other patterns with one, two, and three lobes respectively, travel around the ring with differing speeds and are believed to be natural modes of oscillation of the ring in this vicinity, excited by a process known as "viscous overstability." In this process, the small, random motions of the ring particles feed energy into a wave that propagates outward across the ring from an inner boundary, reflects off the outer edge of the B ring (which becomes distorted as a result), and then travels inward until it reflects off the inner boundary. This continuous back-and-forth reflection is necessary for these wave patterns to grow and become visible as distortions in the outer edge of the B ring.

In supporting these so-called "self-excited" modes, the outer edge of the B ring is behaving the way astronomers believe spiral galaxies behave. However, such modes are not directly observable in galaxies. Cassini's observations of the outer B ring edge constitute the first time such large-scale modes in a broad disk of material have been observed in nature.

The movie repeats twice. The second time the movie runs, the location of the Mimas resonance (marked with a green line), the locations of the inner boundaries for the one-lobed (blue), two-lobed (yellow), and three-lobed (red) modes, and the location of the mean radius of the outer edge of the B ring (white) are all indicated.

The images were re-projected into the same viewing geometry and magnified by a factor of two to increase visibility of features. Image scale was about 2 kilometers (about 1 mile) per pixel in the original images. These images have not been cleaned of cosmic rays that struck the camera's sensor during exposure. These cosmic ray hits appear as small white streaks on the images.

The view looks toward the southern, sunlit side of the rings from about 44 degrees below the ring plane.

The images were taken in visible light with the Cassini spacecraft narrow-angle camera on January 28, 2008. The view was acquired at a distance of approximately 424,000 kilometers (264,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 52 degrees.

Video credit: NASA/JPL/Space Science Institute

Note: For a similar article and video, see PIA12795: Oscillations at B Ring Edge.