Saturn Looms

Janus is spotted over Saturn's north pole in this image while Mimas' shadow glides across Saturn.

Janus is the faint dot that appears just above Saturn's north pole. Mimas' shadow can be seen in the southern hemisphere of Saturn, south of the rings' shadow. (Both objects are easier to find in higher resolution versions.)

This view looks toward the unilluminated side of the rings from about 25 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on August 24, 2012.

The view was obtained at a distance of approximately 1.6 million miles (2.6 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 80 degrees. Image scale is 94 miles (152 kilometers) per pixel. Janus has been brightened by a factor of 1.3 relative to Saturn to enhance its visibility.

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

Titan's Nile-like River

A miniature version of the Nile River, seen on Saturn’s moon Titan by the international Cassini mission. The river valley stretches more than 400 km from its ‘headwaters’ to a large sea, and likely contains hydrocarbons.

The image was acquired on 26 September 2012, on Cassini’s 87th close flyby of Titan. The river valley crosses Titan’s north polar region and runs into Kraken Mare, one of the three great seas in the high northern latitudes of the moon.

Photo credit: NASA/JPL–Caltech/ASI

Note: For more information, see Titan's Nile-Like River Valley.

Titan's South Polar Vortex

Titan's south polar vortex seems to float above the moon's south pole in this Cassini spacecraft view.

The vortex, which is a mass of gas swirling around the south pole high in the moon's atmosphere, can be seen in the lower right of this view. See PIA14919 and PIA14920 to learn more. The moon's northern hood is also visible in the top left of this view. See PIA08137 and PIA12775 to learn more about the hood.

This view looks toward the leading hemisphere of Titan (3,200 miles, or 5,150 kilometers across). North on Titan is up and rotated 25 degrees to the left.

The image was taken with the Cassini spacecraft narrow-angle camera on July 6, 2012 using a spectral filter sensitive to wavelengths of near-infrared light centered at 889 nanometers. The view was acquired at a distance of approximately 1.7 million miles (2.8 million kilometers) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 86 degrees. Scale in the original image was 11 miles (17 kilometers) per pixel. The image was contrast enhanced and magnified by a factor of 1.5 to enhance the visibility of surface features.

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

Pan in the Encke Gap

Saturn's tiny moon Pan orbits in the middle of the Encke Gap of the planet's A ring in this image from the Cassini spacecraft.

Pan (17 miles, or 28 kilometers across) is visible as a bright dot in the gap near the center of this view. See PIA12604 to see Pan casting a long shadow around the time of Saturn's August 2009 equinox.

The wide Roche Division separates the A ring from the thin F ring in the lower left quarter of the view. This view looks toward the southern, unilluminated side of the rings from about 20 degrees below the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 25, 2012. The view was obtained at a distance of approximately 1.2 million miles (2 million kilometers) from Pan. Image scale is 7 miles (12 kilometers) per pixel.

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

B-Ring Clumps and Strands

Zooming in on clumps in Saturn’s B-ring (lower left), the image also spans the ringlets of the Cassini Division towards the A-ring in the top right. The view looks toward the sunlit side of the rings from about 31 degrees below the ring plane. The image scale is approximately 2 km per pixel.

Photo credit: NASA/JPL/Space Science Institute

Atlas and the Rings

The Cassini spacecraft looks past Saturn's main rings to spy the tiny moon Atlas, which orbits between the main rings and the thin F ring.

The main rings are closer to the spacecraft than Atlas is, and the moon appears as only a small, white dot in the center of the image. This view looks toward the northern, sunlit side of the rings from just above the ringplane. See PIA08906 and PIA08405 for other views of Atlas (19 miles, 30 kilometers across).

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 16, 2012. The view was obtained at a distance of approximately 870,000 miles (1.4 million kilometers) from Atlas. Image scale is 5 miles (8 kilometers) per pixel.

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

Titan's South Polar Vortex

The Cassini spacecraft monitors Titan's developing south polar vortex, which is a mass of swirling gas around the pole in the atmosphere of the moon.

The vortex can be seen at the bottom of this view. See PIA14919 to learn more and PIA14920 to watch a short movie of the swirling mass. The moon's northern hood is also visible at the top of this view. See PIA08137 and PIA12775 to learn more about the hood.

This view looks toward the Saturn-facing side of Titan (3,200 miles, 5,150 kilometers across). North is up and rotated 14 degrees to the left.

The image was taken in visible blue light with the Cassini spacecraft narrow-angle camera on July 18, 2012. The view was acquired at a distance of approximately 1.9 million miles (3 million kilometers) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 85 degrees. Scale in the original image was 11 miles (18 kilometers) per pixel. The image was contrast enhanced and magnified by a factor of 1.5 to enhance the visibility of features.

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

Mimas Peeping Behind Dione

Saturn's moon Mimas peeps out from behind the larger moon Dione in this view from the Cassini spacecraft.

Mimas (246 miles, or 396 kilometers across) is near the bottom center of the image. Saturn's rings are also visible in the top right.

This view looks toward the anti-Saturn side of Dione (698 miles, or 1,123 kilometers across). North on Dione is up and rotated 20 degrees to the right. This view looks toward the northern, sunlit side of the rings from just above the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on December 12, 2011. The view was obtained at a distance of approximately 377,000 miles (606,000 kilometers) from Mimas. The view was obtained at a distance of approximately 56,000 miles (91,000 kilometers) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 42 degrees. Image scale is 1,773 feet (541 meters) per pixel on Dione.

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

Daphnis Making Waves

The Cassini spacecraft catches Saturn's moon Daphnis making waves and casting shadows from the narrow Keeler Gap of the planet's A ring in this view taken around the time of Saturn's August 2009 equinox.

Daphnis (8 kilometers, or 5 miles across) is almost invisible in this view, but the shadows cast on the wide A ring can be seen below the center of the image. The Encke Gap of the A ring, which is wider than the Keeler Gap, is on the right. Saturn's thin F ring is on the left of the view. See PIA11629 for a similar, closer view.

More than a dozen background stars are visible in this image.

Daphnis has an inclined orbit and its gravitational pull perturbs the orbits of the particles of the A ring forming the Keeler Gap's edge and sculpts the edge into waves having both horizontal (radial) and out-of-plane components. Material on the inner edge of the gap orbits faster than the moon so that the waves there lead the moon in its orbit. Material on the outer edge moves slower than the moon, so waves there trail the moon. See PIA11656 to learn more about this process.

The novel illumination geometry that accompanies equinox lowers the sun's angle to the ringplane, significantly darkens the rings, and causes out-of-plane structures to look anomalously bright and cast shadows across the rings. These scenes are possible only during the few months before and after Saturn's equinox which occurs only once in about 15 Earth years. Before and after equinox, Cassini's cameras have spotted not only the predictable shadows of some of Saturn's moons (see PIA11657), but also the shadows of newly revealed vertical structures in the rings themselves (see PIA11665).

This view looks toward the northern, sunlit side of the rings from about 13 degrees above the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on August 16, 2009. The view was acquired at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 108 degrees. Image scale is 12 kilometers (8 miles) per pixel.

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

Lightning Strike on Saturn

These false-color mosaics from NASA's Cassini spacecraft capture lightning striking within the huge storm that encircled Saturn's northern hemisphere for much of 2011.

The larger mosaic on the left of the panel shows the lightning flash, which appears as a blue dot. The smaller mosaic on the right is composed of images taken 30 minutes later, and the lightning is not flashing at that time.

See PIA14904 for a mosaic showing a wider view wrapping around the planet also in which some blue lightning is visible in the clouds.

The white arrow in the annotated version of this panel points to the location where the lightning occurred in the clouds. The optical energy of this and other flashes on Saturn is comparable to the strongest of the flashes on Earth. The flash is approximately 120 miles (200 kilometers) in diameter when it exits the tops of the clouds. From this, scientists deduce that the lightning bolts originate in the clouds deeper down in Saturn's atmosphere where water droplets freeze. This is analogous to where lightning is created on Earth.

This lightning flash appears only in the filter sensitive to blue visible light, and the images were enhanced to increase the visibility of the lightning.

Images taken using red, green and blue spectral filters are usually combined to create a natural color view. Because visible red-light images were not available, images taken using a spectral filter sensitive to wavelengths of near-infrared light centered at 752 nanometers were used in place of red. Also, the blue filter image was enhanced to increase the visibility of the lightning. The result is a type of false color image.

The images were obtained with the Cassini spacecraft narrow-angle camera on March 6, 2011, at a distance of approximately 2 million miles (3.3 million kilometers) from Saturn and at a sun-Saturn-spacecraft, or phase, angle of 83 degrees. These mosaics are simple cylindrical map projections, defined such that a square pixel subtends equal intervals of latitude and longitude. At higher latitudes, the pixel size in the north-south direction remains the same, but the pixel size (in terms of physical extent on the planet) in the east-west direction becomes smaller. The pixel size is set at the equator, where the distances along the sides are equal. This map has a pixel size of 12 miles (20 kilometers) at the equator.

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

Note: For more information, see Cassini Spots Daytime Lightning on Saturn.

Partial Eclipse of Enceladus, with Titan

Saturn's moon Enceladus is partially eclipsed by the planet in this Cassini spacecraft view which also features the moon Titan in the distance.

Cassini flew by Enceladus, shown in the center of the view, at a distance of about 16,000 miles (26,000 kilometers). The terminator between the day and night sides of Enceladus (313 miles, or 504 kilometers across) can be seen on the far left of the moon, while the shadow of the eclipsing planet runs across the bottom.

Titan (3,200 miles, or 5,150 kilometers across) is in the bottom right of this image and is about 684,000 miles (1.1 million kilometers) from the spacecraft. See PIA11508 to see Titan eclipsed by the planet.

This view looks toward the Saturn-facing sides of Enceladus and Titan. North is up.

The image was taken in visible light with the Cassini spacecraft wide-angle camera on October 1, 2011. The view was obtained at a Sun-Enceladus-spacecraft, or phase, angle of 29 degrees. Scale in the original image was 2 miles (3 kilometers) per pixel on Enceladus. The image was contrast enhanced and magnified by a factor of 1.5 to enhance the visibility of surface features.

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

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.

Formation of a High-Altitude Hood Over Titan's South Pole

False-color images from NASA's Cassini spacecraft show the development of a hood of high-altitude haze -- which appears orange in this image -- forming over the south pole of Saturn's moon Titan. These images were obtained on May 22 and June 7, 2012 by the visual and infrared mapping spectrometer in infrared wavelengths. Scientists assigned the colors red, green and blue to wavelengths mostly sensitive to the stratosphere, troposphere, and surface components, respectively. The newly discovered feature appears several hundred miles (kilometers) above the surface. When Cassini arrived at Saturn, it saw a hood of clouds and haze over Titan's north pole, which was experiencing winter. The south pole was basically clear, except for sporadic methane clouds. The seasons have been changing and the circulation in the upper atmosphere goes now from the illuminated north pole to the cooling south pole, causing downwellings over the south pole and formation of the hood.

Photo credit: NASA/JPL-Caltech/University of Arizona/LPGNantes

Pan Amid the Rings

NASA's Cassini spacecraft has recently resumed the kind of orbits that allow for spectacular views of Saturn's rings. This view, from Cassini's imaging camera, shows the outer A ring and the F ring. The wide gap in the image is the Encke Gap, where you see not only the embedded moon Pan but also several kinky, dusty ringlets. A wavy pattern on the inner edge of the Encke gap downstream from Pan and aspiral pattern moving inwards from that edge show Pan's gravitational influence. The narrow gap close to the outer edge is the Keeler gap.

Photo credit: NASA/JPL-Caltech/SSI

The Sikorsky Propeller

These three Cassini images show a propeller-shaped structure created by an unseen moon in Saturn's A ring. Propellers and other details of Saturn's rings are greeting scientists for the first time in two years, as Cassini's orbit took the spacecraft out of Saturn's equatorial plane in the spring of 2012, making face-on views of the rings possible again.

For years scientists have tracked this propeller, marked with red arrows here. These images are part of a growing catalog of "propeller" moons that, despite being too small to be seen, enhance their visibility by creating larger disturbances in the surrounding fabric of Saturn's rings.

This propeller, nicknamed "Sikorsky" after Russian-American aviator Igor Sikorsky, is about 30 miles (50 kilometers) long. See PIA12790, PIA12792 and PIA11672 to learn more about propellers.

In this most recent image, scientists knew they were observing a propeller they had seen before because Sikorsky was found close to the location predicted by a simple model of its motion. But its actual location did trail the predicted location by 6 degrees of longitude (8,000 miles, or 13,000 kilometers), underlining some of the changes known to occur in the orbits of propeller moons. These changes may occur because of interactions between the rings and the propeller moons. Scientists are eager to understand these interactions in Saturn's rings, as they may hold a key to similar systems such as solar systems forming from disks of matter.

In this most recent image, Sikorsky was found to trail its predicted position by 6 degrees of longitude (8,000 miles, or 13,000 kilometers), a discrepancy that underlines the changes that are known to occur in the orbits of propeller moons, possibly due to interactions between the rings and the embedded moons. Scientists are eager to understand these interactions in Saturn's rings, as they may hold a key to similar systems such as solar systems forming from disks of matter.

The Encke Gap of Saturn's A ring is on the right in the images. The A ring is the outermost of Saturn's main rings. This view looks toward the northern, sunlit side of the rings from about 12 degrees above the ringplane.

These images have not been cleaned of the effects of cosmic rays that struck the camera's sensor during exposure. These cosmic ray hits appear as small white specks or streaks on the images. These specks are not features in Saturn's rings. The image has been enhanced to aid visibility of compact objects like the propeller. The enhancement makes the edge of the Encke Gap appear dashed.

The images were taken in visible light with the Cassini spacecraft narrow-angle camera on June 5, 2012. The view was obtained at a distance of approximately 236,000 miles (380,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 24 degrees. Image scale is 1 mile (2 kilometers) per pixel.

Photo credit: NASA/JPL-Caltech/SSI/Cornell

Note: For more information, see Saturn's Rings are Back.

Bright Ejecta on Dione

Ejected material appears bright around some of Dione's craters in the image taken during the Cassini spacecraft's flyby of the moon on March 28, 2012.

This view is centered on terrain at 25 degrees north latitude, 128 degrees west longitude on Dione (698 miles, 1123 kilometers across).

See PIA10464 to see ejecta, or material thrown outward by the impact that formed a crater, covering a large area on the moon Rhea.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera. The view was acquired at a distance of approximately 28,000 miles (45,000 kilometers) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 55 degrees. Image scale is 876 feet (267 meters) per pixel.

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

The Shadow of Enceladus on Saturn

Saturn's rings cast wide shadows on the planet, and the shadow of a moon also graces the gas giant in this scene from the Cassini spacecraft.

The moon Enceladus is not shown in this view, but it does cast a small, elongated shadow on the planet near the bottom of this view. The moon Mimas (246 miles, or 396 kilometers across) is visible as a bright dot on the far right of the image in the ring plane.

This view looks toward the southern, unilluminated side of the rings from about 2 degrees below the ringplane.

The image was taken with the Cassini spacecraft wide-angle camera on Jan. 14, 2012 using a spectral filter sensitive to wavelengths of near-infrared light centered at 752 nanometers. The view was acquired at a distance of approximately 1.7 million miles (2.8 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 51 degrees. Image scale is 105 miles (170 kilometers) per pixel.

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

Titan's Internal Structure

A possible scenario for the internal structure of Titan, which includes a global subsurface ocean beneath an icy outer shell, as inferred by radio science data collected by the Cassini spacecraft.

Illustration credit: Angelo Tavani

http://www.jpl.nasa.gov/news/news.cfm?release=2012-190&rn=news.xml&rst=3419

A Jet Stream on Saturn

A particularly strong jet stream churns through Saturn's northern hemisphere in this false-color view from NASA's Cassini spacecraft.

Clouds associated with the jet stream can be seen in the upper right about a third of the way down from the top of this image. The jet stream clouds appear like a thin, bright orange line here. Moving west and closer to the center of the image, the feature drops south. Farther to the west of this discontinuity, or drop, a blurrier form of the jet stream clouds continues to move along the latitude circle.

See PIA14917 for a closer view and to learn how eddies, or rotating storms, give the jet stream its shape and speed.

The winds of Saturn's jet streams are zonal, meaning they move eastward or westward at particular latitudes. This jet stream is located at about 42 degrees north latitude, and has been visible on Saturn since the days of NASA's Voyager spacecraft (see PIA00027). In the Voyager days, this jet stream had an undulating appearance, leading scientists to dub it the "ribbon wave" (see PIA01378). The planet's atmosphere is always changing, and the jet stream now looks nothing like a ribbon.

Saturn's atmosphere and its rings are shown here in a false color composite made from three images taken in near infrared light through filters that are sensitive to varying degrees of methane absorption. Red and orange colors in this view indicate clouds that are deep in the atmosphere. Yellow and green colors, most noticeable near the top of the view, indicate intermediate clouds. White and blue indicate high clouds and haze.

The white clouds of the equatorial region appear oversaturated because the image was specially processed to bring out the wave.

The rings, in the upper left and lower left of the image, appear bright blue because they are outside of the atmosphere and not affected by methane absorption. This view looks toward the northern, unilluminated side of the rings from about 36 degrees above the ring plane.

The images were taken with the Cassini spacecraft wide-angle camera on January 13, 2008 using a combination of spectral filters sensitive to wavelengths of near-infrared light. The image filtered at 890 nanometers is projected as blue. The image filtered at 728 nanometers is projected as green, and the image filtered at 752 nanometers is projected as red.

The view was acquired at a distance of approximately 810,000 miles (1.3 million kilometers) from Saturn and at a sun-Saturn-spacecraft, or phase, angle of 55 degrees. Image scale is 46 miles (74 kilometers) per pixel.

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

Note: For more information, see PIA14917: Eddy-Powered Jet Stream; also, Cassini Shows Why Jet Streams Cross-Cut Saturn.

Titan

The Cassini spacecraft looks toward the dark side of Saturn's largest moon and captures the halo-like ring produced by sunlight scattering through the periphery of Titan's atmosphere.

A detached, high-altitude global haze layer encircles Titan. See PIA07774 to learn more. This view looks toward the Saturn-facing side of Titan (3,200 miles, or 5,150 kilometers across). North on Titan is up and rotated 29 degrees to the left.

The image was taken in visible green light with the Cassini spacecraft wide-angle camera on January 30, 2012. The view was obtained at a distance of approximately 123,000 miles (197,000 kilometers) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 162 degrees. Image scale is 7 miles (12 kilometers) per pixel.

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

Epimetheus and the Rings

The Cassini spacecraft watches Saturn's small moon Epimetheus orbiting beyond the planet's rings.

See PIA09813 and PIA06226 for closer views of this moon. Epimetheus (70 miles, or 113 kilometers across) orbits beyond the thin F ring near the bottom center of this view and is farther from the spacecraft than the rings are here. This view looks toward the southern, unilluminated side of the rings from about 1 degree below the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on December 30, 2011. The view was acquired at a distance of approximately 1.5 million miles (2.4 million kilometers) from Epimetheus. Image scale is 9 miles (14 kilometers) per pixel.

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

Tethys

The Cassini spacecraft takes a close look at a row of craters on Saturn's moon Tethys during the spacecraft's April 14, 2012, flyby of the moon.

Three large craters are visible along the terminator between day and night on Tethys (660 miles, or 1,062 kilometers across). The larger Odysseus crater also can be seen in profile on the right of the image. Odysseus Crater is 280 miles (450 kilometers) across. See PIA07693 for a closer view of Odysseus.

This view looks toward the area between the leading hemisphere and the anti-Saturn side of Tethys. North on Tethys is up and rotated 25 degrees to the right.

The image was taken in visible light with the Cassini spacecraft wide-angle camera on April 14, 2012. The view was acquired at a distance of approximately 12,000 miles (20,000 kilometers) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 66 degrees. Image scale is a half mile (1 kilometer) per pixel.

Photo credit:

NASA/JPL-Caltech/Space Science Institute

Light and Dark Titan

Light and dark halves of Titan are visible in this Cassini image which illustrates the seasonal changes in the northern and southern hemispheres. This picture was taken with a spectral filter that is sensitive to absorption of certain wavelengths of light by the methane present in the moon's atmosphere.

See PIA11603 to learn more about this seasonal hemispheric dichotomy. This view looks toward the anti-Saturn side of Titan (3,200 miles, or 5,150 kilometers across). North on Titan is up and rotated 29 degrees to the right. The moon's north polar hood is also visible in the top right of the view (see PIA08137 and PIA11594).

The image was taken with the Cassini spacecraft wide-angle camera on January 31, 2012 using a spectral filter sensitive to wavelengths of near-infrared light centered at 890 nanometers. The view was obtained at a distance of approximately 130,000 miles (210,000 kilometers) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 24 degrees. Image scale is 8 miles (12 kilometers) per pixel.

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

Methone

N00189072.jpg was taken on May 20, 2012 and received on Earth May 21, 2012. The camera was pointing toward METHONE, and the image was taken using the CL1 and CL2 filters. This image has not been validated or calibrated. A validated/calibrated image will be archived with the NASA Planetary Data System in 2013.

Photo credit: NASA/JPL/Space Science Institute

Note: For more information, see Cassini Spots Tiny Moon, Begins to Tilt Orbit.

Saturn and Tethys

Even in a peaceful looking scene such as this one of Saturn and its moon Tethys, the Cassini spacecraft reveals clues about how Saturn is ever-changing.

Saturn's northern hemisphere still shows the scars of the huge storm that raged through much of 2011 (see PIA14905). And, day by day, the shadows cast by the rings on the planet's southern hemisphere are growing wider as the seasons progress toward northern summer. See PIA11667 and PIA09793 to learn about the changing seasons and the shadows cast by the rings.

Tethys (660 miles, or 1,062 kilometers across) appears above the rings to the left of the center of the image.

The image was taken with the Cassini spacecraft wide-angle camera on January 10, 2012 using a spectral filter sensitive to wavelengths of near-infrared light centered at 752 nanometers. The view was obtained at a distance of approximately 1.4 million miles (2.3 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 39 degrees. Image scale on Saturn is 84 miles (136 kilometers) per pixel.

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

The Surface of Tethys

N00189019.jpg was taken on May 20, 2012 and received on Earth May 21, 2012. The camera was pointing toward TETHYS at approximately 37,196 miles (59,861 kilometers) away, and the image was taken using the CL1 and CL2 filters. This image has not been validated or calibrated. A validated/calibrated image will be archived with the NASA Planetary Data System in 2013.

Photo credit: NASA/JPL/Space Science Institute

Note: For more information, see Cassini Spots Tiny Moon, Begins to Tilt Orbit.

Map of Dione (December 2011)

This global map of Saturn's moon Dione was created using images taken during flybys by NASA's Cassini spacecraft.

An extensive system of bright ice cliffs created by tectonic fractures adorns the moon's trailing hemisphere, which is centered on 270 degrees west.

The map is a simple cylindrical (equidistant) projection and has a scale of 502 feet (153 meters) per pixel at the equator. The resolution of the map is 64 pixels per degree. The mean radius of Dione used for projection of this map is 350 miles (563 kilometers).

This map is an update to the version released in October 2010 (see PIA12814). This new map contains data from Cassini's December 12, 2011, flyby of Dione. Improved coverage is in the area around 45 degrees north latitude, 210 degrees west longitude.

Like other recent Dione global maps, this map has been shifted west by 0.6 degrees of longitude, compared to the 2006 version of the map (PIA08341), in order to conform to the International Astronomical Union longitude system convention for Dione.

The full unannotated tiff version can be downlinked here: PIA14914_full_2.tif. The full annotated tiff version PIA14914_full.tif. Photojournal note: these are large images and may be too large for some web browsers to handle. Users may right-click on the links to download the files to their desktop.

Map credit: NASA/JPL/Space Science Institute

Notes: The above map is only a small-scale image of the actual map available for download; the actual map (jpg file) can be found here. The north polar map of Dione can be found here.

Golden Night on Saturn

Saturn's B and C rings shine in diffuse, scattered light as the Cassini spacecraft looks on the planet's night side. The southern hemisphere is lit by sunlight reflecting off the rings, while the north shines much more feebly in the dim light that filters through the rings and is scattered on the northern hemisphere.

The fine, innermost rings are seen silhouetted against the southern hemisphere of the planet before partially disappearing into shadow.

The color of the rings appears more golden because of the increased scattering in the rings brought about by the high phase angle and the view being toward rings' the unlit side. Saturn also looks more golden because of the high phase angle here.

Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were obtained by the Cassini spacecraft wide-angle camera on September 28, 2006 at a distance of approximately 1.4 million kilometers (900,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 151 degrees. Image scale is 83 kilometers (51 miles) per pixel.

Photo credit: NASA/JPL/Space Science Institute

Daphnis, Pan and the Rings

Saturn's moons Daphnis and Pan demonstrate their effects on the planet's rings in this view from the Cassini spacecraft.

Daphnis (5 miles, or 8 kilometers across), on the left of the image, orbits in the Keeler Gap of the A ring. The moon's gravitational pull perturbs the orbits of the particles of the A ring forming the gap's edge and sculpts the edge into waves that move both in the ring's plane (radially) and out of the ring's plane. See PIA11655 and PIA12698 to learn more.

Pan (17 miles, or 28 kilometers across), in the top right of the image, orbits in the Encke Gap of the A ring. The effects of that moon's gravity can be seen as dark wakes on the parts of the rings below Pan in the image, propagating towards the middle of the image. See PIA07528 and PIA10529 to learn more.

This view looks toward the southern, unilluminated side of the rings from about 6 degrees below the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 3, 2010. The view was obtained at a distance of approximately 329,000 miles (529,000 kilometers) from Saturn. Image scale is 2 miles (3 kilometers) per pixel.

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

Janus

Shadows darken parts of some of Janus' large craters as Cassini takes a close look during its flyby of this Saturnian moon on March 27, 2012.

See PIA10447 and PIA12714 for higher resolution views of Janus (111 miles, or 179 kilometers across). See PIA08170 and PIA08348 to learn about how Janus periodically swaps orbits with Epimetheus.

This view is centered on terrain at 13 degrees south latitude, 26 degrees west longitude.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera. The view was acquired at a distance of approximately 28,000 miles (45,000 kilometers) from Janus and at a Sun-Janus-spacecraft, or phase, angle of 109 degrees. Image scale is 892 feet (272 meters) per pixel.

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

Bright Material on Dione

N00186374.jpg was taken on May 2, 2012 and received on Earth May 3, 2012. The camera was pointing toward DIONE at approximately 15,183 kilometers away, and the image was taken using the CL1 and CL2 filters. This image has not been validated or calibrated. A validated/calibrated image will be archived with the NASA Planetary Data System in 2013.

Photo credit: NASA/JPL/Space Science Institute

Dione and Rings

W00074064.jpg was taken on May 2, 2012 and received on Earth May 3, 2012. The camera was pointing toward DIONE at approximately 23,875 kilometers away, and the image was taken using the CL1 and CL2 filters. This image has not been validated or calibrated. A validated/calibrated image will be archived with the NASA Planetary Data System in 2013.

Photo credit: NASA/JPL/Space Science Institute

Wavy F-Ring

The constant change in Saturn's wavy, wiggly F ring is on display in this set of images obtained by NASA's Cassini spacecraft. The images show a view looking directly down onto the ring with the planet removed from the center. The radial distance from the center of the F ring has been exaggerated by a factor of 140 to make the wiggles and other radial structures more visible.

The regular patterns here primarily occur because of the gravitational pull of the moon Prometheus, which averages about 53 miles or 86 kilometers in diameter. Prometheus can create channels and snowballs as they part and push together icy F ring particles. These regular wiggles are about 65 miles (100 kilometers) from top to bottom.

Other processes are also at work. In the top left image, the object known as S/2004 S 6 – which may be a moonlet or just a dense clump – has produced an extended trail of material that can be seen at the top left of the image. A close-up of this event can be seen in PIA08863. In some of the images (bottom row, middle and right image), a bright spiral ring is visible. This was caused by an object, possibly S/2004 S 6, colliding with the main F ring and producing a trail of particles that subsequently sheared right around the planet. These events give the F ring its multi-stranded appearance.

Cassini's narrow-angle camera obtained the images in the top row on December 23, 2006; February 27, 2007 and March 17, 2007 (left to right). In the bottom row, the images were obtained on April 18, 2007; January 7, 2008 and February 24, 2008.

The F ring is the outermost of Saturn's main rings, with a radius of about 87,129 miles (140,220 kilometers).

Photo credit: NASA/JPL-Caltech/SSI/QMUL

Tethys, Enceladus and Saturn

A pair of Saturn's many moons joins the planet in this Cassini spacecraft scene.

Tethys (660 miles, or 1,062 kilometers across) appears as a small white dot above the rings on the far left of the image. Enceladus (313 miles, or 504 kilometers across) appears as a smaller bright speck beside the planet as seen from this vantage point. The rings cast wide shadows on the planet's southern latitudes.

This view looks toward the southern, unilluminated side of the rings from about 1 degree below the ringplane.

The image was taken in visible green light with the Cassini spacecraft wide-angle camera on January 19, 2012. The view was obtained at a distance of approximately 1.8 million miles (2.9 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 63 degrees. Image scale is 104 miles (167 kilometers) per pixel on Saturn.

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

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

The Face of Phoebe

Phoebe's true nature is revealed in startling clarity in this mosaic of two images taken during Cassini's flyby on June 11, 2004. The image shows evidence for the emerging view that Phoebe may be an ice-rich body coated with a thin layer of dark material. Small bright craters in the image are probably fairly young features. This phenomenon has been observed on other icy satellites, such as Ganymede at Jupiter. When impactors slammed into the surface of Phoebe, the collisions excavated fresh, bright material -- probably ice -- underlying the surface layer. Further evidence for this can be seen on some crater walls where the darker material appears to have slid downwards, exposing more light-colored material. Some areas of the image that are particularly bright - especially near lower right - are over-exposed.

An accurate determination of Phoebe's density -- a forthcoming result from the flyby -- will help Cassini mission scientists understand how much of the little moon is comprised of ices.

This spectacular view was obtained at a phase, or Sun-Phoebe-spacecraft, angle of 84 degrees, and from a distance of approximately 32,500 kilometers (20,200 miles). The image scale is approximately 190 meters (624 feet) per pixel. No enhancement was performed on this image.

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

Phoebe

This panel of images shows the nearly spherical shape of Saturn's moon Phoebe, as derived from imaging obtained from NASA's Cassini spacecraft. Each image represents a 90-degree turn.

Photo credit: NASA/JPL-Caltech/SSI/Cornell

Note: For more information, see Cassini Finds Saturn Moon has Planet-Like Qualities.

Rhea

Cassini looks over the heavily cratered surface of Rhea during the spacecraft's flyby of the moon on March 10, 2012.

See PIA08909 and PIA06553 to learn more about the impacts that have shaped the surface of Rhea (949 miles, or 1,528 kilometers across). This view is centered on terrain at 58 degrees north latitude, 84 degrees west longitude on Rhea.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera. The view was obtained at a distance of approximately 27,000 miles (43,000 kilometers) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 67 degrees. Image scale is 827 feet (252 meters) per pixel.

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

Ephemeral Lakes on Titan and Earth

Ontario Lacus is Titan's largest lake in its southern hemisphere. It is an ephemeral lake that resembles Etosha Pan in Namibia, Africa. On Titan the liquid is made of hydrocarbons, whereas on Earth it is made of water.

Photo credits: Cassini radar image: JPL/NASA. Envisat radar image: ESA. Composite image: LPGNantes.

Note: For more information, see Far-Off Cousin of Part-Time African Lake Found on Titan. See also Cassini Finds Titan Lake is Like a Namibia Mudflat.

Enceladus, Titan and the Rings

The brightly reflective moon Enceladus appears before Saturn's rings while the larger moon Titan looms in the distance.

Jets of water ice and vapor emanating from the south pole of Enceladus (hinting at a subsurface sea rich in organics), and liquid hydrocarbons ponding on the surface on the surface of Titan make these two of the most fascinating moons in the Saturnian system. See PIA07787 to learn more about these fascinating moons.

Enceladus (313 miles, or 504 kilometers across) is in the center of the image. Titan (3,200 miles, or 5,150 kilometers across) can faintly be seen in the background beyond the rings. This view looks toward the anti-Saturn side of Enceladus and the Saturn-facing side of Titan. The northern, sunlit side of the rings is seen from just above the ringplane.

The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on March 12, 2012. The view was acquired at a distance of approximately 600,000 miles (1 million kilometers) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 36 degrees. Image scale is 4 miles (6 kilometers) per pixel on Enceladus.

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