Enceladus Creating Saturn's E-Ring

Wispy fingers of bright, icy material reach tens of thousands of kilometers outward from Saturn's moon Enceladus into the E ring, while the moon's active south polar jets continue to fire away.

This astonishing, never-before-seen structure is made visible with the sun almost directly behind the Saturn system from Cassini's vantage point. The sun-Enceladus-spacecraft angle here is 175 degrees, a viewing geometry in which structures made of tiny particles brighten substantially.

These features are very likely the result of particles injected into Saturn orbit by the Enceladus geysers: Those injected in the direction of the moon's orbital motion end up on larger, slower orbits and trail Enceladus in its orbit, and those injected into the opposite direction end up smaller, faster orbits and lead Enceladus. (Orbital motion is counter-clockwise.) In addition, the configuration of wisps may hint at an interaction between Saturn's magnetosphere and the torrent of particles issuing from Enceladus.

In addition to the wisps, another unexpected detail is the dark gore in the center of the ring, following the moon in its orbit, likely brought about by the sweeping action of Enceladus as it orbits in the center of the E ring.

The view looks down onto Enceladus (505 kilometers, or 314 miles across) from about 15 degrees above the ringplane. Tethys (1,071 kilometers, or 665 miles across) is visible to the left of Enceladus.

The image was taken in visible light with the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Enceladus. Image scale is 128 kilometers (80 miles) per pixel.

Photo credit: NASA/JPL/Space Science Institute

Note: The above image is one of several used in a recent ESA press release, Herschel Confirms Enceladus as Primary Water Supply for Saturn's Atmosphere. This story is unique in that this is the first instance where a moon is directly affecting the atmosphere of the host planet.

Iapetus

The Cassini spacecraft takes one of its last good looks at Iapetus, a Saturnian moon known for its yin-yang-like, bright-and-dark color pattern.

This view looks toward the south pole of Iapetus (1,471 kilometers, or 914 miles across), and lit terrain seen here is in the southern latitudes of the trailing hemisphere. There is only one other planned viewing opportunity of Iapetus left in Cassini's Solstice Mission, in March 2015.

See PIA11690 to learn more about the color on Iapetus. See PIA08404 to learn more about the moon's equatorial ridge.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 7, 2011. The view was obtained at a distance of approximately 863,000 kilometers (536,000 miles) from Iapetus and at a Sun-Iapetus-spacecraft, or phase, angle of 98 degrees. Image scale is 5 kilometers (3 miles) per pixel.

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

Titan's North Polar Hood

The Cassini spacecraft examines Titan's north polar hood, the part of the atmosphere of Saturn's largest moon appearing dark at the top of this image.

See PIA09739 and PIA08137 to learn more about Titan's atmosphere. This view looks toward the anti-Saturn side of Titan. North on Titan (5,150 kilometers, or 3,200 miles across) is up. The southern pole of Titan is going into darkness, with the Sun advancing towards the north with each passing day. See PIA11603 and PIA11667 to learn more about the changing seasons in the Saturnian system. The upper layer of Titan's hazes is still illuminated by sunlight scattered off the planet.

The image was taken in visible violet light with the Cassini spacecraft wide-angle camera on April 19, 2011. The view was acquired at a distance of approximately 137,000 kilometers (85,000 miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 18 degrees. Image scale is 8 kilometers (5 miles) per pixel.

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

Updrafts of Large Ammonia Crystals in Saturn Storm

This false-color infrared image, obtained by NASA's Cassini spacecraft, shows clouds of large ammonia ice particles dredged up by a powerful storm in Saturn's northern hemisphere. Large updrafts dragged ammonia gas upward more than 30 miles (50 kilometers) from below. The ammonia then condensed into large crystals in the frigid upper atmosphere. This storm is the most violent ever observed at Saturn by an orbiting spacecraft.

Cassini's visual and infrared mapping spectrometer obtained these images on Feb. 24, 2011. Scientists colorized the image by assigning red to brightness detected from the 4.08-micron wavelength, green to brightness from the 0.90-micron wavelength, and blue to brightness from the 2.73-micron wavelength. Large particles (red) reflect sunlight well at 4.08 microns. Particles at high altitude (green) reflect sunlight well at 0.9 microns. Particles comprised of ammonia -- especially large ones -- do not reflect 2.73-micron sunlight well, but instead absorb light at this wavelength.

The storm here shows up as yellow, demonstrating that it has a large signal in both red and green colors. This indicates the cloud has large particles and extends upward to relatively high altitude. In addition, the lack of blue in the feature indicates that the storm cloud has a substantial component of ammonia crystals. The head of the storm is particularly rich in such particles, as created by powerful updrafts of ammonia gas from depth in the throes of Saturn's thunderstorm.

Photo credit: NASA/JPL/Univ. of Arizona

Rhea, Dione and the Rings

The Cassini spacecraft looks past the cratered south polar area of Saturn's moon Rhea to spy the moon Dione and the planet's rings in the distance.

Dione's "wispy" terrain can be seen on the trailing hemisphere of that moon. See PIA10560 to learn more.

This view looks toward the south polar area of the anti-Saturn side of Rhea (1,528 kilometers, or 949 miles across) and the Saturn-facing side of Dione (1,123 kilometers, or 698 miles across). North on the moons is up.

This view looks toward the northern, sunlit side of the rings from just above the ringplane. The rings, closer to Cassini than Dione is, obscure the view of the south of Dione.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on January 11, 2011. The view was acquired at a distance of approximately 61,000 kilometers (38,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 15 degrees. The view was acquired at a distance of approximately 924,000 kilometers (574,000 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 15 degrees. Image scale is 358 meters (1,175 feet) per pixel on Rhea and 6 kilometers (4 miles) per pixel on Dione.

Photo credit: NASA/JPL/Space Science Institute

Thin Line, Broad Shadows

Saturn's rings appear as only a thin line seen edge-on in the middle of this Cassini view, but the rings cast broad shadows on the southern hemisphere of the planet in the lower left of the image.

This view looks toward the southern, unilluminated side of the rings from just below the ringplane.

The image was taken with the Cassini spacecraft wide-angle camera on January 9, 2011 using a spectral filter sensitive to wavelengths of near-infrared light centered at 728 nanometers. The view was acquired at a distance of approximately 796,000 kilometers (494,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 147 degrees. Image scale is 44 kilometers (27 miles) per pixel.

Photo credit: NASA/JPL/Space Science Institute

Enceladus and Saturn's Rings

The Cassini spacecraft looks over cratered and tectonically deformed terrain on Saturn's moon Enceladus as the camera also catches a glimpse of the planet's rings in the background. The image was captured during the spacecraft's flyby of Enceladus on November 30, 2010.

Geologically young terrain in the middle latitudes of the moon gives way to older, cratered terrain in the northern latitudes. See PIA11685 to learn more. This view is centered on terrain at 41 degrees north latitude, 202 degrees west longitude. North on Enceladus (504 kilometers, or 313 miles, across) is up and rotated 28 degrees to the right.

This view looks toward the northern, sunlit side of the rings from less than a degree above the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera. The view was acquired at a distance of approximately 46,000 kilometers (29,000 miles) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 14 degrees. Image scale is 276 meters (906 feet) per pixel.

Photo credit: NASA/JPL/Space Science Institute

Hyperion

The Cassini spacecraft captures a view of the southern latitudes of Saturn's tumbling moon Hyperion.

To learn more about this spongy moon and how it tumbles in its orbit, see PIA06243, PIA07761 and PIA07740. Lit terrain seen here is mostly in the southern hemisphere of Hyperion (270 kilometers, or 168 miles across). The south pole of the moon is near the bottom of the illuminated terrain seen here.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on November 28, 2010. The view was obtained at a distance of approximately 80,000 kilometers (50,000 miles) from Hyperion and at a Sun-Hyperion-spacecraft, or phase, angle of 98 degrees. Image scale is 476 meters (1,562 feet) per pixel.

Photo credit: NASA/JPL/Space Science Institute

Dione and Enceladus

On the top right of this Cassini spacecraft image, Saturn's moon Dione may appear closer to the spacecraft because it is larger than the moon Enceladus in the lower left. However, Enceladus was actually closer to the spacecraft when this image was captured.

Dione (1,123 kilometers, or 698 miles, across) is actually more than twice the size of Enceladus (504 kilometers, or 313 miles, across). Dione's bright "wispy" terrain can be seen here. See PIA10560 and PIA06163 to learn more about this terrain. This view looks toward the area between the trailing hemisphere and Saturn-facing side of Dione.

The highly reflective surface of Enceladus also stands out here. This view looks toward the trailing hemisphere of Enceladus.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on December 1, 2010. The view was acquired at a distance of approximately 510,000 kilometers (317,000 miles) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 7 degrees. The view was acquired at a distance of approximately 830,000 kilometers (516,000 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 8 degrees. Image scale is 3 kilometers (2 miles) per pixel on Enceladus and 5 kilometers (3 miles) per pixel on Dione.

Photo credit: NASA/JPL/Space Science Institute

Enceladus

Saturn's moon Enceladus brightly reflects sunlight before a backdrop of the planet's rings and the rings' shadows cast onto the planet.

The Cassini spacecraft captured this snapshot during its flyby of the moon on November 30, 2010. This view looks toward the anti-Saturn side of Enceladus (504 kilometers, or 313 miles across). North on Enceladus is up and rotated 28 degrees to the right.

This view looks toward the northern, sunlit side of the rings from less than a degree above the ringplane.

The image was taken in visible light with the Cassini spacecraft wide-angle camera. The view was obtained at a distance of approximately 53,000 kilometers (33,000 miles) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 14 degrees. Image scale is 3 kilometers (2 miles) per pixel.

Photo credit: NASA/JPL/Space Science Institute