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