Eyeful of Saturn

Saturn and its rings completely fill the field of view of Cassini’s narrow angle camera in this (top banner) natural color image taken on March 27, 2004. This is the last single ‘eyeful’ of Saturn and its rings achievable with the narrow angle camera on approach to the planet. From now until orbit insertion, Saturn and its rings will be larger than the field of view of the narrow angle camera.

Color variations between atmospheric bands and features in the southern hemisphere of Saturn, as well as subtle color differences across the planet’s middle B ring, are now more distinct than ever. Color variations generally imply different compositions. The nature and causes of any compositional differences in both the atmosphere and the rings are major questions to be investigated by Cassini scientists as the mission progresses.

The bright blue sliver of light in the northern hemisphere is sunlight passing through the Cassini Division in Saturn’s rings and being scattered by the cloud-free upper atmosphere.

saturn_ciclops
Scientists would like to know more about the origin of the ring ‘spokes’ imaged on Saturn by Voyager, but not so far by the current Cassini images. Image Credit: Cassini Imaging Team/Boulder/ ciclops.org

Two faint dark spots are visible in the southern hemisphere. These spots are close to the latitude where Cassini saw two storms merging in mid-March. The fate of the storms visible here is unclear. They are getting close and will eventually merge or squeeze past each other. Further analysis of such dynamic systems in Saturn’s atmosphere will help scientists understand their origins and complex interactions.

Moons visible in the full-resolution image are (clockwise from top right): Enceladus (499 kilometers or 310 miles across), Mimas (398 kilometers or 247 miles across), Tethys (1060 kilometers or 659 miles across) and Epimetheus (116 kilometers or 72 miles across). Epimetheus is dim and appears just above the left edge of the rings. Brightnesses have been exaggerated to aid visibility.

The image is a composite of three exposures, in red, green and blue, taken when the spacecraft was 47.7 million kilometers (29.7 million miles) from the planet. The image scale is 286 kilometers (178 miles) per pixel.

On May 18, Cassini officially enters the Saturn planetary system. On that day, the gravitational pull of Saturn begins to overtake the influence of the Sun and the probe crosses the outer limits of the most distant group of Saturnian moons, only weakly bound to Saturn and located tens of millions of kilometers from the planet.

The seven year voyage will end when Cassini’s main engine is fired, the spacecraft is slowed, and the probe enters Saturn orbit on July 1, 2004.


The Cassini-Huygens mission is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Office of Space Science, Washington, D.C.

Related Web Pages

Chronology of a Scientific Safari
Ring Recycling
Lord of the Rings
Long, Strange Trips
Titan’s Icy Bedrock
Saturn– JPL Cassini Main Page
Alien Landers: Extreme Explorers Hall of Fame