Image Title: Jupiter's Amalthea Gossamer Ring Structure Target Name: J Rings Is a satellite of: Jupiter Mission: Galileo Spacecraft: Galileo Orbiter Instrument: Solid State Imaging Produced By: Cornell University Creation Date: 1998-09-15 Primary Data Set: Galileo EDRs Full-Res JPEG: R07_amalstruc_full.jpg (178 kbytes)

Original Caption Released with Image:

This mosaic of three images was taken with different sensitivities through the clear filter (610 nanometers) of the solid state imaging system aboard NASA's Galileo spacecraft on October 5, 1997. From the spacecraft's distance of approximately 6.6 million kilometers (km), the images have a resolution of about 134 km per pixel (picture element). The images were obtained when Galileo was in Jupiter's shadow, peering back toward the Sun. Since the spacecraft was located only about 0.15 degrees above the ring plane at the time, the images are highly foreshortened in the vertical direction. North is to the bottom.

The white vertical crescent at the left is caused by sunlight filtering through Jupiter's upper atmosphere. The white horizontal line in the left third of the figure is the main ring whose near and far arms overlap in this foreshortened view; the arms only separate very near the limb. The middle frame of the mosaic, taken at ten times higher sensitivity to detect fainter material, shows (on the left side of the panel) the overexposed main ring and the halo (seen as material above and below the main ring) which is interior to the main ring and has become visible in this longer exposure. The right panel, taken at the greatest sensitivity, shows a tenuous horizontal stripe, which can also be made out in the middle panel. In contrast to the main ring, which ends in a narrow elliptical tip, this "gossamer ring" ends abruptly without changing its vertical thickness; this ring is also unusual in that its top and bottom edges are about twice as bright as the central region. This ring disappears beyond the orbital distance of Amalthea, a small (mean radius of 85 km) Jovian moon, and has a half-thickness that is the same as Amalthea's maximum excursion off Jupiter's equatorial plane. The distances of the moons from Jupiter are given in units of Jovian radii; Jupiter's radius is 71,398 kilometers (44,267 miles).

The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/galileo. Background information and educational context for the images can be found at: http://www.jpl.nasa.gov/galileo/sepo.

Image Note:

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This page is not a Planetary PhotoJournal release, but is an illustration provided by the Galileo imaging (SSI) team as further background for other releases of imaging data.

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Galileo Solid State Imaging Team Leader: Dr. Michael J. S. Belton

The SSI Education and Public Outreach webpages were originally created and managed by Matthew Fishburn and Elizabeth Alvarez with significant assistance from Kelly Bender, Ross Beyer, Detrick Branston, Stephanie Lyons, Eileen Ryan, and Nalin Samarasinha.

Last updated: September 17, 1999, by Matthew Fishburn

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