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Waves and Small Particles in
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PIA07960
Sol (our sun)
Radio Science Subsystem
| Title |
Waves and Small Particles in Ring A |
| Original Caption Released with Image |
Specially designed Cassini orbits place Earth and Cassini on opposite sides of Saturn's rings, a geometry known as occultation. Cassini conducted the first radio occultation observation of Saturn's rings on May 3, 2005. Three simultaneous radio signals at wavelengths of 0.94, 3.6, and 13 centimeters (Ka-, X-, and S-bands) were sent from Cassini through the rings to Earth. The observed change of each signal as Cassini moved behind the rings provided a profile of the distribution of ring material and an optical depth profile. This simulated image was constructed from the measured optical depth profiles of the Cassini Division and ring A. It depicts the observed structure at about 10 kilometers (6 miles) in resolution. The image shows the same ring A region depicted in a similar image (PIA07874 [ http://photojournal.jpl.nasa.gov/catalog/PIA07874 ]), using a different color scheme to enhance the view of a remarkable array of over 40 wavy features called "density waves" uncovered in the May 3 radio occultation throughout ring A. Color is used to represent information about ring particle sizes based on the measured effects of the three radio signals. Shades of red indicate regions where there is a lack of particles less than 5 centimeters (about 2 inches) in diameter. Green and blue shades indicate regions where there are particles of sizes smaller than 5 centimeters (2 inches) and 1 centimeter (less than one third of an inch), respectively. Note the gradual increase in shades of green towards the outer edge of ring A. It indicates gradual increase in the abundance of 5-centimeter (2-inch) and smaller particles. Note also the blue shades in the vicinity of the Keeler gap (the narrow dark band near the edge of ring A). They indicate increased abundance of even smaller particles of diameter less than a centimeter. Frequent collisions between large ring particles in this dynamically active region likely fragment the larger particles into more numerous smaller ones. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radio science team is based at JPL. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. For more information on the radio science team visit http://saturn.jpl.nasa.gov/spacecraft/instruments-cassini-rss.cfm [ http://saturn.jpl.nasa.gov/spacecraft/instruments-cassini-rss.cfm ]. |
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Multiple Eyes of Cassini
PIA07874
Sol (our sun)
Radio Science Subsystem
| Title |
Multiple Eyes of Cassini |
| Original Caption Released with Image |
Cassini instruments provide complementary information about the structure of Saturn's rings. Narrow and wide angle cameras provide images in the visible region of the electromagnetic, spectrum much like a digital camera does. The images have information about how the ring structure differs both with distance from the planet and with position around the equatorial circle. However, resolution is usually limited to few kilometers at best. Radio and stellar occultations of the rings also provide important information about ring structure, but only along a one-dimensional track through the rings. The radial resolution can be as fine as 50 meters (164 feet). An "image" is then constructed by assuming circular symmetry over the ring region of interest. Color is usually added to encode other information related to the observed structure. This image compares structure of Saturn's rings observed by these two approaches. The upper half is a natural color mosaic of images by the Cassini narrow-angle camera (see PIA06175 [ http://photojournal.jpl.nasa.gov/catalog/PIA06175 ]). The bottom simulated images is constructed from a radio occultation observation conducted on May 3, 2005. Color in the lower image is used to represent information about ring particle sizes. For another view created using this process (see PIA07872 [ http://photojournal.jpl.nasa.gov/catalog/PIA07872 ]). The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radio science team is based at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. For more information on the radio science team visit http://saturn.jpl.nasa.gov/spacecraft/instruments-cassini-rss.cfm [ http://saturn.jpl.nasa.gov/spacecraft/instruments-cassini-rss.cfm ]. The imaging team homepage is at http://ciclops.org [ http://ciclops.org ]. |
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Small Particles in Ring A
PIA07875
Sol (our sun)
Radio Science Subsystem
| Title |
Small Particles in Ring A |
| Original Caption Released with Image |
Specially designed Cassini orbits place Earth and Cassini on opposite sides of Saturn's rings, a geometry known as occultation. Cassini conducted the first radio occultation observation of Saturn's rings on May 3, 2005. Three simultaneous radio signals of 0.94, 3.6, and 13 centimeter wavelengths (Ka-, X-, and S-bands) were sent from Cassini through the rings to Earth. The observed change of each signal as Cassini moved behind the rings provided a profile of the distribution of ring material and an optical depth profile. This simulated image was constructed from the measured optical depth profiles of the Cassini Division and ring A. It depicts the observed structure at about 10 kilometers (6 miles) in resolution. Many radial features evident across ring A, but especially exterior to the Encke and Keeler gaps (the broad and narrow black bands on the right side of the image), are wavy features called 'density waves.' They are caused by gravitational interaction with moons outside ring A. Color is used to represent information about ring particle sizes based on the measured effects of the three radio signals. Shades of purple indicate regions where there is a lack of particles less than 5 centimeters (about 2 inches) in diameter. Green and blue shades indicate regions where there are particles of sizes smaller than 5 centimeters (2 inches) and 1 centimeter (less than one third of an inch), respectively. Note the gradual increase in shades of green towards the outer edge of ring A. It indicates gradual increase in the abundance of 5-centimeter (2-inch) and smaller particles. Frequent collisions between large ring particles in this dynamically active region likely fragment the larger particles into more numerous smaller ones. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radio science team is based at JPL. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. For more information on the radio science team visit http://saturn.jpl.nasa.gov/spacecraft/instruments-cassini-rss.cfm [ http://saturn.jpl.nasa.gov/spacecraft/instruments-cassini-rss.cfm ]. |
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Radio Occultation: Unravelin
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PIA07873
Sol (our sun)
Radio Science Subsystem
| Title |
Radio Occultation: Unraveling Saturn's Rings |
| Original Caption Released with Image |
Specially designed Cassini orbits place Earth and Cassini on opposite sides of Saturn's rings, a geometry known as occultation. Cassini conducted the first radio occultation observation of Saturn's rings on May 3, 2005. Three simultaneous radio signals of 0.94, 3.6, and 13 centimeter wavelength (Ka-, X-, and S-bands) were sent from Cassini through the rings to Earth. The observed change of each signal as Cassini moved behind the rings provided a profile of the distribution of ring material as a function of distance from Saturn, or an optical depth profile. This simulated image was constructed from the measured optical depth profiles. It depicts the observed ring structure at about 10 kilometers (6 miles) in resolution. Color is used to represent information about ring particle sizes in different regions based on the measured effects of the three radio signals. Purple color indicates regions where there is a lack of particles of size less than 5 centimeters (about 2 inches). Green and blue shades indicate regions where there are particles smaller than 5 centimeters (2 inches) and 1 centimeter (less than one third of one inch). The saturated broad white band near the middle of ring B is the densest region of ring B, over which two of the three radio signals were blocked at 10-kilometer (6-mile) resolution, preventing accurate color representation over this band. From other evidence in the radio observations, all ring regions appear to be populated by a broad range particle size distribution that extends to boulder sizes (several to many meters across). The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radio science team is based at JPL. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. For more information on the radio science team visit http://saturn.jpl.nasa.gov/spacecraft/instruments-cassini-rss.cfm [ http://saturn.jpl.nasa.gov/spacecraft/instruments-cassini-rss.cfm ]. |
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Small Particles in Saturn?s
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PIA07872
Sol (our sun)
Radio Science Subsystem
| Title |
Small Particles in Saturn?s Rings |
| Original Caption Released with Image |
Specially designed Cassini orbits place Earth and Cassini on opposite sides of Saturn's rings, a geometry known as occultation. Cassini conducted the first radio occultation observation of Saturn's rings on May 3, 2005. Three simultaneous radio signals of 0.94, 3.6, and 13 centimeter wavelengths (Ka-, X-, and S-bands) were sent from Cassini through the rings to Earth. The observed change of each signal as Cassini moved behind the rings provided a profile of the distribution of ring material as a function of distance from Saturn, or an optical depth profile. This simulated image was constructed from the measured optical depth profiles. It depicts the observed ring structure at about 10 kilometers (6 miles) in resolution. Color is used to represent information about ring particle sizes in different regions based on the measured effects of the three radio signals. Shades of purple, primarily over most of the inner ring (ring B) and the inner portion of the next ring (ring A), indicate regions where there is a lack of particles less than 5 centimeters (about 2 inches) in diameter. Green and blue shades indicate regions where there are particles of sizes smaller than 5 centimeters (2 inches) and 1 centimeter (less than one third of an inch), respectively, primarily in outer ring A and within most of ring C. From other evidence in the radio observations, all ring regions appear to be populated by a broad range of particle size distribution that extends to boulder sizes (several to many meters or yards across). The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radio science team is based at JPL. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. For more information on the radio science team visit http://saturn.jpl.nasa.gov/spacecraft/instruments-cassini-rss.cfm [ http://saturn.jpl.nasa.gov/spacecraft/instruments-cassini-rss.cfm ]. |
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Radio-Occultation Profiles (
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PIA02060
Sol (our sun)
Radio Science Subsystem
| Title |
Radio-Occultation Profiles (RS) |
| Original Caption Released with Image |
Vertical temperature and pressure structure observed in the northern and southern hemispheres. Upper panel for Ls = 270 (northern winter), lower panel for Ls=70 (southern winter), dashed line is freezing line for CO2 ice. |
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