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North Atlantic Ocean
This is a radar image showin
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10/5/95
| Date |
10/5/95 |
| Description |
This is a radar image showing surface features on the open ocean in the northeast Atlantic Ocean. There is no land mass in this image. The purple line in the lower left of the image is the stern wake of a ship. The ship creating the wake is the bright white spot on the middle, left side of the image. The ship's wake is about 28 kilometers (17 miles) long in this image and investigators believe that is because the ship may be discharging oil. The oil makes the wake last longer and causes it to stand out in this radar image. A fairly sharp boundary or front extends from the lower left to the upper right corner of the image and separates two distinct water masses that have different temperatures. The different water temperature affects the wind patterns on the ocean. In this image, the light green area depicts rougher water with more wind, while the purple area is calmer water with less wind. The dark patches are smooth areas of low wind, probably related to clouds along the front, and the bright green patches are likely due to ice crystals in the clouds that scatter the radar waves. The overall "fuzzy" look of this image is caused by long ocean waves, also called swells. Ocean radar imagery allows the fine detail of ocean features and interactions to be seen, such as the wake, swell, ocean front and cloud effects, which can then be used to enhance the understanding of ocean dynamics on smaller and smaller scales. The image is centered at 42.8 degrees north latitude, 26.2 degrees west longitude and shows an area approximately 35 kilometers by 65 kilometers (22 by 40 miles). The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band horizontally transmitted, horizontally received, green is C-band horizontally transmitted, horizontally received, blue is L-band vertically transmitted, vertically received. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) imaging radar when it flew aboard the space shuttle Endeavour on April 11, 1994. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth. ##### |
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Titan Crater in Three Views
PIA07868
Saturn
Radar Imager, Visual and Inf
…
| Title |
Titan Crater in Three Views |
| Original Caption Released with Image |
. For more information about the visual and infrared mapping spectrometer visit http://wwwvims.lpl.arizona.edu/ [ http://wwwvims.lpl.arizona.edu/ ]., Figure 1: Titan Crater in Three Views This three-panel image shows one of Titan's most prominent impact craters in an infrared-wavelength image (left), radar image (center) and in the false-color image (right). The Cassini radar imaged this crater during Cassini's third flyby of Titan, on Feb. 15, 2005, (see PIA07368 [ http://photojournal.jpl.nasa.gov/catalog/PIA07368 ]). The crater, located at 16 degrees west, 11 degrees north, is about 80 kilometers (50 miles) in diameter and is surrounded beyond that by a blanket of material thrown out of the crater during impact. In radar, brighter surfaces mean rougher terrains, or else terrains tilted toward the radar. Two Titan flybys later, on April 16, the visual infrared mapping spectrometer on Cassini obtained images of the same crater. The panel on the left is an image at the 2.0 micron wavelength, showing that the crater has a dark floor and a small bright area in the center. The crater is surrounded by bright material, which has a very faint halo slightly darker than the surrounding dark material. Compare the radar image with the visual infrared mapping spectrometer image. Both the crater and the blanket of surrounding material (called ejecta) are bright at radar wavelengths, in the infrared, the crater itself is dark and this blanket of material is quite bright. In radar, the faint halo surrounding the blanket of material is quite similar in appearance to the rest of the ejecta blanket. The right hand panel is a false-color visual infrared mapping spectrometer image of the crater at lower resolution. It shows the faint halo to be slightly bluer than surrounding material. That the material is bluer than its surroundings, while also being darker, suggests that the faint halo is somewhat different in composition. This suggests that the composition of Titan's upper crust varies with depth, and various materials were excavated when the crater was formed. The same structure appearing so different to different instruments illustrates the importance of multiple instruments studying such phenomena. The Cassini spacecraft, being the most interdisciplinary spacecraft ever flown, strongly embodies such an approach. 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 and its two onboard cameras were designed, developed and assembled at JPL. The radar instrument team is based at JPL, working with team members from the United States and several European countries. The visual and infrared mapping spectrometer team is based at the University of Arizona, Tucson. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ] |
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Titan Crater in Three Views
PIA07868
Saturn
Radar Imager, Visual and Inf
…
| Title |
Titan Crater in Three Views |
| Original Caption Released with Image |
. For more information about the visual and infrared mapping spectrometer visit http://wwwvims.lpl.arizona.edu/ [ http://wwwvims.lpl.arizona.edu/ ]., Figure 1: Titan Crater in Three Views This three-panel image shows one of Titan's most prominent impact craters in an infrared-wavelength image (left), radar image (center) and in the false-color image (right). The Cassini radar imaged this crater during Cassini's third flyby of Titan, on Feb. 15, 2005, (see PIA07368 [ http://photojournal.jpl.nasa.gov/catalog/PIA07368 ]). The crater, located at 16 degrees west, 11 degrees north, is about 80 kilometers (50 miles) in diameter and is surrounded beyond that by a blanket of material thrown out of the crater during impact. In radar, brighter surfaces mean rougher terrains, or else terrains tilted toward the radar. Two Titan flybys later, on April 16, the visual infrared mapping spectrometer on Cassini obtained images of the same crater. The panel on the left is an image at the 2.0 micron wavelength, showing that the crater has a dark floor and a small bright area in the center. The crater is surrounded by bright material, which has a very faint halo slightly darker than the surrounding dark material. Compare the radar image with the visual infrared mapping spectrometer image. Both the crater and the blanket of surrounding material (called ejecta) are bright at radar wavelengths, in the infrared, the crater itself is dark and this blanket of material is quite bright. In radar, the faint halo surrounding the blanket of material is quite similar in appearance to the rest of the ejecta blanket. The right hand panel is a false-color visual infrared mapping spectrometer image of the crater at lower resolution. It shows the faint halo to be slightly bluer than surrounding material. That the material is bluer than its surroundings, while also being darker, suggests that the faint halo is somewhat different in composition. This suggests that the composition of Titan's upper crust varies with depth, and various materials were excavated when the crater was formed. The same structure appearing so different to different instruments illustrates the importance of multiple instruments studying such phenomena. The Cassini spacecraft, being the most interdisciplinary spacecraft ever flown, strongly embodies such an approach. 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 and its two onboard cameras were designed, developed and assembled at JPL. The radar instrument team is based at JPL, working with team members from the United States and several European countries. The visual and infrared mapping spectrometer team is based at the University of Arizona, Tucson. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ] |
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