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Enceladus Keeps the Home Fir
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| Description |
Enceladus Keeps the Home Fires Burning |
| Full Description |
On Nov. 9, 2006, Cassini's composite infrared spectrometer captured its first view of the infrared heat radiation emanating from the "tiger stripe" fractures at the south pole of Saturn's moon Enceladus (right) since the discovery of the hot spot 16 months earlier (left). The original discovery was made just before a close flyby of Enceladus on July 14, 2005, and coincided with the discovery of plumes of water-rich gas and ice particles jetting out of the tiger stripes. However, the spacecraft's orbit did not provide any good views of the south pole for follow-up observations until November 2006. The new observations were made from a range of 110,000 kilometers (68,350 miles), slightly more distant than the 80,000-kilometer range (49,700 miles) of the original observations. Comparison of the two images shows that the south polar region continues to be active, and the distribution of temperatures there has changed little in 16 months. The distribution of heat radiation suggests that most or all of the south polar heat comes from the tiger stripes themselves, though the individual stripes are not resolved at the approximate 30-kilometer (19-mile) spatial resolution of these images. The images show the intensity of heat radiation in the 10- to 16-micron wavelength range, translated into temperature and displayed in false color. Peak south polar temperature on both dates reached about 85 Kelvin (minus 306 degrees Fahrenheit), averaged over the 30-kilometer (19-mile) spatial resolution of the data. However, the variation in brightness with wavelength, which is also measured by the composite infrared spectrometer, reveals that the warm region includes small areas, possibly zones a few 100 meters (320 feet) wide along the length of the tiger stripes, that are at higher temperatures, reaching at least 130 Kelvin (minus 225 degrees Fahrenheit) and perhaps much warmer still. While the south polar tiger stripes are almost certainly heated by energy from the moon's interior, daytime regions at low latitudes are warmed by sunlight to temperatures in the high 70s Kelvin (about minus 320 degrees Fahrenheit). The white numbers on the images show west longitudes on Enceladus, which is 500 kilometers (310 miles) in diameter. The dashed line shows the terminator, the boundary between day and night. The blotchy appearance of the cooler regions away from the south pole, and of the sky beyond the globe of Enceladus, is an artifact resulting from the fact that apart from the polar hot spot, the composite infrared spectrometer can barely detect the very faint heat radiation from this very cold moon. 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, composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. *Image Credit:* NASA/JPL/GSFC/Southwest Research Institute |
| Date |
December 22, 2006 |
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Boulder-strewn Surface -- Wi
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| Description |
Boulder-strewn Surface -- Wide-angle Camera View |
| Full Description |
This wide-angle view is one of the highest resolution images yet acquired by Cassini and shows what appears to be a geologically youthful, tectonically fractured terrain. A higher resolution, narrow-angle view of the center of the terrain shown here is available (see Boulder-strewn Surface -- Narrow-angle Camera View), as well as a comparison view showing the position of the narrow-angle image within this image (see Boulder-strewn Surface). The image was taken during Cassini's very close flyby of Enceladus on July 14, 2005, from a distance of approximately 208 kilometers (129 miles) above Enceladus. Resolution in the image is about 37 meters (121 feet) per pixel. The image's contrast has been enhanced to improve the visibility of surface features. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
July 26, 2005 |
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Boulder-strewn Surface -- Na
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| Description |
Boulder-strewn Surface -- Narrow-angle Camera View |
| Full Description |
The tortured southern polar terrain of Enceladus appears strewn with great boulders of ice in this fantastic view, one of the highest resolution images obtained so far by Cassini of any world. Some smearing of the image due to spacecraft motion is apparent in this scene, which was acquired as Enceladus raced past Cassini's field of view near the time of closest approach. At the time, the imaging cameras were pointed close to the moon's limb (edge), rather than directly below the spacecraft. This allowed for less motion blur than would have been apparent had the cameras pointed straight down. Thus, the terrain imaged here was actually at a distance of 319 kilometers (198 miles) from Cassini. At this fine scale, the surface is dominated by ice blocks between 10 and 100 meters (33 and 330 feet) across. The origin of these icy boulders is enigmatic. Scientists are interested in studying the sizes and numbers of the blocks in this bizarre scene, and in understanding whether terrain covered with boulders is common on Enceladus. A wide-angle camera view centered on this location on Enceladus is available (see Boulder-strewn Surface -- Wide-angle Camera View), as well as a comparison view showing the position of this image within the wide-angle image (see Boulder-strewn Surface). The image was taken during Cassini's very close flyby of Enceladus on July 14, 2005, from a distance of approximately 208 kilometers (129 miles) above Enceladus. Resolution in the image is about 4 meters (13 feet) per pixel. The image has been contrast enhanced to improve the visibility of surface. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
July 26, 2005 |
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Zooming In On Enceladus -- M
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| Description |
Zooming In On Enceladus -- Mosaic |
| Full Description |
As it swooped past the south pole of Saturn's moon Enceladus on July 14, 2005, Cassini acquired high resolution views of this puzzling ice world. From afar, Enceladus exhibits a bizarre mixture of softened craters and complex, fractured terrains. This large mosaic of 21 narrow-angle camera images have been arranged to provide a full-disk view of the anti-Saturn hemisphere on Enceladus. This mosaic is a false-color view that includes images taken at wavelengths from the ultraviolet to the infrared portion of the spectrum, and is similar to another, lower resolution false-color view obtained during the flyby (see Enceladus in False Color). In false-color, many long fractures on Enceladus exhibit a pronounced difference in color (represented here in blue) from the surrounding terrain. A leading explanation for the difference in color is that the walls of the fractures expose outcrops of coarse-grained ice that are free of the powdery surface materials that mantle flat-lying surfaces. The original images in the false-color mosaic range in resolution from 350 to 67 meters (1,148 to 220 feet) per pixel and were taken at distances ranging from 61,300 to 11,100 kilometers (38,090 to 6,897 miles) from Enceladus. The mosaic is also part of a movie sequence of images from this flyby (see Zooming in on Enceladus). 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
July 26, 2005 |
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Craters and Cracks
| Description |
Craters and Cracks |
| Full Description |
This dramatic scene from Cassini illustrates an array of processes on Saturn's moon Enceladus, a once geologically active world. Most of the larger craters appear to have softened from their original, presumably crisp appearance, and are cross-cut here by numerous faults. Cassini acquired this high-resolution view of Enceladus during its closest encounter yet with any moon of Saturn. Toward the bottom of the scene, terrain containing fractured and softened craters gives way to essentially non-cratered terrain consisting of tectonic faults. The softened craters, fractured plains and wrinkled terrain on Enceladus suggest geologic activity has taken place in several episodes during the satellite's history. This activity might continue into the present time, although imaging team scientists have seen no evidence for current activity on the moon. Illumination of the scene is from the left. The image was obtained in visible light with the Cassini spacecraft narrow-angle camera on July 14, 2005, at a distance of about 11,500 kilometers (7,150 miles) from Enceladus, and at a Sun-Enceladus-spacecraft, or phase, angle of 46 degrees. The image scale is 67 meters (220 feet) per pixel. The image's contrast has been enhanced to aid visibility of surface features. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
July 25, 2005 |
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Enceladus in False Color
| Description |
Enceladus in False Color |
| Full Description |
As Cassini approached the intriguing ice world of Enceladus for its extremely close flyby on July 14, 2005, the spacecraft obtained images in several wavelengths that were used to create this false-color composite view. The surface of Saturn's moon Enceladus shows a range of crater ages, including regions that have very few discernable craters at Cassini's resolution. This observation indicates that there have been multiple episodes of activity on Enceladus spread over some fraction of its history. The resurfacing mechanism appears to be dominated by tectonic fracturing. As of yet, there is no clear evidence for release of liquid to the surface in either icy volcanic flows or geysers. The south polar region (seen here at the lower right) has a distinctive tectonic structure that sets it apart from the rest of the satellite. Its outer boundary is marked by a series of pronounced tectonic "gashes" that form a hoop-like boundary, near 60 degrees south latitude. In this image, this fault zone forms the transition region from the presumably older, cratered terrain in the north to the younger, nearly crater-free region in the south. This false-color view is a composite of individual frames obtained using filters sensitive to ultraviolet (centered at 338 nanometers), green (centered at 568 nanometers) and infrared light (centered at 752 nanometers). The view has been enhanced to accentuate subtle color differences and fine-scale surface features. The Sun illuminates Enceladus from the lower left, leaving part of the moon in shadow. This view shows the anti-Saturn hemisphere, centered at 42 degrees south latitude, 167 west longitude. The images comprising this view were taken with the Cassini spacecraft narrow-angle camera at a distance of about 112,100 kilometers (69,700 miles) from Enceladus, and at a Sun-Enceladus-spacecraft, or phase, angle of 46 degrees. The image scale is about 670 meters (2,200 feet) per pixel. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
July 25, 2005 |
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Clues in the Bright and Dark
| Description |
Infrared view of Titan's bright Xanadu region |
| Full Description |
During a recent pass of Saturn's moon Titan, one of more than 40 during Cassini's planned four-year mission, the spacecraft acquired this infrared view of the bright Xanadu region and the moon's south pole. Titan is 5,150 kilometers (3,200 miles) across. Southeast of Xanadu (and above the center in this view) is a peculiar semi-circular feature informally referred to by imaging scientists as "the Smile." This surface feature is the brightest spot on Titan's surface, not only to the imaging science subsystem cameras, but also to the visual and infrared mapping spectrometer instrument, which sees the surface at even longer wavelengths (see Titan's Odd Spot Baffles Scientists ). The Smile is 560 kilometers (345 miles) wide. At the landing site of the successful Huygens probe mission, brighter regions correspond to icy upland areas, while the darker regions are lowlands that possess a higher proportion of the organic byproducts of Titan's atmospheric photochemistry. Those results seem to confirm the long-standing hypothesis that Xanadu is a relatively high region of less contaminated ice. However, the cause of the even brighter Smile is a mystery that is still under study. Farther south, a field of bright clouds arcs around the pole, moving at a few meters per second. Around the limb (edge), Cassini peers through Titan's smoggy, nitrogen-rich atmosphere. North in this image is toward the upper left. The image was taken with the Cassini spacecraft narrow-angle camera on June 4, 2005, at a distance of approximately 1.2 million kilometers (700,000 miles) from Titan using a spectral filter sensitive to wavelengths of infrared light centered at 938 nanometers. The image scale is 7 kilometers (4 miles) per pixel. 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 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 . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
July 14, 2005 |
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Warm Fractures on Enceladus
| Description |
Warm Fractures on Enceladus |
| Full Description |
This image shows the warmest places in the south polar region of Saturn's moon Enceladus. The unexpected temperatures were discovered by Cassini's composite infrared spectrometer during a close flyby on July 14, 2005. The image shows how these temperatures correspond to the prominent, bluish fractures dubbed "tiger stripes," first imaged by Cassini's imaging science subsystem cameras. Working together the two teams were able to pinpoint the exact location of the warmest regions on Enceladus. The composite infrared spectrometer instrument measured the infrared heat radiation from the surface at wavelengths between 9 and 16.5 microns within each of the 10 squares shown here. Each square is 6 kilometers (4 miles) across. The color of each square, and the number shown above it, describe the composite infrared spectrometer's measurement of the approximate average temperature of the surface within that square. The warmest temperature squares, at 91 and 89 degrees Kelvin (minus 296 and minus 299 degrees Fahrenheit), are located over one of the "tiger stripe" fractures. They contrast sharply with the surrounding temperatures, which are in the range 74 to 81 degrees Kelvin (minus 326 to minus 313 degrees Fahrenheit). The detailed composite infrared spectrometer data suggest that small areas near the fracture are at substantially higher temperatures, well over 100 degrees Kelvin (minus 279 degrees Fahrenheit). Such "warm" temperatures are unlikely to be due to heating of the surface by the feeble sunlight striking Enceladus' south pole. They are a strong indication that internal heat is leaking out of Enceladus and warming the surface along these fractures. Evaporation of this relatively warm ice probably generates the cloud of water vapor detected above Enceladus' south pole by several other Cassini instruments. Scientists are unsure how the internal heat reaches the surface. The process might involve liquid water, slushy brine, or soft but solid ice. The imaging science subsystem image is an enhanced color view with a pixel scale of 122 meters (400 feet) that was acquired at the same time as the composite infrared spectrometer data. It covers a region 125 kilometers (75 miles) across. The spacecraft's distance from Enceladus was 21,000 kilometers (13,000 miles). The broad bluer fractures that can be seen running from the upper left to the lower right of the image are 1 to 2 kilometers (0.6 to 1.2 miles) wide and more than 100 kilometers (60 miles) long. The fractures are thought to be bluer than the surrounding surface because coarser-grained ice (which has a blue color just as thick masses of ice, like glaciers and icebergs, do on Earth) has been exposed in the fractures. The color image was constructed using an ultraviolet filter (centered at 338 nanometers) in the blue channel, a clear filter in the green channel, and an infrared filter (centered at 930 nanometers) in the red channel. 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 composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/ . The imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/GSFC/Space Science Institute |
| Date |
July 29, 2005 |
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Enceladus Atmosphere -- Star
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| Description |
Enceladus Atmosphere -- Star Struck |
| Full Description |
During the July 14, 2005, flyby of Saturn's moon Enceladus, Cassini's ultraviolet imaging spectrograph made the first direct detection of an atmosphere, first suggested by Cassini magnetometer measurements. The ultraviolet imaging spectrograph observed the star Gamma Orionis as Enceladus crossed in front of the star. The light of the star dimmed as it was obscured by the atmosphere before being blocked entirely by Enceladus itself. The spectrum of the starlight changed as it passed through the atmosphere, indicating the presence of water vapor. The ultraviolet imaging spectrograph results suggest that the atmosphere of Enceladus is not constant and may be consistent with a greater amount of atmospheric gas near the south polar region. The presence of water vapor is more consistent with warm water ice than with magnetospheric sputtering. 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 ultraviolet imaging spectrograph was built at, and the team is based at the University of Colorado, Boulder. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The ultraviolet imaging spectrograph team home page is at http://lasp.colorado.edu/cassini . Credit: NASA/JPL/University of Colorado |
| Date |
July 29, 2005 |
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Enceladus Temperature Map
| Description |
Enceladus Temperature Map |
| Full Description |
This image shows the surprise that startled Cassini scientists on the composite infrared spectrometer team when they got their first look at the infrared (heat) radiation from the south pole of Saturn's moon Enceladus. There is a dramatic warm spot centered on the pole that is probably a sign of internal heat leaking out of the icy moon. The data were taken during the spacecraft's third flyby of this intriguing moon on July 14, 2005. Based on data from previous flybys, which did not show the south pole well, team members expected that the south pole would be very cold, as shown in the left panel. Enceladus is one of the coldest places in the Saturn system because its extremely bright surface reflects 80 percent of the sunlight that hits it, so only 20 percent is available to heat the surface. As on Earth, the poles should be even colder than the equator because the sun shines at such an oblique angle there. The right hand panel shows a global temperature image made from measurements of Enceladus' heat radiation at wavelengths between 9 and 16.5 microns. Cassini made the observation from a distance of 84,000 kilometers (52,000 miles) on the approach to Enceladus, and the image shows details as small as 25 kilometers (16 miles). Equatorial temperatures are much as expected, topping out at about 80 degrees Kelvin (-315 degrees Fahrenheit), but the south pole is occupied by a well-defined warm region reaching 85 Kelvin (-305 degrees Fahrenheit). That is 15 degrees Kelvin (27 degrees Fahrenheit) warmer than expected. The composite infrared spectrometer data further suggest that small areas of the pole are at even higher temperatures, well over 110 degrees Kelvin (-261 degrees Fahrenheit). Evaporation of this relatively warm ice probably generates the cloud of water vapor detected above Enceladus' south pole by several other Cassini instruments. The south polar temperatures are very difficult to explain if sunlight is the only energy source heating the surface, though exotic sunlight-trapping mechanisms have not yet been completely ruled out. It therefore seems likely that portions of the polar region are warmed by heat escaping from the interior of the moon. This would make Enceladus only the third solid body in the solar system, after Earth and Jupiter's volcanic moon Io, where hot spots powered by internal heat have been detected. 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 composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The composite infrared spectrometer team homepage is, http://cirs.gsfc.nasa.gov/ . Credit: NASA/JPL/GSFC |
| Date |
July 29, 2005 |
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Enceladus Atmosphere
| Description |
Artist concept of Enceladus' dynamic atmosphere |
| Full Description |
This artist concept shows the detection of a dynamic atmosphere on Saturn's icy moon Enceladus. The Cassini magnetometer instrument is designed to measure the magnitude and direction of the magnetic fields of Saturn and its moons. During Cassini's three close flybys of Enceladus -- Feb. 17, March 9 and July 14, 2005 -- the instrument detected a bending of the magnetic field around Enceladus due to electric currents generated by the interaction of atmospheric particles and the magnetosphere of Saturn. The graphic shows the magnetic field observed by Cassini, as well as the predicted neutral cloud being vented from the south pole. Cassini's magnetometer observed bending of the magnetic field consistent with its draping around a conducting object. That indicates that the Saturnian plasma is being diverted away from an extended atmosphere. 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 magnetometer team is based at Imperial College in London, working with team members from the United States and several European countries. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The magnetometer team homepage is http://www3.imperial.ac.uk/portal/page?_pageid=488,2068521&_dad=portallive&_schema=PORTALLIVE . Credit: NASA/JPL |
| Date |
July 29, 2005 |
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Looking Down on Epimetheus
| Description |
Looking Down on Epimetheus |
| Full Description |
From 34 degrees above Saturn's equatorial plane, Cassini gazed down at Saturn's moon Epimetheus. The region seen here includes territory farther north and east than that imaged in March 2005 (see Up-Close and Colorful ). The two largest craters visible here are the only officially named features on Epimetheus. The crater at the left (at about the 9 o'clock position) is named Pollux, the crater at lower left (containing a string of several smaller craters) is called Hilairea. Epimetheus is 116 kilometers (72 miles) across. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 14, 2005, at a distance of approximately 87,000 kilometers (54,000 miles) from Epimetheus and at a Sun-Epimetheus-spacecraft, or phase, angle of 95 degrees. The image scale is 520 meters (1,710 feet) per pixel. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
August 18, 2005 |
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Tiger Stripes are Cubs
| Description |
Tiger Stripes are Cubs |
| Full Description |
This visual and infrared mapping spectrometer image of Saturn's moon Enceladus (in the 2 micron-wavelength) shows the dark cracks at the south pole dubbed "tiger stripes" for their distinct stripe-like appearance. Superimposed on top of the map is a "crystallinity" map that shows the freshest, most crystal ice as blue. The crystalline ice is most prominent in the tiger stripes region. This image was taken during Cassini's close flyby of Enceladus on July 14, 2005. 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 visual and infrared mapping spectrometer team is based at the University of Arizona. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. The visual and infrared mapping spectrometer team homepage is at http://wwwvims.lpl.arizona.edu. Credit: NASA/JPL/University of Arizona |
| Date |
August 30, 2005 |
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Above Rhea's South Pole
| Description |
Above Rhea's South Pole |
| Full Description |
Cassini looks upward at the south polar region on Rhea during a recent distant encounter. Rhea's icy surface is so heavily saturated with impact craters that the moon's limb, or edge, has a rugged, bumpy appearance. Rhea is 1,528 kilometers (949 miles) across. The bright splotch seen here near the upper right is impact material (or ejecta) from a relatively fresh crater (see Great White Splat for another view of this bright feature). The image was taken with the Cassini spacecraft narrow-angle camera on July 14, 2005, at a distance of approximately 342,000 kilometers (212,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 36 degrees. The image was obtained using a filter sensitive to wavelengths of infrared light centered at 298 nanometers. The image scale is 2 kilometers (1 mile) per pixel. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
August 25, 2005 |
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Enceladus: The Plot Thickens
| Description |
Enceladus: The Plot Thickens |
| Full Description |
This graphic shows Cassini's path, or ground track, as it crossed over the surface of Enceladus near the time of closest approach during the flyby on July 14, 2005. The ground track is indicated by a yellow line, marked by increments of 10 seconds before and after closest approach. The spacecraft came within 175 kilometers (109 miles) from the surface of Enceladus at closest approach. The red contour encloses the region on Enceladus around the south pole that is the approximate boundary of the warm region, as measured by the composite infrared spectrometer instrument on Cassini. As previously announced, temperatures observed within this region reached as high as 110 Kelvin (-260 Fahrenheit). As Cassini passed over the southern polar terrain, its ion neutral mass spectrometer and cosmic dust analyzer instruments detected material coming from the surface of the moon. The ion neutral mass spectrometer measured a large peak in the abundance of water vapor at approximately 35 seconds before closest approach to Enceladus, as it flew over the south polar region at an altitude of 270 kilometers (168 miles). The high rate detector of the cosmic dust analyzer observed a peak in the number of fine, powder-sized icy particles coming from the surface approximately a minute before reaching closest approach at an altitude of 460 kilometers (286 miles). Analysis of this detection points to the south polar region as the source of the material. Results like these, pouring in from various Cassini instruments, indicate the warm south polar region and, in particular, the 'tiger stripe' fractures straddling the south pole, as the sources of heat, water vapor and small, icy particles. Enceladus is a surprisingly active moon. Why its south pole is the site of its activity is a mystery. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
August 30, 2005 |
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Water Vapor & Particles Over
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| Description |
Water Vapor & Particles Over Enceladus |
| Full Description |
This plot shows results from Cassini's ion neutral mass spectrometer and cosmic dust analyzer, obtained during the spacecraft's close approach to Enceladus on July 14, 2005. Within a minute of that closest approach, the two instruments detected material coming from the surface of the moon. The ion neutral mass spectrometer measured a large peak in the abundance of water vapor at approximately 35 seconds before closest approach to Enceladus, as it flew over the south polar region at an altitude of 270 kilometers (168 miles). The high rate detector of the cosmic dust analyzer observed a peak in the number of fine, powder-sized icy particles coming from the surface approximately a minute before reaching closest approach, at an altitude of 460 kilometers (286 miles). The character of these detections is very similar to the venting of vapor and fine, icy particles from the surfaces of comets when they are warmed as they near the Sun. On Enceladus however, it is believed that internal heat, possibly from tidal forces, is responsible for the activity. The close but different occurrences of the two detections are yielding important clues to the location of the vents and even the venting process. 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 ion and neutral mass spectrometer team is based at University of Michigan, Ann Arbor. The cosmic dust analyzer is operated by scientists at the Max Planck Institute in Heidelberg, Germany. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . Credit: NASA/JPL/University of Michigan/Max Planck Institute |
| Date |
August 30, 2005 |
|
Tiger Stripes Up Close
| Description |
Tiger Stripes Up Close |
| Full Description |
This close-up view of Saturn's moon Enceladus looks toward the moon's terminator (the transition from day to night) and shows a distinctive pattern of continuous, ridged, slightly curved and roughly parallel faults within the moon's southern polar latitudes. These surface features have been informally referred to by imaging scientists as "tiger stripes" due to their distinctly stripe-like appearance when viewed in false color (see Enceladus In False Color). Illumination of the scene is from the lower left. The image was obtained in visible light with the Cassini spacecraft narrow-angle camera on July 14, 2005, at a distance of about 20,720 kilometers (12,880 miles) from Enceladus, and at a Sun-Enceladus-spacecraft, or phase, angle of 46 degrees. The image scale is 122 meters (400 feet) per pixel. The image's contrast has been enhanced to aid visibility of surface features. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
July 25, 2005 |
|
Searching for Warmth
| Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. |
| Full Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by the composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is most strongly seen in the left-most composite infrared spectrometer field of view, which includes a fissure near the end of one of the tiger stripes. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See (PIA07794) for a related image. This image is centered near longitude 135 west, latitude 65 south, and each square from the composite infrared spectrometer field of view is 17.5 kilometers (10.9 miles) across. This Cassini narrow-angle camera image has been cropped and resized for presentation. 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 composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. The imaging team homepage is at http://ciclops.org *Credit:* NASA/JPL/GSFC/Space Science Institute |
| Date |
March 9, 2006 |
|
Enceladus the Storyteller
| Description |
A masterpiece of deep time and wrenching gravity, the tortured surface of Saturn's moon Enceladus and its fascinating ongoing geologic activity tell the story of the ancient and present struggles of one tiny world. |
| Full Description |
A masterpiece of deep time and wrenching gravity, the tortured surface of Saturn's moon Enceladus and its fascinating ongoing geologic activity tell the story of the ancient and present struggles of one tiny world. This is a story that is recounted by imaging scientists in a paper published in the journal Science on March 10, 2006. The enhanced color view of Enceladus seen here is largely of the southern hemisphere and includes the south polar terrain at the bottom of the image. Ancient craters remain somewhat pristine in some locales, but have clearly relaxed in others. Northward-trending fractures, likely caused by a change in the moon's rate of rotation and the consequent flattening of the moon's shape, rip across the southern hemisphere. The south polar terrain is marked by a striking set of 'blue' fractures and encircled by a conspicuous and continuous chain of folds and ridges, testament to the forces within Enceladus that have yet to be silenced. The mosaic was created from 21 false-color frames taken during the Cassini spacecraft's close approaches to Enceladus on March 9 and July 14, 2005. Images taken using filters sensitive to ultraviolet, visible and infrared light (spanning wavelengths from 338 to 930 nanometers) were combined to create the individual frames. The mosaic is an orthographic projection centered at 46.8 degrees south latitude, 188 degrees west longitude, and has an image scale of 67 meters (220 feet) per pixel. The original images ranged in resolution from 67 meters per pixel to 350 meters (1,150 feet) per pixel and were taken at distances ranging from 11,100 to 61,300 kilometers (6,900 to miles) from Enceladus. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
March 9, 2006 |
|
Searching for Warmth
| Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. |
| Full Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is near the center of the composite infrared spectrometer array, directly over a tiger stripe fissure. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite and infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See (PIA07793) for a related image. This image was taken nearly three times closer to the moon and is centered near longitude 120 west, latitude 82 south, and each composite infrared spectrometer field of view is 6.0 kilometers (3.7 miles) across. This Cassini narrow-angle camera image was cropped and resized for presentation. 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 composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. The imaging team homepage is at http://ciclops.org *Credit:* NASA/JPL/GSFC/Space Science Institute |
| Date |
March 9, 2006 |
|
Zooming In On Enceladus
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
As it swooped past the south pole of Saturn's moon Enceladus on July 14, 2005, Cassini acquired increasingly high-resolution views of this puzzling ice world. These views have been combined into this exciting movie sequence. The movie provides a stunning, up-close look at what is surely one of the youngest surfaces in the Saturn system. From afar, Enceladus exhibits a bizarre mixture of softened craters and complex, fractured terrains. The movie zooms in on the southern polar terrains and closes in on one of the tectonic stripes that characterize this region which is essentially free of sizeable impact scars. The bright oblong area seen during the zoom is an intermediate resolution image from near the time of closest approach that has been melded into the lower resolution mosaic, and artificially brightened. The movie ends on the highest resolution image acquired by Cassini which reveals a surface dominated by ice blocks between 10 and 100 meters (33 and 330 feet) across, lying in a region that is unusual in its lack of the very fine-grained frost that seems to cover the rest of Enceladus. The lack of frost and the absence of craters are indicators of a youthful surface. The initial image in the movie is a large mosaic of 21 narrow-angle camera images that have been arranged to provide a full-disk view of the anti-Saturn hemisphere on Enceladus. This mosaic is a false-color view that includes images taken at wavelengths from the ultraviolet to the infrared portion of the spectrum, and is similar to another, lower resolution false-color view obtained during the flyby (see Enceladus in False Color). In false-color, many long fractures on Enceladus exhibit a pronounced difference in color (represented here in blue) from the surrounding terrain. A leading explanation for the difference in color is that the walls of the fractures expose outcrops of coarse-grained ice that are free of the powdery surface materials that mantle flat-lying surfaces. The original images in the false-color mosaic range in resolution from 350 to 67 meters (1,148 to 220 feet) per pixel and were taken from distances ranging from 61,300 to 11,100 kilometers (38,090 to 6,897 miles) from Enceladus. The mosaic is also available separately (see Zooming in on Enceladus -- Mosaic). Image scale is about 37 meters (121 feet) per pixel in the wide-angle camera image and about 4 meters (13 feet) per pixel in the narrow-angle image (see Boulder-strewn Surface for these images). Both of these ultra-high resolution views were acquired from an altitude of approximately 208 kilometers (129 miles) above Enceladus as the spacecraft near the time of closest approach during the flyby. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
|
Zooming In On Enceladus
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
As it swooped past the south pole of Saturn's moon Enceladus on July 14, 2005, Cassini acquired increasingly high-resolution views of this puzzling ice world. These views have been combined into this exciting movie sequence. The movie provides a stunning, up-close look at what is surely one of the youngest surfaces in the Saturn system. From afar, Enceladus exhibits a bizarre mixture of softened craters and complex, fractured terrains. The movie zooms in on the southern polar terrains and closes in on one of the tectonic stripes that characterize this region which is essentially free of sizeable impact scars. The bright oblong area seen during the zoom is an intermediate resolution image from near the time of closest approach that has been melded into the lower resolution mosaic, and artificially brightened. The movie ends on the highest resolution image acquired by Cassini which reveals a surface dominated by ice blocks between 10 and 100 meters (33 and 330 feet) across, lying in a region that is unusual in its lack of the very fine-grained frost that seems to cover the rest of Enceladus. The lack of frost and the absence of craters are indicators of a youthful surface. The initial image in the movie is a large mosaic of 21 narrow-angle camera images that have been arranged to provide a full-disk view of the anti-Saturn hemisphere on Enceladus. This mosaic is a false-color view that includes images taken at wavelengths from the ultraviolet to the infrared portion of the spectrum, and is similar to another, lower resolution false-color view obtained during the flyby (see Enceladus in False Color). In false-color, many long fractures on Enceladus exhibit a pronounced difference in color (represented here in blue) from the surrounding terrain. A leading explanation for the difference in color is that the walls of the fractures expose outcrops of coarse-grained ice that are free of the powdery surface materials that mantle flat-lying surfaces. The original images in the false-color mosaic range in resolution from 350 to 67 meters (1,148 to 220 feet) per pixel and were taken from distances ranging from 61,300 to 11,100 kilometers (38,090 to 6,897 miles) from Enceladus. The mosaic is also available separately (see Zooming in on Enceladus -- Mosaic). Image scale is about 37 meters (121 feet) per pixel in the wide-angle camera image and about 4 meters (13 feet) per pixel in the narrow-angle image (see Boulder-strewn Surface for these images). Both of these ultra-high resolution views were acquired from an altitude of approximately 208 kilometers (129 miles) above Enceladus as the spacecraft near the time of closest approach during the flyby. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
|
Zooming in on Enceladus - Mo
…
| title |
Zooming in on Enceladus - Mosaic |
| description |
As it swooped past the south pole of Saturn's moon Enceladus on July 14, 2005 , Cassini acquired high resolution views of this puzzling ice world. From afar, Enceladus exhibits a bizarre mixture of softened craters and complex, fractured terrains. This large mosaic of 21 narrow-angle camera images have been arranged to provide a full-disk view of the anti-Saturn hemisphere on Enceladus. This mosaic is a false-color view that includes images taken at wavelengths from the ultraviolet to the infrared portion of the spectrum, and is similar to another, lower resolution false-color view obtained during the flyby (see NASA's Planetary Photojournal -- PIA06249 [ http://photojournal.jpl.nasa.gov/catalog/PIA06249 ]). In false-color, many long fractures on Enceladus exhibit a pronounced difference in color (represented here in blue) from the surrounding terrain. A leading explanation for the difference in color is that the walls of the fractures expose outcrops of coarse-grained ice that are free of the powdery surface materials that mantle flat-lying surfaces. The original images in the false-color mosaic range in resolution from 350 to 67 meters (1,148 to 220 feet) per pixel and were taken at distances ranging from 61,300 to 11,100 kilometers (38,090 to 6,897 miles) from Enceladus. The mosaic is also part of a movie sequence of images from this flyby (see NASA's Planetary Photojournal -- PIA06253 [ http://photojournal.jpl.nasa.gov/catalog/PIA06253 ]). 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov/ ] . The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org/ ] . *Credit:* NASA/JPL/Space Science Institute |
|
Tiger Stripes are Cubs
PIA03551
Saturn
Visual and Infrared Mapping
…
| Title |
Tiger Stripes are Cubs |
| Original Caption Released with Image |
This visual and infrared mapping spectrometer image of Saturn's moon Enceladus (in the 2 micron-wavelength) shows the dark cracks at the south pole dubbed "tiger stripes" for their distinct stripe-like appearance. Superimposed on top of the map is a "crystallinity" map that shows the freshest, most crystal ice as blue. The crystalline ice is most prominent in the tiger stripes region. This image was taken during Cassini's close flyby of Enceladus on July 14, 2005. 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 visual and infrared mapping spectrometer team is based at the University of Arizona. For more information about the Cassini-Huygens mission http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. The visual and infrared mapping spectrometer team homepage is at http://wwwvims.lpl.arizona.edu [ http://wwwvims.lpl.arizona.edu ]. |
|
Water Vapor & Particles Over
…
PIA03553
Saturn
Cosmic Dust Analyzer, Ion Ne
…
| Title |
Water Vapor & Particles Over Enceladus |
| Original Caption Released with Image |
Figure 1 for Water Vaport & Particles Over Enceladus This plot shows results from Cassini's ion neutral mass spectrometer and cosmic dust analyzer, obtained during the spacecraft's close approach to Enceladus on July 14, 2005. Within a minute of that closest approach, the two instruments detected material coming from the surface of the moon. The ion neutral mass spectrometer measured a large peak in the abundance of water vapor at approximately 35 seconds before closest approach to Enceladus, as it flew over the south polar region at an altitude of 270 kilometers (168 miles). The high rate detector of the cosmic dust analyzer observed a peak in the number of fine, powder-sized icy particles coming from the surface approximately a minute before reaching closest approach, at an altitude of 460 kilometers (286 miles). The character of these detections is very similar to the venting of vapor and fine, icy particles from the surfaces of comets when they are warmed as they near the Sun. On Enceladus however, it is believed that internal heat, possibly from tidal forces, is responsible for the activity. The close but different occurrences of the two detections are yielding important clues to the location of the vents and even the venting process. 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 ion and neutral mass spectrometer team is based at University of Michigan, Ann Arbor. The cosmic dust analyzer is operated by scientists at the Max Planck Institute in Heidelberg, Germany. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. |
|
Water Vapor & Particles Over
…
PIA03553
Saturn
Cosmic Dust Analyzer, Ion Ne
…
| Title |
Water Vapor & Particles Over Enceladus |
| Original Caption Released with Image |
Figure 1 for Water Vaport & Particles Over Enceladus This plot shows results from Cassini's ion neutral mass spectrometer and cosmic dust analyzer, obtained during the spacecraft's close approach to Enceladus on July 14, 2005. Within a minute of that closest approach, the two instruments detected material coming from the surface of the moon. The ion neutral mass spectrometer measured a large peak in the abundance of water vapor at approximately 35 seconds before closest approach to Enceladus, as it flew over the south polar region at an altitude of 270 kilometers (168 miles). The high rate detector of the cosmic dust analyzer observed a peak in the number of fine, powder-sized icy particles coming from the surface approximately a minute before reaching closest approach, at an altitude of 460 kilometers (286 miles). The character of these detections is very similar to the venting of vapor and fine, icy particles from the surfaces of comets when they are warmed as they near the Sun. On Enceladus however, it is believed that internal heat, possibly from tidal forces, is responsible for the activity. The close but different occurrences of the two detections are yielding important clues to the location of the vents and even the venting process. 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 ion and neutral mass spectrometer team is based at University of Michigan, Ann Arbor. The cosmic dust analyzer is operated by scientists at the Max Planck Institute in Heidelberg, Germany. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. |
|
Searching for Warmth
PIA07794
Saturn
Composite Infrared Spectrome
…
| Title |
Searching for Warmth |
| Original Caption Released with Image |
. The imaging team homepage is at http://ciclops.org [ http://ciclops.org ], The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is near the center of the composite infrared spectrometer array, directly over a tiger stripe fissure. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite and infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See PIA07793 [ http://photojournal.jpl.nasa.gov/catalog/PIA07793 ] for a related image. This image was taken nearly three times closer to the moon and is centered near longitude 120 west, latitude 82 south, and each composite infrared spectrometer field of view is 6.0 kilometers (3.7 miles) across. This Cassini narrow-angle camera image was cropped and resized for presentation. 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 composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/ [ http://cirs.gsfc.nasa.gov/ ] |
|
Searching for Warmth
PIA07793
Saturn
Composite Infrared Spectrome
…
| Title |
Searching for Warmth |
| Original Caption Released with Image |
http://cirs.gsfc.nasa.gov/ [ http://cirs.gsfc.nasa.gov/ ]. The imaging team homepage is at http://ciclops.org [ http://ciclops.org ], The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by the composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is most strongly seen in the left-most composite infrared spectrometer field of view, which includes a fissure near the end of one of the tiger stripes. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See PIA07794 [ http://photojournal.jpl.nasa.gov/catalog/PIA07794 ] for a related image. This image is centered near longitude 135 west, latitude 65 south, and each square from the composite infrared spectrometer field of view is 17.5 kilometers (10.9 miles) across. This Cassini narrow-angle camera image has been cropped and resized for presentation. 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 composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. The composite infrared spectrometer team homepage is |
|
Enceladus: The Plot Thickens
PIA07723
Saturn
Composite Infrared Spectrome
…
| Title |
Enceladus: The Plot Thickens |
| Original Caption Released with Image |
This graphic shows Cassini's path, or ground track, as it crossed over the surface of Enceladus near the time of closest approach during the flyby on July 14, 2005. The ground track is indicated by a yellow line, marked by increments of 10 seconds before and after closest approach. The spacecraft came within 175 kilometers (109 miles) from the surface of Enceladus at closest approach. The red contour encloses the region on Enceladus around the south pole that is the approximate boundary of the warm region, as measured by the composite infrared spectrometer instrument on Cassini. As previously announced, temperatures observed within this region reached as high as 110 Kelvin (-260 Fahrenheit). As Cassini passed over the southern polar terrain, its ion neutral mass spectrometer and cosmic dust analyzer instruments detected material coming from the surface of the moon. The ion neutral mass spectrometer measured a large peak in the abundance of water vapor at approximately 35 seconds before closest approach to Enceladus, as it flew over the south polar region at an altitude of 270 kilometers (168 miles). The high rate detector of the cosmic dust analyzer observed a peak in the number of fine, powder-sized icy particles coming from the surface approximately a minute before reaching closest approach at an altitude of 460 kilometers (286 miles). Analysis of this detection points to the south polar region as the source of the material. Results like these, pouring in from various Cassini instruments, indicate the warm south polar region and, in particular, the 'tiger stripe' fractures straddling the south pole, as the sources of heat, water vapor and small, icy particles. Enceladus is a surprisingly active moon. Why its south pole is the site of its activity is a mystery. 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. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. For additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
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Closer to Enceladus
PIA06246
Saturn
Imaging Science Subsystem -
…
| Title |
Closer to Enceladus |
| Original Caption Released with Image |
This map of the surface of Enceladus illustrates the regions that will be imaged by NASA's Cassini spacecraft during its planned very close flyby on July 14, 2005. At closest approach, the spacecraft is expected to pass approximately 175 kilometers (108 miles) above the moon's surface. This is less than half the distance of Cassini's previous encounter with Enceladus (505 kilometers, 314 miles across), in March of this year. The colored lines delineate the regions that will be imaged at the range of resolutions listed in the legend below. An important scientific goal of this close flyby, during which Cassini will view the moon's previously unseen south pole, will be to search for evidence of geologically recent tectonic or volcanic activity. During the March 2005 Enceladus flyby, Cassini revealed fractures at southern latitudes, which have intriguing spectral differences from the surrounding terrain (see PIA06208). This possibly indicates the presence of coarse-grained ice on the walls of geologically recent, large cracks in the surface. The map was made from images obtained by both the Cassini and Voyager spacecrafts. 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 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 additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
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Zooming In On Enceladus (Mos
…
PIA06254
Saturn
Imaging Science Subsystem -
…
| Title |
Zooming In On Enceladus (Mosaic) |
| Original Caption Released with Image |
As it swooped past the south pole of Saturn's moon Enceladus on July 14, 2005, Cassini acquired high resolution views of this puzzling ice world. From afar, Enceladus exhibits a bizarre mixture of softened craters and complex, fractured terrains. This large mosaic of 21 narrow-angle camera images have been arranged to provide a full-disk view of the anti-Saturn hemisphere on Enceladus. This mosaic is a false-color view that includes images taken at wavelengths from the ultraviolet to the infrared portion of the spectrum, and is similar to another, lower resolution false-color view obtained during the flyby (see PIA06249 [ http://photojournal.jpl.nasa.gov/catalog/PIA06249 ]). In false-color, many long fractures on Enceladus exhibit a pronounced difference in color (represented here in blue) from the surrounding terrain. A leading explanation for the difference in color is that the walls of the fractures expose outcrops of coarse-grained ice that are free of the powdery surface materials that mantle flat-lying surfaces. The original images in the false-color mosaic range in resolution from 350 to 67 meters (1,148 to 220 feet) per pixel and were taken at distances ranging from 61,300 to 11,100 kilometers (38,090 to 6,897 miles) from Enceladus. The mosaic is also part of a movie sequence of images from this flyby (see PIA06253 [ http://photojournal.jpl.nasa.gov/catalog/PIA06253 ]). 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 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 additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
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Tiger Stripes Up Close
PIA06247
Saturn
Imaging Science Subsystem -
…
| Title |
Tiger Stripes Up Close |
| Original Caption Released with Image |
This close-up view of Saturn's moon Enceladus looks toward the moon's terminator (the transition from day to night) and shows a distinctive pattern of continuous, ridged, slightly curved and roughly parallel faults within the moon's southern polar latitudes. These surface features have been informally referred to by imaging scientists as "tiger stripes" due to their distinctly stripe-like appearance when viewed in false color (see PIA06249 [ http://photojournal.jpl.nasa.gov/catalog/PIA06249 ]). Illumination of the scene is from the lower left. The image was obtained in visible light with the Cassini spacecraft narrow-angle camera on July 14, 2005, at a distance of about 20,720 kilometers (12,880 miles) from Enceladus, and at a Sun-Enceladus-spacecraft, or phase, angle of 46 degrees. The image scale is 122 meters (400 feet) per pixel. The image's contrast has been enhanced to aid visibility of surface features. 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 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 additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
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Boulder-Strewn Surface -- Na
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PIA06252
Saturn
Imaging Science Subsystem -
…
| Title |
Boulder-Strewn Surface -- Narrow Angle Camera View |
| Original Caption Released with Image |
The tortured southern polar terrain of Enceladus appears strewn with great boulders of ice in this fantastic view, one of the highest resolution images obtained so far by Cassini of any world. Some smearing of the image due to spacecraft motion is apparent in this scene, which was acquired as Enceladus raced past Cassini's field of view near the time of closest approach. At the time, the imaging cameras were pointed close to the moon's limb (edge), rather than directly below the spacecraft. This allowed for less motion blur than would have been apparent had the cameras pointed straight down. Thus, the terrain imaged here was actually at a distance of 319 kilometers (198 miles) from Cassini. At this fine scale, the surface is dominated by ice blocks between 10 and 100 meters (33 and 330 feet) across. The origin of these icy boulders is enigmatic. Scientists are interested in studying the sizes and numbers of the blocks in this bizarre scene, and in understanding whether terrain covered with boulders is common on Enceladus. A wide-angle camera view centered on this location on Enceladus is available (see PIA06251 [ http://photojournal.jpl.nasa.gov/catalog/PIA06251 ]), as well as a comparison view showing the position of this image within the wide-angle image (see PIA06250 [ http://photojournal.jpl.nasa.gov/catalog/PIA06250 ]). The image was taken during Cassini's very close flyby of Enceladus on July 14, 2005, from a distance of approximately 208 kilometers (129 miles) above Enceladus. Resolution in the image is about 4 meters (13 feet) per pixel. The image has been contrast enhanced to improve the visibility of surface. 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 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 additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
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Craters and Cracks
PIA06248
Saturn
Imaging Science Subsystem -
…
| Title |
Craters and Cracks |
| Original Caption Released with Image |
This dramatic scene from Cassini illustrates an array of processes on Saturn's moon Enceladus, a once geologically active world. Most of the larger craters appear to have softened from their original, presumably crisp appearance, and are cross-cut here by numerous faults. Cassini acquired this high-resolution view of Enceladus during its closest encounter yet with any moon of Saturn. Toward the bottom of the scene, terrain containing fractured and softened craters gives way to essentially non-cratered terrain consisting of tectonic faults. The softened craters, fractured plains and wrinkled terrain on Enceladus suggest geologic activity has taken place in several episodes during the satellite's history. This activity might continue into the present time, although imaging team scientists have seen no evidence for current activity on the moon. Illumination of the scene is from the left. The image was obtained in visible light with the Cassini spacecraft narrow-angle camera on July 14, 2005, at a distance of about 11,500 kilometers (7,150 miles) from Enceladus, and at a Sun-Enceladus-spacecraft, or phase, angle of 46 degrees. The image scale is 67 meters (220 feet) per pixel. The image's contrast has been enhanced to aid visibility of surface features. 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 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 additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
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Boulder-Strewn Surface -- Wi
…
PIA06251
Saturn
Imaging Science Subsystem -
…
| Title |
Boulder-Strewn Surface -- Wide Angle Camera View |
| Original Caption Released with Image |
This wide-angle view is one of the highest resolution images yet acquired by Cassini and shows what appears to be a geologically youthful, tectonically fractured terrain. A higher resolution, narrow-angle view of the center of the terrain shown here is available (see PIA06252 [ http://photojournal.jpl.nasa.gov/catalog/PIA06252 ]), as well as a comparison view showing the position of the narrow-angle image within this image (see PIA06250 [ http://photojournal.jpl.nasa.gov/catalog/PIA06250 ]). The image was taken during Cassini's very close flyby of Enceladus on July 14, 2005, from a distance of approximately 208 kilometers (129 miles) above Enceladus. Resolution in the image is about 37 meters (121 feet) per pixel. The image's contrast has been enhanced to improve the visibility of surface features. 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 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 additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
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Enceladus In False Color
PIA06249
Saturn
Imaging Science Subsystem -
…
| Title |
Enceladus In False Color |
| Original Caption Released with Image |
As Cassini approached the intriguing ice world of Enceladus for its extremely close flyby on July 14, 2005, the spacecraft obtained images in several wavelengths that were used to create this false-color composite view. The surface of Saturn's moon Enceladus shows a range of crater ages, including regions that have very few discernable craters at Cassini's resolution. This observation indicates that there have been multiple episodes of activity on Enceladus spread over some fraction of its history. The resurfacing mechanism appears to be dominated by tectonic fracturing. As of yet, there is no clear evidence for release of liquid to the surface in either icy volcanic flows or geysers. The south polar region (seen here at the lower right) has a distinctive tectonic structure that sets it apart from the rest of the satellite. Its outer boundary is marked by a series of pronounced tectonic "gashes" that form a hoop-like boundary, near 60 degrees south latitude. In this image, this fault zone forms the transition region from the presumably older, cratered terrain in the north to the younger, nearly crater-free region in the south. This false-color view is a composite of individual frames obtained using filters sensitive to ultraviolet (centered at 338 nanometers), green (centered at 568 nanometers) and infrared light (centered at 752 nanometers). The view has been enhanced to accentuate subtle color differences and fine-scale surface features. The Sun illuminates Enceladus from the lower left, leaving part of the moon in shadow. This view shows the anti-Saturn hemisphere, centered at 42 degrees south latitude, 167 west longitude. The images comprising this view were taken with the Cassini spacecraft narrow-angle camera at a distance of about 112,100 kilometers (69,700 miles) from Enceladus, and at a Sun-Enceladus-spacecraft, or phase, angle of 46 degrees. The image scale is about 670 meters (2,200 feet) per pixel. 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 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 additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
|
Zooming In On Enceladus (Mov
…
PIA06253
Saturn
Imaging Science Subsystem -
…
| Title |
Zooming In On Enceladus (Movie) |
| Original Caption Released with Image |
"" Quick Time Movie of Cassini swooping past Saturn?s icy moon Enceladus As it swooped past the south pole of Saturn's moon Enceladus on July 14, 2005, Cassini acquired increasingly high-resolution views of this puzzling ice world. These views have been combined into this exciting movie sequence. The movie provides a stunning, up-close look at what is surely one of the youngest surfaces in the Saturn system. From afar, Enceladus exhibits a bizarre mixture of softened craters and complex, fractured terrains. The movie zooms in on the southern polar terrains and closes in on one of the tectonic stripes that characterize this region which is essentially free of sizeable impact scars. The bright oblong area seen during the zoom is an intermediate resolution image from near the time of closest approach that has been melded into the lower resolution mosaic, and artificially brightened. The movie ends on the highest resolution image acquired by Cassini which reveals a surface dominated by ice blocks between 10 and 100 meters (33 and 330 feet) across, lying in a region that is unusual in its lack of the very fine-grained frost that seems to cover the rest of Enceladus. The lack of frost and the absence of craters are indicators of a youthful surface. The initial image in the movie is a large mosaic of 21 narrow-angle camera images that have been arranged to provide a full-disk view of the anti-Saturn hemisphere on Enceladus. This mosaic is a false-color view that includes images taken at wavelengths from the ultraviolet to the infrared portion of the spectrum, and is similar to another, lower resolution false-color view obtained during the flyby (see PIA06249 [ http://photojournal.jpl.nasa.gov/catalog/PIA06249 ]). In false-color, many long fractures on Enceladus exhibit a pronounced difference in color (represented here in blue) from the surrounding terrain. A leading explanation for the difference in color is that the walls of the fractures expose outcrops of coarse-grained ice that are free of the powdery surface materials that mantle flat-lying surfaces. The original images in the false-color mosaic range in resolution from 350 to 67 meters (1,148 to 220 feet) per pixel and were taken from distances ranging from 61,300 to 11,100 kilometers (38,090 to 6,897 miles) from Enceladus. The mosaic is also available separately (see PIA06254 [ http://photojournal.jpl.nasa.gov/catalog/PIA06254 ], ). Image scale is about 37 meters (121 feet) per pixel in the wide-angle camera image and about 4 meters (13 feet) per pixel in the narrow-angle image (see PIA06250 for these images). Both of these ultra-high resolution views were acquired from an altitude of approximately 208 kilometers (129 miles) above Enceladus as the spacecraft near the time of closest approach during the flyby. 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 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 additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
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Enceladus Keeps the Home Fir
…
PIA09037
Saturn
Composite Infrared Spectrome
…
| Title |
Enceladus Keeps the Home Fires Burning |
| Original Caption Released with Image |
On Nov. 9, 2006, Cassini's composite infrared spectrometer captured its first view of the infrared heat radiation emanating from the "tiger stripe" fractures at the south pole of Saturn's moon Enceladus (right) since the discovery of the hot spot 16 months earlier (left). The original discovery was made just before a close flyby of Enceladus on July 14, 2005, and coincided with the discovery of plumes of water-rich gas and ice particles jetting out of the tiger stripes. However, the spacecraft's orbit did not provide any good views of the south pole for follow-up observations until November 2006. The new observations were made from a range of 110,000 kilometers (68,350 miles), slightly more distant than the 80,000-kilometer range (49,700 miles) of the original observations. Comparison of the two images shows that the south polar region continues to be active, and the distribution of temperatures there has changed little in 16 months. The distribution of heat radiation suggests that most or all of the south polar heat comes from the tiger stripes themselves, though the individual stripes are not resolved at the approximate 30-kilometer (19-mile) spatial resolution of these images. The images show the intensity of heat radiation in the 10- to 16-micron wavelength range, translated into temperature and displayed in false color. Peak south polar temperature on both dates reached about 85 Kelvin (minus 306 degrees Fahrenheit), averaged over the 30-kilometer (19-mile) spatial resolution of the data. However, the variation in brightness with wavelength, which is also measured by the composite infrared spectrometer, reveals that the warm region includes small areas, possibly zones a few 100 meters (320 feet) wide along the length of the tiger stripes, that are at higher temperatures, reaching at least 130 Kelvin (minus 225 degrees Fahrenheit) and perhaps much warmer still. While the south polar tiger stripes are almost certainly heated by energy from the moon's interior, daytime regions at low latitudes are warmed by sunlight to temperatures in the high 70s Kelvin (about minus 320 degrees Fahrenheit). The white numbers on the images show west longitudes on Enceladus, which is 500 kilometers (310 miles) in diameter. The dashed line shows the terminator, the boundary between day and night. The blotchy appearance of the cooler regions away from the south pole, and of the sky beyond the globe of Enceladus, is an artifact resulting from the fact that apart from the polar hot spot, the composite infrared spectrometer can barely detect the very faint heat radiation from this very cold moon. 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, composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/ [ http://saturn.jpl.nasa.gov ]. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/ [ http://cirs.gsfc.nasa.gov/ ]. |
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Enceladus the Storyteller
PIA07800
Saturn
Imaging Science Subsystem -
…
| Title |
Enceladus the Storyteller |
| Original Caption Released with Image |
A masterpiece of deep time and wrenching gravity, the tortured surface of Saturn's moon Enceladus and its fascinating ongoing geologic activity tell the story of the ancient and present struggles of one tiny world. This is a story that is recounted by imaging scientists in a paper published in the journal Science on March 10, 2006. The enhanced color view of Enceladus seen here is largely of the southern hemisphere and includes the south polar terrain at the bottom of the image. Ancient craters remain somewhat pristine in some locales, but have clearly relaxed in others. Northward-trending fractures, likely caused by a change in the moon's rate of rotation and the consequent flattening of the moon's shape, rip across the southern hemisphere. The south polar terrain is marked by a striking set of `blue' fractures and encircled by a conspicuous and continuous chain of folds and ridges, testament to the forces within Enceladus that have yet to be silenced. The mosaic was created from 21 false-color frames taken during the Cassini spacecraft's close approaches to Enceladus on March 9 and July 14, 2005. Images taken using filters sensitive to ultraviolet, visible and infrared light (spanning wavelengths from 338 to 930 nanometers) were combined to create the individual frames. The mosaic is an orthographic projection centered at 46.8 degrees south latitude, 188 degrees west longitude, and has an image scale of 67 meters (220 feet) per pixel. The original images ranged in resolution from 67 meters per pixel to 350 meters (1,150 feet) per pixel and were taken at distances ranging from 11,100 to 61,300 kilometers (6,900 to miles) from Enceladus. 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 imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm [ http://saturn.jpl.nasa.gov ]. The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ]. |
|
Looking Down on Epimetheus
PIA07567
Saturn
Imaging Science Subsystem -
…
| Title |
Looking Down on Epimetheus |
| Original Caption Released with Image |
From 34 degrees above Saturn's equatorial plane, Cassini gazed down at Saturn's moon Epimetheus. The region seen here includes territory farther north and east than that imaged in March 2005 (see PIA06226 [ http://photojournal.jpl.nasa.gov/catalog/PIA06226 ]). The two largest craters visible here are the only officially named features on Epimetheus. The crater at the left (at about the 9 o'clock position) is named Pollux, the crater at lower left (containing a string of several smaller craters) is called Hilairea. Epimetheus is 116 kilometers (72 miles) across. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 14, 2005, at a distance of approximately 87,000 kilometers (54,000 miles) from Epimetheus and at a Sun-Epimetheus-spacecraft, or phase, angle of 95 degrees. The image scale is 520 meters (1,710 feet) per pixel. 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 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 additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
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Enceladus Atmosphere -- Star
…
PIA06431
Saturn
Ultraviolet Imaging Spectrog
…
| Title |
Enceladus Atmosphere -- Star Struck |
| Original Caption Released with Image |
During the July 14, 2005, flyby of Saturn's moon Enceladus, Cassini's ultraviolet imaging spectrograph made the first direct detection of an atmosphere, first suggested by Cassini magnetometer measurements. The ultraviolet imaging spectrograph observed the star Gamma Orionis as Enceladus crossed in front of the star. The light of the star dimmed as it was obscured by the atmosphere before being blocked entirely by Enceladus itself. The spectrum of the starlight changed as it passed through the atmosphere, indicating the presence of water vapor. The ultraviolet imaging spectrograph results suggest that the atmosphere of Enceladus is not constant and may be consistent with a greater amount of atmospheric gas near the south polar region. The presence of water vapor is more consistent with warm water ice than with magnetospheric sputtering. 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 ultraviolet imaging spectrograph was built at, and the team is based at the University of Colorado, Boulder. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. The ultraviolet imaging spectrograph team home page is at http://lasp.colorado.edu/cassini [ http://lasp.colorado.edu/cassini ]. |
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Enceladus Atmosphere (Artist
…
PIA06430
Saturn
Magnetometer
| Title |
Enceladus Atmosphere (Artist's Concept) |
| Original Caption Released with Image |
This artist concept shows the detection of a dynamic atmosphere on Saturn's icy moon Enceladus. The Cassini magnetometer instrument is designed to measure the magnitude and direction of the magnetic fields of Saturn and its moons. During Cassini's three close flybys of Enceladus -- Feb. 17, March 9 and July 14, 2005--the instrument detected a bending of the magnetic field around Enceladus due to electric currents generated by the interaction of atmospheric particles and the magnetosphere of Saturn. The graphic shows the magnetic field observed by Cassini, as well as the predicted neutral cloud being vented from the south pole. Cassini's magnetometer observed bending of the magnetic field consistent with its draping around a conducting object. That indicates that the Saturnian plasma is being diverted away from an extended atmosphere. 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 magnetometer team is based at Imperial College in London, working with team members from the United States and several European countries. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. The magnetometer team homepage is http://www.imperial.ac.uk/research/spat/research/cassini/ [ http://www.imperial.ac.uk/research/spat/research/cassini/ ]. |
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Warm Fractures on Enceladus
PIA06433
Saturn
Composite Infrared Spectrome
…
| Title |
Warm Fractures on Enceladus |
| Original Caption Released with Image |
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 composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/ [ http://cirs.gsfc.nasa.gov/ ]. The imaging team homepage is at http://ciclops.org [ http://ciclops.org ], This image shows the warmest places in the south polar region of Saturn's moon Enceladus. The unexpected temperatures were discovered by Cassini's composite infrared spectrometer during a close flyby on July 14, 2005. The image shows how these temperatures correspond to the prominent, bluish fractures dubbed "tiger stripes," first imaged by Cassini's imaging science subsystem cameras. Working together the two teams were able to pinpoint the exact location of the warmest regions on Enceladus. The composite infrared spectrometer instrument measured the infrared heat radiation from the surface at wavelengths between 9 and 16.5 microns within each of the 10 squares shown here. Each square is 6 kilometers (4 miles) across. The color of each square, and the number shown above it, describe the composite infrared spectrometer's measurement of the approximate average temperature of the surface within that square. The warmest temperature squares, at 91 and 89 degrees Kelvin (minus 296 and minus 299 degrees Fahrenheit), are located over one of the "tiger stripe" fractures. They contrast sharply with the surrounding temperatures, which are in the range 74 to 81 degrees Kelvin (minus 326 to minus 313 degrees Fahrenheit). The detailed composite infrared spectrometer data suggest that small areas near the fracture are at substantially higher temperatures, well over 100 degrees Kelvin (minus 279 degrees Fahrenheit). Such "warm" temperatures are unlikely to be due to heating of the surface by the feeble sunlight striking Enceladus' south pole. They are a strong indication that internal heat is leaking out of Enceladus and warming the surface along these fractures. Evaporation of this relatively warm ice probably generates the cloud of water vapor detected above Enceladus' south pole by several other Cassini instruments. Scientists are unsure how the internal heat reaches the surface. The process might involve liquid water, slushy brine, or soft but solid ice. The imaging science subsystem image is an enhanced color view with a pixel scale of 122 meters (400 feet) that was acquired at the same time as the composite infrared spectrometer data. It covers a region 125 kilometers (75 miles) across. The spacecraft's distance from Enceladus was 21,000 kilometers (13,000 miles). The broad bluer fractures that can be seen running from the upper left to the lower right of the image are 1 to 2 kilometers (0.6 to 1.2 miles) wide and more than 100 kilometers (60 miles) long. The fractures are thought to be bluer than the surrounding surface because coarser-grained ice (which has a blue color just as thick masses of ice, like glaciers and icebergs, do on Earth) has been exposed in the fractures. The color image was constructed using an ultraviolet filter (centered at 338 nanometers) in the blue channel, a clear filter in the green channel, and an infrared filter (centered at 930 nanometers) in the red channel. The Cassini-Huygens mission is a cooperative project of |
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Rhea: Polar View
PIA07566
Saturn
Imaging Science Subsystem -
…
| Title |
Rhea: Polar View |
| Original Caption Released with Image |
Like the rest of Rhea's surface, the southern polar region of this Saturn moon has been extensively re-worked by cratering over the eons. This close-up shows that most sizeable craters have smaller, younger impact sites within them. Near the left lies an intriguing gash. The largest well-defined crater visible here is an oval-shaped impact toward the upper right. The crater is 115 by 91 kilometers (71 by 57 miles) in size. Cassini acquired this view during a distant flyby of Rhea (1,528 kilometers, or 949 miles across) on July 14, 2005. The image was taken in visible light with the Cassini spacecraft narrow-angle camera at a distance of approximately 239,000 kilometers (149,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 56 degrees. The image was obtained using a filter sensitive to wavelengths of infrared light centered at 930 nanometers. The image scale is about 1 kilometer (0.6 miles) per pixel. 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 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 additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
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Enceladus Temperature Map
PIA06432
Saturn
Composite Infrared Spectrome
…
| Title |
Enceladus Temperature Map |
| Original Caption Released with Image |
. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/ [ http://cirs.gsfc.nasa.gov/ ]., This image shows the surprise that startled Cassini scientists on the composite infrared spectrometer team when they got their first look at the infrared (heat) radiation from the south pole of Saturn's moon Enceladus. There is a dramatic warm spot centered on the pole that is probably a sign of internal heat leaking out of the icy moon. The data were taken during the spacecraft's third flyby of this intriguing moon on July 14, 2005. Based on data from previous flybys, which did not show the south pole well, team members expected that the south pole would be very cold, as shown in the left panel. Enceladus is one of the coldest places in the Saturn system because its extremely bright surface reflects 80 percent of the sunlight that hits it, so only 20 percent is available to heat the surface. As on Earth, the poles should be even colder than the equator because the sun shines at such an oblique angle there. The right hand panel shows a global temperature image made from measurements of Enceladus' heat radiation at wavelengths between 9 and 16.5 microns. Cassini made the observation from a distance of 84,000 kilometers (52,000 miles) on the approach to Enceladus, and the image shows details as small as 25 kilometers (16 miles). Equatorial temperatures are much as expected, topping out at about 80 degrees Kelvin (-315 degrees Fahrenheit), but the south pole is occupied by a well-defined warm region reaching 85 Kelvin (-305 degrees Fahrenheit). That is 15 degrees Kelvin (27 degrees Fahrenheit) warmer than expected. The composite infrared spectrometer data further suggest that small areas of the pole are at even higher temperatures, well over 110 degrees Kelvin (-261 degrees Fahrenheit). Evaporation of this relatively warm ice probably generates the cloud of water vapor detected above Enceladus' south pole by several other Cassini instruments. The south polar temperatures are very difficult to explain if sunlight is the only energy source heating the surface, though exotic sunlight-trapping mechanisms have not yet been completely ruled out. It therefore seems likely that portions of the polar region are warmed by heat escaping from the interior of the moon. This would make Enceladus only the third solid body in the solar system, after Earth and Jupiter's volcanic moon Io, where hot spots powered by internal heat have been detected. 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 composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ] |
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Above Rhea's South Pole
PIA07572
Saturn
Imaging Science Subsystem -
…
| Title |
Above Rhea's South Pole |
| Original Caption Released with Image |
Cassini looks upward at the south polar region on Rhea during a recent distant encounter. Rhea's icy surface is so heavily saturated with impact craters that the moon's limb, or edge, has a rugged, bumpy appearance. Rhea is 1,528 kilometers (949 miles) across. The bright splotch seen here near the upper right is impact material (or ejecta) from a relatively fresh crater (see PIA06648 [ http://photojournal.jpl.nasa.gov/catalog/PIA06648 ] for another view of this bright feature). The image was taken with the Cassini spacecraft narrow-angle camera on July 14, 2005, at a distance of approximately 342,000 kilometers (212,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 36 degrees. The image was obtained using a filter sensitive to wavelengths of infrared light centered at 298 nanometers. The image scale is 2 kilometers (1 mile) per pixel. 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 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 additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
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