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Titan (T25) Viewed by Cassin
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| Description |
Titan (T25) Viewed by Cassini's Radar Feb. 22, 2007 |
| Full Description |
This image of Saturn's largest moon, Titan, obtained by Cassini's radar instrument during a near-polar flyby on Feb. 22, 2007, features dunes and lakes, one of which is larger than any lake on Earth and could be legitimately called a sea. First discovered by Cassini's radar in July 2006 (see Lakes on Titan), Titan's lakes are thought to consist of liquid methane and ethane. The image runs from southern latitudes, starting at 32 degrees south, 55 degrees west, where we see featureless terrain with bright streaks, heading north and slightly east, through dune fields interspersed with exposed bright mounds. In places, the dunes wrap around the bright mounds, which suggests the mounds are raised (see Titan Features and Interactions). In one case, the dunes wrap around an unusual rose-shaped structure, approximately 70 kilometers (40 miles) across. Near the spacecraft's closest approach (33 degrees north, 28 degrees west), where the swath is at its narrowest, the terrain is dark and mottled, with occasional bright outcrops and fine dunes. As we continue to head north, we see the first signs of the action of liquids -- fine channels and canyon-like structures. Later, depressions can be seen. These are similar to those seen in the lake region and are interpreted as volcanic calderas or drained lakes. As the swath continues, these become more plentiful, and some are partly filled with dark material thought to be liquid hydrocarbons, hence lakes. In places, the lakes reside in what appear to be nested, near-circular depressions, reminiscent of nested calderas. The final section of the swath, which is closest to the pole, contains by far the largest lakes observed by Cassini's radar to date. Part of the first of these was seen during a previous flyby (see Titan's Great Lakes?), and is fed by a long river -- over 200 kilometers (120 miles) in length, and hundreds of meters to over 1 kilometer (0.6 miles) in width - running through what appears to be a flood plain. The lake's bright, jutting shoreline indicates that old, eroded landforms may have been flooded. The end of the next lake was also observed before (see Lakes and More lakes), appearing to be, in both form and scale, similar to Lake Powell, a flooded drainage system in Utah and Arizona. We can now see that this lake on Titan connects via a relatively narrow channel to a much larger (at least 45,000 square kilometers or 17,000 square miles) lake, containing a large (approximately 12,000 square kilometers or 4,600 square miles) island or peninsula (see Titan: Larger and Larger Lakes). The last part of the image passes close to the pole (86 degrees north, 290 degrees east), before heading east and slightly south. At the end of the swath, we see the largest lake observed yet -- at least 100,000 square kilometers (39,000 square miles), which is greater in extent than one of the largest lakes on Earth, Lake Superior (82,000 square kilometers or 32,000 square miles), and covers a greater fraction of, Titan than the largest terrestrial inland sea, the Black Sea. The Black Sea covers 0.085 percent of the surface of the Earth, this newly observed body on Titan covers at least 0.12 percent of the surface of Titan. Because of its size, scientists are calling this a sea. 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 radar instrument was built by JPL and the Italian Space Agency, 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/home/index.cfm. *Credit:* NASA/JPL |
| Date |
March 13, 2007 |
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Saturn's Strange Hexagon
| Description |
This is one of the first clear images taken of the north polar region ever acquired from a unique polar perspective. |
| Full Description |
This nighttime view of Saturn's north pole by the visual and infrared mapping spectrometer onboard NASA's Cassini orbiter clearly shows a bizarre six-sided hexagon feature encircling the entire north pole. This is one of the first clear images taken of the north polar region ever acquired from a unique polar perspective. In this image, the red color indicates the amount of 5-micron wavelength radiation, or heat, generated in the warm interior of Saturn that escapes the planet. Clouds near 3-bar (about 100 kilometers or 62 miles deeper than seen in visible wavelengths) block the light, revealing them in silhouette against the background thermal glow of Saturn. The bluish color shows sunlight striking the far limb (edge) of the planet, showing that the entire north pole is under the nighttime conditions characteristic of polar winter, as on Earth. This image is the first to capture the entire feature and north polar region in one shot, and is also the first polar view using Saturn's thermal glow at 5 microns (seven times the wavelength visible to the human eye) as the light source. This allows the pole to be revealed during the persistent nighttime conditions under way during winter. The hexagon feature was originally discovered by NASA's Voyager spacecraft in 1980, but those historic images and subsequent ground-based telescope images suffered from poor viewing perspectives, which placed the feature and the north pole at the extreme northern limb (edge) in those images. In the new infrared images, the strong brightness of the hexagon feature indicates that it is primarily a clearing in the clouds, which extends deep into the atmosphere, at least some 75 kilometers (47 miles) underneath the typical upper hazes and clouds seen in the daytime imagery by Voyager. Thick clouds border both sides of the narrow feature, as indicated by the adjacent dark lanes paralleling the bright hexagon. This and other images acquired over a 12-day period between Oct. 30 and Nov. 11, 2006, show that the feature is nearly stationary, and likely is an unusually strong pole-encircling planetary wave that extends deep into the atmosphere. This image was acquired with the Cassini visual and infrared mapping spectrometer on Oct. 30, 2006, from an average distance of 1.3 million kilometers (807,782 miles). 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, where this image was produced. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm. The visual and infrared mapping spectrometer team homepage is at, http://wwwvims.lpl.arizona.edu. Credit: NASA/JPL/University of Arizona |
| Date |
March 27, 2007 |
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Saturn's North Pole Hexagon
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| Description |
Clearly revealed is the bizarre six-sided hexagon feature present at the north pole of Saturn. |
| Full Description |
Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm. The visual and infrared mapping spectrometer team homepage is at http://wwwvims.lpl.arizona.edu. Credit: NASA/JPL/University of Arizona, This nighttime view of Saturn's north pole by the visual and infrared mapping spectrometer on NASA's Cassini orbiter reveals a dynamic, active planet at least 75 kilometers (47 miles) below the normal cloud tops seen in visible light. Clearly revealed is the bizarre six-sided hexagon feature present at the north pole. This image is one of the first clear images of the north polar region ever acquired from a unique polar perspective. In this image, the blue color shows high-altitude emissions from atmospheric molecules excited by charged particles smashing into the atmosphere along Saturn's powerful magnetic field lines, producing the aurora at very high altitudes in Saturn's atmosphere. The red color indicates the amount of 5-micron wavelength radiation, or heat, generated in the depths of the warm interior of Saturn that escapes the planet. Clouds blocking this light are revealed as silhouettes against the background thermal glow of the planet. This image is among the first to capture the entire hexagonal feature and north polar region in one shot. It is also one of the first polar views using Saturn's thermal glow at 5 microns (seven times the wavelength visible to the human eye) as the light source. This allows polar cloud features to be revealed during the persistent nighttime conditions under way during north polar winter. The hexagonal feature was originally discovered by NASA's Voyager spacecraft in 1980, but those images and subsequent ground-based telescope images suffered from poor viewing perspectives, which placed the feature and the north pole at the extreme northern limb (edge) in those images. The strong brightness of the hexagon feature indicates that it is primarily a clearing in the clouds, which extends deep into the atmosphere, at least down to the 3-bar (3-Earth atmospheres pressure) level, about 75 kilometers (47 miles) below the clouds and hazes seen in visible wavelengths. Thick clouds border both sides of the narrow feature, as indicated by the adjacent dark lanes paralleling the bright hexagon. This image and other images acquired over a 12-day period between Oct. 30 and Nov. 11, 2006, show that the feature is nearly stationary, and likely is an unusually strong pole-encircling planetary wave that extends deep into the atmosphere. This image was acquired by the Cassini visual and infrared mapping spectrometer on Oct. 29, 2006, from an average distance of 905,000 kilometers (562,340 miles) above the clouds. 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, where this image was produced. For more information about the |
| Date |
March 27, 2007 |
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Neon Saturn
| Description |
Neon Saturn |
| Full Description |
Flying over the unlit side of Saturn's rings, the Cassini spacecraft captures Saturn's glow, represented in brilliant shades of electric blue, sapphire and mint green, while the planet's shadow casts a wide net on the rings. This striking false-color mosaic was created from 25 images taken by Cassini's visual and infrared mapping spectrometer over a period of 13 hours, and captures Saturn in nighttime and daytime conditions. The visual and infrared mapping spectrometer acquires data simultaneously at 352 different wavelengths, or spectral channels. Data at wavelengths of 2.3, 3.0 and 5.1 microns were combined in the blue, green and red channels of a standard color image, respectively, to make this false-color mosaic. This image was acquired on Feb. 24, 2007, while the spacecraft was 1.58 million kilometers (1 million miles) from the planet and 34.6 degrees above the ring plane. The solar phase angle was 69.5 degrees. In this view, Cassini was looking down on the northern, unlit side of the rings, which are rendered visible by sunlight filtering through from the sunlit, southern face. On the night side (right side of image), with no sunlight, Saturn's own thermal radiation lights things up. This light at 5.1 microns wavelength (some seven times the longest wavelength visible to the human eye) is generated deep within Saturn, and works its way upward, eventually escaping into space. Thick clouds deep in the atmosphere block that light. An amazing array of dark streaks, spots, and globe-encircling bands is visible instead. Saturn's strong thermal glow at 5.1 microns even allows these deep clouds to be seen on portions of the dayside (left side), especially where overlying hazes are thin and the glint of the sun off of them is minimal. These deep clouds are likely made of ammonium hydrosulfide and cannot be seen in reflected light on the dayside, since the glint of the sun on overlying hazes and ammonia clouds blocks the view of this level. A pronounced difference in the brightness between the northern and southern hemispheres is apparent. The northern hemisphere is about twice as bright as the southern hemisphere. This is because high-level, fine particles are about half as prevalent in the northern hemisphere as in the south. These particles block Saturn's glow more strongly, making Saturn look brighter in the north. At 2.3 microns (shown in blue), the icy ring particles are highly reflecting, while methane gas in Saturn's atmosphere strongly absorbs sunlight and renders the planet very dark. At 3.0 microns (shown in green), the situation is reversed: water ice in the rings is strongly absorbing, while the planet's sunlit hemisphere is bright. Thus the rings appear blue in this representation, while the sunlit side of Saturn is greenish-yellow in color. Within the rings, the most opaque parts appear dark, while the more translucent regions are brighter. In particular, the opaque, normally-bright B ring appears here as a broad, dark band, separating the brighter A (outer) and C (inner) rings. At 5.1 microns (shown in red), reflected sunlight is weak and thus light from the planet is dominated by thermal (i.e., heat) radiation that wells up from the planet's deep atmosphere. This thermal emission dominates Saturn's dark side as well as the north polar region (where the hexagon is again visible) and the shadow cast by the A and B rings. Variable amounts of clouds in the planet's upper atmosphere block the thermal radiation, leading to a speckled and banded appearance, which is ever-shifting due to the planet's strong winds. 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, where this image was produced. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm. The visual and infrared mapping spectrometer team homepage is at http://wwwvims.lpl.arizona.edu. *Credit:* NASA/JPL/University of Arizona |
| Date |
May 31, 2007 |
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Cat's eye rings and peek-a-b
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| Description |
On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. |
| Full Description |
Astronomers have long known that Saturn's rings reflect sunlight most strongly when Earth is located directly between Saturn and the sun. Flat, shiny surfaces (like a mirror or a pond) can appear particularly bright when light reflects off them in a certain direction. Scientists call this "specular reflection," from the Latin word for mirror. However, even rough surfaces, like those of Earth's moon or Saturn's rings, can appear bright when the source of light is directly behind the observer's head, no matter what the orientation of the surface is. This latter phenomenon is known as the "opposition effect." Spectacular examples include the eyes of a cat, which seem to glow brightly when they are illuminated by a flashlight, or highway signs and reflectors that "light up" when they are caught in a car's headlights. On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. Combined here into a mosaic, the images show -- from left to right -- a small, bright spot moving from the outermost B ring across the Cassini Division and all the way across the A ring. In each image, this spot is centered on the point in the rings directly opposite the sun. Theoretical models for the opposition effect suggest that it can be explained by light being scattered several times within the surfaces of individual, transparent, icy ring particles on scales of about 40 micrometers, or 1/500th of an inch. Similar effects are seen in laboratory studies of bright, finely-textured material such as snow or sugar crystals. In this mosaic, blue colors highlight the icy rings (2.35 microns), green represents sunlight reflected by the clouds of Saturn (2.86 microns) and red depicts thermal emission from the planet's interior (5.02 microns). The rings were observed while they were in front of the planet, producing a complex interplay of sunlight reflected from the rings and the shadows cast by the rings on the cloud tops of Saturn. The yellow-green sunlit clouds of Saturn are seen in the upper right corner of the mosaic beyond the outer edge of the A ring, and also through the 4,000-kilometer-wide (2,400 mile) Cassini Division in the left third of the mosaic. (Yellow indicates a mixture of reflected sunlight and thermal emission.) The shadowed regions of the planet, on the other hand, appear deep red because only thermal emission produced deep inside Saturn itself is visible. At exact opposition, the shadows of the rings are hidden behind the rings themselves, but away from this point shadows can be seen peeking out from behind the edges of the A and B rings into the Cassini Division, as well as beyond the outer edge of the A ring. If one looks closely, one can even trace the A ring's shadow behind the partly transparent A ring, as a faint purple band. Within this band, a thin blue-green line crossing obliquely behind the A ring is, caused by sunlight passing through the narrow Encke Gap in the outer A ring. The Cassini spacecraft was at a distance of 254,000 kilometers (157,800 miles) from the center of Saturn when these images were taken, while the opening angle of the rings to the sun was 16.3 degrees. The image scale at the rings is approximately 70 kilometers (40 miles) per pixel. All nine images were taken over a period of 27 minutes, and the vertical dimension of the mosaic is 1.8 degrees. 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, where this image was produced. For more information about the Cassini-Huygens mission, visit: http://saturn.jpl.nasa.gov/home/index.cfm. The visual and infrared mapping spectrometer team home page is at: http://wwwvims.lpl.arizona.edu . Credit: NASA/JPL/University of Arizona |
| Date |
June 26, 2007 |
|
Cat's eye rings and peek-a-b
…
| Description |
On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. |
| Full Description |
See also the non-annotated version. Astronomers have long known that Saturn's rings reflect sunlight most strongly when Earth is located directly between Saturn and the sun. Flat, shiny surfaces (like a mirror or a pond) can appear particularly bright when light reflects off them in a certain direction. Scientists call this "specular reflection," from the Latin word for mirror. However, even rough surfaces, like those of Earth's moon or Saturn's rings, can appear bright when the source of light is directly behind the observer's head, no matter what the orientation of the surface is. This latter phenomenon is known as the "opposition effect." Spectacular examples include the eyes of a cat, which seem to glow brightly when they are illuminated by a flashlight, or highway signs and reflectors that "light up" when they are caught in a car's headlights. On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. Combined here into a mosaic, the images show -- from left to right -- a small, bright spot moving from the outermost B ring across the Cassini Division and all the way across the A ring. In each image, this spot is centered on the point in the rings directly opposite the sun. Theoretical models for the opposition effect suggest that it can be explained by light being scattered several times within the surfaces of individual, transparent, icy ring particles on scales of about 40 micrometers, or 1/500th of an inch. Similar effects are seen in laboratory studies of bright, finely-textured material such as snow or sugar crystals. In this mosaic, blue colors highlight the icy rings (2.35 microns), green represents sunlight reflected by the clouds of Saturn (2.86 microns) and red depicts thermal emission from the planet's interior (5.02 microns). The rings were observed while they were in front of the planet, producing a complex interplay of sunlight reflected from the rings and the shadows cast by the rings on the cloud tops of Saturn. The yellow-green sunlit clouds of Saturn are seen in the upper right corner of the mosaic beyond the outer edge of the A ring, and also through the 4,000-kilometer-wide (2,400 mile) Cassini Division in the left third of the mosaic. (Yellow indicates a mixture of reflected sunlight and thermal emission.) The shadowed regions of the planet, on the other hand, appear deep red because only thermal emission produced deep inside Saturn itself is visible. At exact opposition, the shadows of the rings are hidden behind the rings themselves, but away from this point shadows can be seen peeking out from behind the edges of the A and B rings into the Cassini Division, as well as beyond the outer edge of the A ring. If one looks closely, one can even trace the A ring's shadow behind the partly transparent A ring, as a faint purple band. Within this band, a thin blue-green line, crossing obliquely behind the A ring is caused by sunlight passing through the narrow Encke Gap in the outer A ring. The Cassini spacecraft was at a distance of 254,000 kilometers (157,800 miles) from the center of Saturn when these images were taken, while the opening angle of the rings to the sun was 16.3 degrees. The image scale at the rings is approximately 70 kilometers (40 miles) per pixel. All nine images were taken over a period of 27 minutes, and the vertical dimension of the mosaic is 1.8 degrees. 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, where this image was produced. For more information about the Cassini-Huygens mission, visit: http://saturn.jpl.nasa.gov/home/index.cfm. The visual and infrared mapping spectrometer team home page is at: http://wwwvims.lpl.arizona.edu . Credit: NASA/JPL/University of Arizona |
| Date |
June 26, 2007 |
|
Organics Sprinkled on Hyperi
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| Description |
Organics Sprinkled on Hyperion |
| Full Description |
Hyperion, the eighth largest of Saturn's nearly 60 known moons, is covered in craters and landslides. Sprinkled over the icy surface is a thin layer of organic dust, which has somehow been concentrated in the bottoms of some of the craters, forming a reddish black deposit. This new color map shows the composition of a portion of Hyperion's surface determined with the Visual and Infrared Mapping Spectrometer aboard the Cassini spacecraft. The new composition map is overlaid onto a previously released Cassini image of Hyperion, taken with the Imaging Science Subsystem (see Cosmic Blasting Zone). Blue shows the maximum exposure of frozen water, red denotes carbon dioxide ice ("dry ice"), magenta indicates regions of water plus carbon dioxide, yellow is a mix of carbon dioxide and an unidentified material. Discovered in 1848, Hyperion held its secrets until the Cassini spacecraft flew close in September 2005, revealing its icy and organic composition. Hyperion is irregular in shape, tumbles chaotically, and takes 21 days to orbit Saturn. It is 300 kilometers (180 miles) in its longest dimension. 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. 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. The visual and infrared mapping spectrometer team home page is at: http://wwwvims.lpl.arizona.edu . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/University of Arizona/Ames/Space Science Institute |
| Date |
July 4, 2007 |
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Hyperion's Kaleidoscope of C
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| Description |
Hyperion's Kaleidoscope of Color |
| Full Description |
This is a color map of the composition of a portion of Saturn's moon Hyperion's surface about 75 kilometers (45 miles) on a side. In this map, blue shows the maximum exposure of frozen water, red denotes carbon dioxide ice ("dry ice"), magenta indicates regions of water plus carbon dioxide, yellow is a mix of carbon dioxide and an unidentified material. This map was made with data from the Visual and Infrared Mapping Spectrometer aboard the Cassini spacecraft during its flyby of Hyperion in September 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. 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. The visual and infrared mapping spectrometer team home page is at: http://wwwvims.lpl.arizona.edu . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/University of Arizona/Ames/Space Science Institute |
| Date |
July 4, 2007 |
|
Iapetus' Equatorial Region -
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| Description |
Iapetus' Equatorial Region -- Labeled |
| Full Description |
Cassini made a close flyby of Saturn's moon Iapetus on Sept. 10, 2007, and the visual and infrared mapping spectrometer obtained these images during that event. These two images show a higher resolution version of the equatorial region shown in Tiny Grains on Iapetus. The equatorial region includes the equatorial bulge which shows no differences in these compositions compared to surrounding regions. The color image on the right shows the results of mapping for three components of Iapetus' surface: carbon dioxide that is trapped or adsorbed in the surface (red), water in the form of ice (green), and a newly-discovered effect due to trace amount of dark particles in the ice creating what scientists call Rayleigh scattering (blue). The Rayleigh scattering effect is the main reason why the Earth's sky appears blue. There is a complex transition zone from the dark region, on the right, which is high in carbon dioxide, to the more ice-rich region on the left. Some crater floors are filled with carbon dioxide-rich dark material. As the ice becomes cleaner to the left, the small dark particles become more scattered and increase the Rayleigh scattering effect, again indicative of less than 2 percent dark sub-0.5-micron particles. The visual and infrared mapping spectrometer is like a digital camera, but instead of using three colors, it makes images in 352 colors, or wavelengths, from the ultraviolet to the near-infrared. The many wavelengths produce a continuous spectrum in each pixel, and these spectra measure how light is absorbed by different materials. By analyzing the absorptions expressed in each pixel, a map of the composition at each location on the moon can be constructed. 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/home/index.cfm. The visual and infrared mapping spectrometer team home page is at: http://wwwvims.lpl.arizona.edu. Credit: NASA/JPL/University of Arizona /USGS |
| Date |
October 8, 2007 |
|
Tiny Grains on Iapetus
| Description |
Tiny Grains on Iapetus |
| Full Description |
Cassini made a close flyby of Saturn's moon Iapetus on Sept. 10, 2007, and the visual and infrared mapping spectrometer obtained these images showing surface composition and particle size. The visual and infrared mapping spectrometer is like a digital camera, but instead of using three colors, it makes images in 352 colors, or wavelengths, from the ultraviolet to the near-infrared. The many wavelengths produce a continuous spectrum in each pixel, and these spectra measure how light is absorbed by different materials. By analyzing the absorptions expressed in each pixel, a map of the composition at each location on the moon can be constructed. The left image in the figure shows the amount of reflected light at a wavelength of 1.75 microns in the infrared (green light seen by our eyes is 0.53 microns). The color image on the right shows the results of mapping for three components of Iapetus' surface: carbon dioxide that is trapped or adsorbed in the surface (red), water in the form of ice (green), and a newly-discovered effect due to trace amount of dark particles in the ice creating what scientists call Rayleigh scattering (blue). The Rayleigh scattering effect is the main reason why the Earth's sky appears blue. The Rayleigh scattering effect on Iapetus provides evidence that tiny grains, less than the wavelength of visible light (less than 0.5 microns) have been embedded in the surface of Iapetus. The tiny grains must be well-separated for the Rayleigh effect to become prominent, so the abundance of particles must be less than about 2 percent. The Rayleigh scattering effect shows in all areas, although weakly in dark regions (the red carbon dioxide dominates the color image), and it appears stronger away from the equator. Investigating the trend from dark to bright areas, the Rayleigh effect changes with the amount of dark material in the ice, and becomes weaker as more dark material is added. This points to cleaner ice as one moves north or south from the equator and away from the dark leading side of the moon (toward the right in the image). This provides additional evidence for an external source for the dark material coating Iapetus, and for ice transport away from the warm dark regions and equator to the cooler poles. The ice transport away from the equator increases the concentration of dark material there and reduces the Rayleigh effect. With the volatile transport from the dark warm regions, the strong carbon dioxide signature is a surprise because frozen carbon dioxide is more volatile than water ice. Therefore, the carbon dioxide must be trapped, making its presence stable in the warm equatorial region. The trapping mechanism is currently under study. 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/home/index.cfm. The visual and infrared mapping spectrometer team home page is at: http://wwwvims.lpl.arizona.edu. Credit: NASA/JPL/University of Arizona/USGS |
| Date |
October 8, 2007 |
|
Titan's Giant North Pole Clo
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| Description |
Titan's Giant North Pole Cloud |
| Full Description |
Cassini's visual and infrared mapping spectrometer has imaged a huge cloud system covering the north pole of Titan. This composite image shows the cloud, imaged at a distance of 90,000 kilometers (54,000 miles) during a Dec. 29, 2006, flyby designed to observe the limb of the moon. Cassini's visual and infrared mapping spectrometer scanned the limb, revealing this spectacular cloud system. It covers the north pole down to a latitude of 62 degrees north and at all observed longitudes. Such a cloud cover was expected, according to the atmospheric circulation models of Titan, but it had never been observed before with such details. The condensates may be the source of liquids that fill the lakes recently discovered by the radar instrument. This image was color-coded, with blue, green and red at 2 microns, 2.7, and 5 microns, respectively. 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 where this image was produced. 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 |
February 1, 2007 |
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Hubble Probes Layer-cake Str
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| Title |
Hubble Probes Layer-cake Structure of Alien World's Atmosphere |
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Hubble Probes Layer-cake Str
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| Title |
Hubble Probes Layer-cake Structure of Alien World's Atmosphere |
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Hubble Probes Layer-cake Str
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| Title |
Hubble Probes Layer-cake Structure of Alien World's Atmosphere |
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Hubble Sees 'Comet Galaxy' B
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| Title |
Hubble Sees 'Comet Galaxy' Being Ripped Apart By Galaxy Cluster |
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The Carina Nebula: Star Birt
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| Title |
The Carina Nebula: Star Birth in the Extreme |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. In celebration of the 17th anniversary of the launch and deployment of NASA's Hubble Space Telescope, a team of astronomers is releasing one of the largest panoramic images ever taken with Hubble's cameras. READ: Junior version of this article Amazing Space Learn about this story in the Star Witness, a science newspaper available on our sister site, Amazing Space. [ http://amazing-space.stsci.edu/news/archive/2007/02/ ] It is a 50-light-year-wide view of the central region of the Carina Nebula where a maelstrom of star birth —, and death —, is taking place. This image is a mosaic of the Carina Nebula assembled from 48 frames taken with Hubble's Advanced Camera for Surveys. The Hubble images were taken in the light of neutral hydrogen during March and July 2005. Color information was added with data taken in December 2001 and March 2003 at the Cerro Tololo Inter-American Observatory in Chile. Red corresponds to sulfur, green to hydrogen, and blue to oxygen emission. |
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Hubble Images of Asteroids H
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| Title |
Hubble Images of Asteroids Help Astronomers Prepare for Spacecraft Visit |
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Hubble and Spitzer Space Tel
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| Title |
Hubble and Spitzer Space Telescopes Find "Lego-Block" Galaxies in Early Universe |
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Hubble and Spitzer Space Tel
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| Title |
Hubble and Spitzer Space Telescopes Find "Lego-Block" Galaxies in Early Universe |
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Hubble and Spitzer Space Tel
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| Title |
Hubble and Spitzer Space Telescopes Find "Lego-Block" Galaxies in Early Universe |
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Hubble and Spitzer Space Tel
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| Title |
Hubble and Spitzer Space Telescopes Find "Lego-Block" Galaxies in Early Universe |
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Hubble and Spitzer Space Tel
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| Title |
Hubble and Spitzer Space Telescopes Find "Lego-Block" Galaxies in Early Universe |
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Hubble Images of Asteroids H
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| Title |
Hubble Images of Asteroids Help Astronomers Prepare for Spacecraft Visit |
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Hubble and Spitzer Space Tel
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| Title |
Hubble and Spitzer Space Telescopes Find "Lego-Block" Galaxies in Early Universe |
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Hubble Images of Asteroids H
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| Title |
Hubble Images of Asteroids Help Astronomers Prepare for Spacecraft Visit |
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Hubble and Spitzer Space Tel
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| Title |
Hubble and Spitzer Space Telescopes Find "Lego-Block" Galaxies in Early Universe |
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Hubble Images of Asteroids H
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| Title |
Hubble Images of Asteroids Help Astronomers Prepare for Spacecraft Visit |
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Heatwave in Southern Califor
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| Title |
Heatwave in Southern California |
| Description |
September 5, 2007, marked the end of a week-long heat wave that led to 31 deaths and triggered power outages across southern California, reported the L.A. Times. Temperatures climbed above 38 degrees Celsius (100 Fahrenheit) when a high-pressure system blocked cool air from the Pacific. The effect of the heat wave on different locations in the Southwest is shown in this pair of images, taken on September 5, at 11:25 a.m. local time (18:25 UTC) by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) flying on NASA's Terra [ http://terra.nasa.gov/ ], in Northern California filters down from the top edge of the scene. NASA image created by Jesse Allen, using data obtained from the Goddard Land Processes data archives (LAADS). [ http://laads.gsfc.nasa.gov/ ], satellite. The photo-like, natural-color image (top) and corresponding land surface temperature image (bottom) illustrate the relationship between land cover, elevation, and temperature. The images show much of California and Nevada, and a smaller portion of Arizona and Utah. Not surprisingly, the hottest areas, shown in yellow, correspond with sparsely vegetated desert regions. In the natural-color image, the brush-covered Mojave Desert on the California-Nevada border is tan with splashes of pink where iron-rich sandstone is exposed. The small-leafed, woody vegetation provides little shade, allowing the Earth's surface to be exposed to the Sun. The rock-and-dirt desert absorbs sunlight, and temperatures climb (yellow areas of bottom image). The other hot spots in the image occur in the cactus-dotted Sonoran Desert, which encompasses the southernmost portions of inland California and southwestern Arizona, and the much smaller Colorado Desert west of the Salton Sea. Irrigated land south of the Salton Sea and along the Colorado River is a web of brown-green. The presence of water and vegetation in these irrigated areas makes the land cooler. Elevation also plays a role in the surface temperatures of the Sonoran Desert. Pockets of low-elevation land are much warmer than the lines of mountains that separate them, particularly in southwestern Arizona. The coolest parts of California, shown in purple and blue, are in the mountains, most prominently the Sierra Nevada, but also the San Bernardino Mountains east of Los Angeles. In the photo-like images, the mountain ranges are dark green, colored by trees. The vegetation cover and the high elevation keep the land cooler than surrounding low-elevation sites. The other significant cool spot in the image is the San Joaquin Valley. Like the irrigated farm land bordering the Salton Sea and the Colorado River, this area is kept cool by the presence of water and plants. The coldest areas in the image appear to be in Arizona, Utah, and Nevada, which are marked by streaks of dark purple. These cold signatures are from clouds.The final correlation between land cover and temperature can be seen in urban areas along the coast. In the photo-like image, Los Angles sprawls as a silver-gray patch from the coast to the San Bernardino Mountains. Since urban surfaces absorb heat, Los Angles is slightly warmer in the surface temperature image than the surrounding landscape. In the north, the San Francisco urban area is similarly warmer than its surroundings. Though the extreme temperatures raised the fire danger in Southern California, MODIS did not detect any fires in the region. Fires, marked with red dots, were burning in Central California south and east of San Francisco. Smoke from a large fire [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14497 ] |
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Drought in Southwestern Unit
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| Title |
Drought in Southwestern United States |
| Description |
The southwestern United States pined for water in late March and early April 2007. This image is based on data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite from March 22 through April 6, 2007, and it shows the Normalized Difference Vegetation Index, or NDVI, for the period. In this NDVI color scale, green indicates areas of healthier-than-usual vegetation, and only small patches of green appear in this image, near the California-Nevada border and in Utah. Larger areas of below-normal vegetation are more common, especially throughout California. Pale yellow indicates areas with generally average vegetation. Gray areas appear where no data were available, likely due to persistent clouds or snow cover. According to the April 10, 2007, update from the U.S. Drought Monitor, [ http://www.drought.unl.edu/dm/monitor.html ] most of the southwestern United Sates, including Utah, Nevada, California, and Arizona, experienced moderate to extreme drought. The hardest hit areas were southeastern California and southwestern Arizona. Writing for the Drought Monitor, David Miskus of the Joint Agricultural Weather Facility reported that March 2007 had been unusually dry for the southwestern United States. While California's and Utah's reservoir storage was only slightly below normal, reservoir storage was well below normal for New Mexico and Arizona. In early April, an international research team published an online paper in Science noting that droughts could become more common for the southwestern United States and northern Mexico, as these areas were already showing signs of drying. Relying on the same computer models used in the Intergovernmental Panel on Climate Change (IPCC) report released in early 2007, the researchers who published in Science concluded that global warming could make droughts more common, not just in the American Southwest, but also in semiarid regions of southern Europe, Mediterranean northern Africa, and the Middle East. NASA image created by Jesse Allen, Earth Observatory, using data provided by Inbal Reshef, Global Agricultural Monitoring Project [ http://www.pecad.fas.usda.gov/glam.cfm ]. |
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Fires Across the Western Uni
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| Title |
Fires Across the Western United States |
| Description |
Days of record heat made the western United States tinder dry in early July 2007. Numerous wildfires raced across the dry terrain during the weekend of July 7. From Washington to Arizona, firefighters were battling fast-moving wildfires that threatened residences, businesses, gas wells, coal mines, communications equipment, and municipal watersheds. This image of the West was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite on Sunday, July 8. Places where MODIS detected actively burning fires are marked in red. Some of the largest blazes are labeled. Utah's Milford Flat was the largest, according to the July 9 morning report from the National Interagency Fire Center, [ http://www.nifc.gov/information.html ] the blaze was more than 280,000 acres, having grown more than 124,000 acres in the previous 24 hours. The fires have destroyed homes, forced evacuations, shut down trains and highways, and killed several people. Weather conditions were not expected to improve significantly across much of the area for several days, with hot temperatures and dry thunderstorms (lightning and winds, but little rain) likely in many places. Nearly the entire western United States was experiencing some level of drought as of July 3, according to the U.S. Drought Monitor. [ http://www.drought.unl.edu/dm/monitor.html ] The drought had reached the "extreme" category in southern California and western Arizona, and ranged from moderate to severe across most of the rest of the Southwest and Great Basin. The large image provided above has a spatial resolution (level of detail) of 500 meters per pixel. The MODIS Rapid Response Team provides twice-daily [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?USA1/ ] images of the region in additional resolutions and formats, including an infrared-enhanced version that makes burned terrain appear brick red. NASA image courtesy the MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center |
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Fires Across Western United
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| Title |
Fires Across Western United States |
| Description |
Days of record heat made the western United States tinder dry in early July 2007. Numerous wildfires raced across the dry terrain during the weekend of July 7. From Washington to Arizona, firefighters were battling fast-moving wildfires that threatened residences, businesses, gas wells, coal mines, communications equipment, and municipal watersheds. This image of the West was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite on Sunday, July 8. Places where MODIS detected actively burning fires are marked in red. Some of the largest blazes are labeled. Utah's Milford Flat was the largest, according to the July 9 morning report from the National Interagency Fire Center, [ http://www.nifc.gov/information.html ] the blaze was more than 280,000 acres, having grown more than 124,000 acres in the previous 24 hours. The fires have destroyed homes, forced evacuations, shut down trains and highways, and killed several people. Weather conditions were not expected to improve significantly across much of the area for several days, with hot temperatures and dry thunderstorms (lightning and winds, but little rain) likely in many places. Nearly the entire western United States was experiencing some level of drought as of July 3, according to the U.S. Drought Monitor. [ http://www.drought.unl.edu/dm/monitor.html ] The drought had reached the "extreme" category in southern California and western Arizona, and ranged from moderate to severe across most of the rest of the Southwest and Great Basin. The large image provided above has a spatial resolution (level of detail) of 500 meters per pixel. The MODIS Rapid Response Team provides twice-daily [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?USA1/ ] images of the region in additional resolutions and formats, including an infrared-enhanced version that makes burned terrain appear brick red. NASA image courtesy the MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center |
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Drought in Southwestern Unit
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nasa, nasaimageofthedaygalle
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The southwestern United Stat
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swusandvia_tmo_2007081
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-04-06 |
| creator |
NASA -- NASA image created by Jesse Allen, Earth Observatory, using data provided by Inbal Reshef, www.pecad.fas.usda.gov/glam.cfm Global Agricultural Monitoring Project . |
| identifier |
swusandvia_tmo_2007081 |
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Heatwave in Southern Califor
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nasa, nasanaturalhazards
September 5, 2007, marked th
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california_tmo_2007248_lst_l
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| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-09-05 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
california_tmo_2007248_lst_lrg |
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Heatwave in Southern Califor
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nasa, nasanaturalhazards
September 5, 2007, marked th
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california_tmo_2007248_lst_l
…
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-09-05 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
california_tmo_2007248_lst_lrg |
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Winds Blow Smoke in Californ
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nasa, nasaimageofthedaygalle
…
In addition to the dangers t
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aerosols_omi_2007297
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-10-24 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
aerosols_omi_2007297 |
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Fires Across the Western Uni
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nasa, nasaimageofthedaygalle
…
Days of record heat made the
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West_fires_TMO_2007189
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-07-08 |
| creator |
NASA -- NASA image courtesy the rapidfire.sci.gsfc.nasa.gov MODIS Rapid Response Team, Goddard Space Flight Center |
| identifier |
West_fires_TMO_2007189 |
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Heat Wave in Southern Califo
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nasa, nasaimageofthedaygalle
…
September 5, 2007, marked th
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ge_08024
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-09-05 |
| creator |
NASA -- NASA image created by Jesse Allen, using data obtained from the laads.gsfc.nasa.gov/ Goddard Land Processes data archives (LAADS). |
| identifier |
ge_08024 |
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Heat Wave in Southern Califo
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nasa, nasaimageofthedaygalle
…
September 5, 2007, marked th
…
ge_08024
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-09-05 |
| creator |
NASA -- NASA image created by Jesse Allen, using data obtained from the laads.gsfc.nasa.gov/ Goddard Land Processes data archives (LAADS). |
| identifier |
ge_08024 |
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Ares Vallis Cataract
PIA09683
Sol (our sun)
HiRISE
| Title |
Ares Vallis Cataract |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image (PSP_003538_1885 [ http://hirise.lpl.arizona.edu/PSP_003538_1885 ]) shows a dry cataract within Ares Vallis. A cataract is a large waterfall where there is a high, steep drop. The presence of this large cataract in Ares Vallis confirms that this channel was carved by water, probably in one or many large catastrophic flooding events. This feature has many of the same characteristics as the cataracts on Earth associated with the flood that carved the Channelled Scablands in Washington state, including horseshoe-shaped headcuts and longitudinal grooves. These grooves in the lower portion of the image lead up to the cataract, with the water flowing from the south to the north in this image. It then flowed down the cataract into the smaller incised channel. The horseshoe-shaped headcut here is only part of a larger cataract system, and probably formed during the last stage of flooding. The inner channels are now filled with dunes formed by wind blowing along the channel floor. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:28 PMDegrees latitude (centered): 8.4° Degrees longitude (East): 335.6° Range to target site: 276.0 km (172.5 miles) Original image scale range: 27.6 cm/pixel (with 1 x 1 binning) so objects ~83 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 1.3° Phase angle: 56.9° Solar incidence angle: 58°, with the Sun about 32° above the horizon Solar longitude: 228.1°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Ares Vallis Cataract
PIA09683
Sol (our sun)
HiRISE
| Title |
Ares Vallis Cataract |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image (PSP_003538_1885 [ http://hirise.lpl.arizona.edu/PSP_003538_1885 ]) shows a dry cataract within Ares Vallis. A cataract is a large waterfall where there is a high, steep drop. The presence of this large cataract in Ares Vallis confirms that this channel was carved by water, probably in one or many large catastrophic flooding events. This feature has many of the same characteristics as the cataracts on Earth associated with the flood that carved the Channelled Scablands in Washington state, including horseshoe-shaped headcuts and longitudinal grooves. These grooves in the lower portion of the image lead up to the cataract, with the water flowing from the south to the north in this image. It then flowed down the cataract into the smaller incised channel. The horseshoe-shaped headcut here is only part of a larger cataract system, and probably formed during the last stage of flooding. The inner channels are now filled with dunes formed by wind blowing along the channel floor. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:28 PMDegrees latitude (centered): 8.4° Degrees longitude (East): 335.6° Range to target site: 276.0 km (172.5 miles) Original image scale range: 27.6 cm/pixel (with 1 x 1 binning) so objects ~83 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 1.3° Phase angle: 56.9° Solar incidence angle: 58°, with the Sun about 32° above the horizon Solar longitude: 228.1°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Slope Streak South of Olympu
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PIA09685
Sol (our sun)
HiRISE
| Title |
Slope Streak South of Olympus Mons |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image (PSP_003239_1870 [ http://hirise.lpl.arizona.edu/PSP_003239_1870 ]) reveals slope streaks in an area south of Olympus Mons in the northern hemisphere of Mars. These features are found along the slopes of impact craters, buttes, knobs, ridges, and troughs on Mars. Streaks generally start at a point source and widen downslope, traveling over and sometimes around various obstacles. The subimage [ http://photojournal.jpl.nasa.gov/figures/PIA09685_fig2.jpg ], shows a very wide dark slope that has developed small fingers at its terminus. The dark slope streak does not appear to have relief and does not disturb the pre-existing surface leaving the underlying topography intact beneath its dark trail. This can be seen particularly well near the streak termination. There are also no observable deposits of displaced materials along the terminus. Surrounding the dark slope streak are multiple ~1 meter deep, triangular faceted scars left behind from avalanched slope materials. The high standing remnant surfaces on either side of the lower scarred surface are clearly visible. Avalanche scars are sometimes found in areas where slope streaks have formed but they are believed to be unrelated. The trail of the dark slope streak appears to cross over the avalanche scars suggesting that the slope streak formed more recently. Slope streak formation is among the few known processes currently active on Mars. While their mechanism of formation and triggering is debated, they are most commonly believed to form by downslope movement of extremely dry sand or very fine-grained dust in an almost fluidlike manner (analogous to a terrestrial snow avalanche) exposing darker underlying material. Other ideas include the triggering of slope streak formation by possible concentrations of near-surface ice or scouring of the surface by running water from aquifers intercepting slope faces, briny liquid flows, dry granular flow, mixed water-dust flows, and/or hydrothermal activity. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:35 PM Degrees latitude (centered): 7.1° Degrees longitude (East): 218.2° Range to target site: 274.5 km (171.6 miles) Original image scale range: 54.9 cm/pixel (with 2 x 2 binning) so objects ~165 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 4.2° Phase angle: 61.3° Solar incidence angle: 57°, with the Sun about 33° above the horizon Solar longitude: 213.6°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Slope Streak South of Olympu
…
PIA09685
Sol (our sun)
HiRISE
| Title |
Slope Streak South of Olympus Mons |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image (PSP_003239_1870 [ http://hirise.lpl.arizona.edu/PSP_003239_1870 ]) reveals slope streaks in an area south of Olympus Mons in the northern hemisphere of Mars. These features are found along the slopes of impact craters, buttes, knobs, ridges, and troughs on Mars. Streaks generally start at a point source and widen downslope, traveling over and sometimes around various obstacles. The subimage [ http://photojournal.jpl.nasa.gov/figures/PIA09685_fig2.jpg ], shows a very wide dark slope that has developed small fingers at its terminus. The dark slope streak does not appear to have relief and does not disturb the pre-existing surface leaving the underlying topography intact beneath its dark trail. This can be seen particularly well near the streak termination. There are also no observable deposits of displaced materials along the terminus. Surrounding the dark slope streak are multiple ~1 meter deep, triangular faceted scars left behind from avalanched slope materials. The high standing remnant surfaces on either side of the lower scarred surface are clearly visible. Avalanche scars are sometimes found in areas where slope streaks have formed but they are believed to be unrelated. The trail of the dark slope streak appears to cross over the avalanche scars suggesting that the slope streak formed more recently. Slope streak formation is among the few known processes currently active on Mars. While their mechanism of formation and triggering is debated, they are most commonly believed to form by downslope movement of extremely dry sand or very fine-grained dust in an almost fluidlike manner (analogous to a terrestrial snow avalanche) exposing darker underlying material. Other ideas include the triggering of slope streak formation by possible concentrations of near-surface ice or scouring of the surface by running water from aquifers intercepting slope faces, briny liquid flows, dry granular flow, mixed water-dust flows, and/or hydrothermal activity. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:35 PM Degrees latitude (centered): 7.1° Degrees longitude (East): 218.2° Range to target site: 274.5 km (171.6 miles) Original image scale range: 54.9 cm/pixel (with 2 x 2 binning) so objects ~165 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 4.2° Phase angle: 61.3° Solar incidence angle: 57°, with the Sun about 33° above the horizon Solar longitude: 213.6°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Faults and Folds in Western
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PIA09682
Sol (our sun)
HiRISE
| Title |
Faults and Folds in Western Candor Chasma |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image (PSP_003540_1735 [ http://hirise.lpl.arizona.edu/PSP_003540_1735 ]) shows various interesting structures along the floor of Candor Chasma, a major canyon of Valles Marineris. The rocks along the floor of the chasma consist of multiple layers of light-toned material, possibly windblown or water-lain sediment. These layers have been shifted along faults and also folded, giving the layers an apparent wavy appearance as they are exposed at the surface through erosion. Some waviness in the layers may also have formed as these sediments were laid down, for example, in dunes or large ripples. Detailed mapping of these faults and folds may help reveal the origin of these layered deposits and if water played any role in their formation. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:33 PM Degrees latitude (centered): -6.4° Degrees longitude (East): 283.2° Range to target site: 263.6 km (164.7 miles) Original image scale range: 26.4 cm/pixel (with 1 x 1 binning) so objects ~79 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 7.3° Phase angle: 46.0° Solar incidence angle: 53°, with the Sun about 37° above the horizon Solar longitude: 228.2°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Faults and Folds in Western
…
PIA09682
Sol (our sun)
HiRISE
| Title |
Faults and Folds in Western Candor Chasma |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image (PSP_003540_1735 [ http://hirise.lpl.arizona.edu/PSP_003540_1735 ]) shows various interesting structures along the floor of Candor Chasma, a major canyon of Valles Marineris. The rocks along the floor of the chasma consist of multiple layers of light-toned material, possibly windblown or water-lain sediment. These layers have been shifted along faults and also folded, giving the layers an apparent wavy appearance as they are exposed at the surface through erosion. Some waviness in the layers may also have formed as these sediments were laid down, for example, in dunes or large ripples. Detailed mapping of these faults and folds may help reveal the origin of these layered deposits and if water played any role in their formation. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:33 PM Degrees latitude (centered): -6.4° Degrees longitude (East): 283.2° Range to target site: 263.6 km (164.7 miles) Original image scale range: 26.4 cm/pixel (with 1 x 1 binning) so objects ~79 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 7.3° Phase angle: 46.0° Solar incidence angle: 53°, with the Sun about 37° above the horizon Solar longitude: 228.2°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Layers in Galle Crater
PIA09686
Sol (our sun)
HiRISE
| Title |
Layers in Galle Crater |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image shows part of a large mass of layered rock in Galle Crater, in the southern cratered highlands of Mars. At low resolution, layers appear as bands and swirls which are nearly horizontal. This causes them to interact dramatically with topography, producing the appearance of folds and loops wrapping around small hills much like lines on a contour map. Zooming in at higher resolution, some long cracks (hundreds of meters long) are cutting across the layers, generally trending northeast-southwest. At full resolution (PSP_002655_1280 [ http://hirise.lpl.arizona.edu/PSP_002655_1280 ]), details of the layers are often obscured by ripples of wind-blown dust or textured patterns of erosion now eroding the rock. In the best exposures, such as that in the cutout section, the layers are fractured into blocks. Some of the layers are relatively resistant, and appear as ridges or fins in the cutout, often with little material supporting them from below. Although this seems to indicate relatively strong, coherent material, few boulders are visible. The ridge-forming layers may be weak, but separated by material with virtually no cohesion. Polygonal fracture patterns in the dark regolith between distinct layers could be due to ground ice, or regional tectonic stresses. Observation Toolbox Acquisition date: 2 February 2007 Local Mars time: 3:54 PM Degrees latitude (centered): -51.8° Degrees longitude (East): 330.0° Range to target site: 256.3 km (160.2 miles) Original image scale range: 25.6 cm/pixel (with 1 x 1 binning) so objects ~77 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 2.8° Phase angle: 71.5° Solar incidence angle: 69°, with the Sun about 21° above the horizon Solar longitude: 186.6°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Layers in Galle Crater
PIA09686
Sol (our sun)
HiRISE
| Title |
Layers in Galle Crater |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image shows part of a large mass of layered rock in Galle Crater, in the southern cratered highlands of Mars. At low resolution, layers appear as bands and swirls which are nearly horizontal. This causes them to interact dramatically with topography, producing the appearance of folds and loops wrapping around small hills much like lines on a contour map. Zooming in at higher resolution, some long cracks (hundreds of meters long) are cutting across the layers, generally trending northeast-southwest. At full resolution (PSP_002655_1280 [ http://hirise.lpl.arizona.edu/PSP_002655_1280 ]), details of the layers are often obscured by ripples of wind-blown dust or textured patterns of erosion now eroding the rock. In the best exposures, such as that in the cutout section, the layers are fractured into blocks. Some of the layers are relatively resistant, and appear as ridges or fins in the cutout, often with little material supporting them from below. Although this seems to indicate relatively strong, coherent material, few boulders are visible. The ridge-forming layers may be weak, but separated by material with virtually no cohesion. Polygonal fracture patterns in the dark regolith between distinct layers could be due to ground ice, or regional tectonic stresses. Observation Toolbox Acquisition date: 2 February 2007 Local Mars time: 3:54 PM Degrees latitude (centered): -51.8° Degrees longitude (East): 330.0° Range to target site: 256.3 km (160.2 miles) Original image scale range: 25.6 cm/pixel (with 1 x 1 binning) so objects ~77 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 2.8° Phase angle: 71.5° Solar incidence angle: 69°, with the Sun about 21° above the horizon Solar longitude: 186.6°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Evros Vallis and Nearby Crat
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PIA09684
Sol (our sun)
HiRISE
| Title |
Evros Vallis and Nearby Craters |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image (PSP_003273_1675 [ http://hirise.lpl.arizona.edu/PSP_003273_1675 ]) shows part of Evros Vallis, one of the Martian valley networks. These more ancient valley networks may have been eroded by flowing water during a warmer, wetter period of Martian history. Many dunes are visibile along the valley floor, as well as throughout the scene and in a partially exhumed crater on the valley wall. There are multiple generations and orientations of dunes. Dune orientation reflects the dominant or prevailing wind direction. Multiple dune orientations indicate that this region has experienced different wind regimes. An exhumed crater is one that likely formed a long time ago, was buried, and is now being re-exposed because the materials that originally covered it are being eroded away. The prominent crater on the valley wall as well as several other craters in this scene are thought to be partially exhumed. The subimage [ http://photojournal.jpl.nasa.gov/figures/PIA09684_fig2.jpg ] (approximately 300 m across) shows a couple groups of secondary craters. Secondary craters are craters that form when ejecta from the primary crater hits the surface with enough energy to form another smaller crater. As seen in the subimage, secondary craters often form in clusters spatially, because ejecta thrown out of the primary crater impacts the surface near each other at approximately the same time. Many potential secondary craters have have similar morphologies and have distinct, bright ejecta. This implies that these craters are relatively young and that their ejecta have yet to be covered by dust. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:41 PM Degrees latitude (centered): -12.6° Degrees longitude (East): 13.3° Range to target site: 264.3 km (165.2 miles) Original image scale range: 26.4 cm/pixel (with 1 x 1 binning) so objects ~79 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 7.6° Phase angle: 46.2° Solar incidence angle: 54°, with the Sun about 36° above the horizon Solar longitude: 215.3°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Evros Vallis and Nearby Crat
…
PIA09684
Sol (our sun)
HiRISE
| Title |
Evros Vallis and Nearby Craters |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image (PSP_003273_1675 [ http://hirise.lpl.arizona.edu/PSP_003273_1675 ]) shows part of Evros Vallis, one of the Martian valley networks. These more ancient valley networks may have been eroded by flowing water during a warmer, wetter period of Martian history. Many dunes are visibile along the valley floor, as well as throughout the scene and in a partially exhumed crater on the valley wall. There are multiple generations and orientations of dunes. Dune orientation reflects the dominant or prevailing wind direction. Multiple dune orientations indicate that this region has experienced different wind regimes. An exhumed crater is one that likely formed a long time ago, was buried, and is now being re-exposed because the materials that originally covered it are being eroded away. The prominent crater on the valley wall as well as several other craters in this scene are thought to be partially exhumed. The subimage [ http://photojournal.jpl.nasa.gov/figures/PIA09684_fig2.jpg ] (approximately 300 m across) shows a couple groups of secondary craters. Secondary craters are craters that form when ejecta from the primary crater hits the surface with enough energy to form another smaller crater. As seen in the subimage, secondary craters often form in clusters spatially, because ejecta thrown out of the primary crater impacts the surface near each other at approximately the same time. Many potential secondary craters have have similar morphologies and have distinct, bright ejecta. This implies that these craters are relatively young and that their ejecta have yet to be covered by dust. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:41 PM Degrees latitude (centered): -12.6° Degrees longitude (East): 13.3° Range to target site: 264.3 km (165.2 miles) Original image scale range: 26.4 cm/pixel (with 1 x 1 binning) so objects ~79 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 7.6° Phase angle: 46.2° Solar incidence angle: 54°, with the Sun about 36° above the horizon Solar longitude: 215.3°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Dark Slope Streak with Strea
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PIA09681
Sol (our sun)
HiRISE
| Title |
Dark Slope Streak with Streak-Generated Topography |
| Original Caption Released with Image |
Click on image for larger version This is a portion of HiRISE image PSP_003542_2035 [ http://hirise.lpl.arizona.edu/PSP_003542_2035 ] which shows a dark slope streak north of Olympus Mons, in a region was covered by Mars Orbital Camera image R09/00701. (This portion is rotated with south up so that the direction the streak flowed is towards the bottom of the frame). This image shows that the slope streak forming process altered the pre-existing surface both by excavating material and depositing it. The fine scalloped texture of the surrounding surface is not present within the streak, and there are low linear mounds within the streak that are not seen outside. Their absence outside the streak indicates that the formation of the mounds resulted from the streak formation process. There is a large boulder or knob within the streak near the top of the frame which the dark slope streak appears to have flowed around, leaving a light-toned patch of the surrounding surface material intact downstream of the boulder. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:22 PM Degrees latitude (centered): 23.3° Degrees longitude (East): 223.7° Range to target site: 285.3 km (178.3 miles) Original image scale range: 28.5 cm/pixel (with 1 x 1 binning) so objects ~86 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 7.6° Phase angle: 71.6° Solar incidence angle: 65°, with the Sun about 25° above the horizon Solar longitude: 228.3°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Dark Slope Streak with Strea
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PIA09681
Sol (our sun)
HiRISE
| Title |
Dark Slope Streak with Streak-Generated Topography |
| Original Caption Released with Image |
Click on image for larger version This is a portion of HiRISE image PSP_003542_2035 [ http://hirise.lpl.arizona.edu/PSP_003542_2035 ] which shows a dark slope streak north of Olympus Mons, in a region was covered by Mars Orbital Camera image R09/00701. (This portion is rotated with south up so that the direction the streak flowed is towards the bottom of the frame). This image shows that the slope streak forming process altered the pre-existing surface both by excavating material and depositing it. The fine scalloped texture of the surrounding surface is not present within the streak, and there are low linear mounds within the streak that are not seen outside. Their absence outside the streak indicates that the formation of the mounds resulted from the streak formation process. There is a large boulder or knob within the streak near the top of the frame which the dark slope streak appears to have flowed around, leaving a light-toned patch of the surrounding surface material intact downstream of the boulder. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:22 PM Degrees latitude (centered): 23.3° Degrees longitude (East): 223.7° Range to target site: 285.3 km (178.3 miles) Original image scale range: 28.5 cm/pixel (with 1 x 1 binning) so objects ~86 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 7.6° Phase angle: 71.6° Solar incidence angle: 65°, with the Sun about 25° above the horizon Solar longitude: 228.3°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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