|
|
Missouri River TOPSAR
This is a combined radar and
…
11/6/95
| Date |
11/6/95 |
| Description |
This is a combined radar and topography image of an area along the Missouri River that experienced severe flooding and levee failure in the summer of 1993. The meandering course of the Missouri River is seen as the dark curving band on the left side of the image. The predominantly blue area on the left half of the image is the river's flood plain, which was completely inundated during the flood of 1993. The colors in the image represent elevations, with the low areas shown in purple, intermediate areas in blue, green and yellow, and the highest areas shown in orange. The total elevation range is 85 meters (279 feet). The higher yellow and orange area on the right side of the image shows the topography and drainage patterns typical of this part of the midwestern United States. Dark streaks and bands in the flood plain are agricultural areas that were severely damaged by levee failures during the flooding. The region enclosed by the C-shaped bend in the river in the upper part of the image is Lisbon Bottoms. A powerful outburst of water from a failed levee on the north side of Lisbon Bottoms scoured a deep channel across the fields, which shows up as purple band. As the flood waters receded, deposits of sand and silt were left behind, which now appear as dark, smooth streaks in the image. The yellow areas within the blue, near the river, are clumps of trees sitting on slightly higher ground within the flood plain. The radar "sees' the treetops, and that is why they are so much higher (yellow) than the fields. The image was acquired by the NASA/JPL Topographic Synthetic Aperture Radar system (TOPSAR) that flew over the area aboard a DC-8 aircraft in August 1994. The elevations are obtained by a technique known as radar interferometry, in which the radar signals are transmitted by one antenna, and echoes are received by two antennas aboard the aircraft. The two sets of received signals are combined using computer processing to produce a topographic map. Similar techniques can be used to map the Earth's topography from satellites and from the space shuttle. The brightness of the image represents the radar backscatter at C-band, in the vertically transmitted and received polarization. The image is centered south of the town of Glasgow in central Missouri, at 39.1 degrees north latitude and 92.9 degrees west longitude. The area shown is about 5 km by 10 km (3.1 by 6.2 miles). Radar and topography data such as these are being used by scientists to more accurately assess the potential for future flooding in this region and how that might impact surrounding communities. Radar and interferometry processing for this image was performed at JPL, image generation was performed at Washington University, St. Louis. |
|
Boston, Massachusetts
This radar image of the area
…
11/16/95
| Date |
11/16/95 |
| Description |
This radar image of the area surrounding Boston, Mass., shows how a spaceborne radar system distinguishes between densely populated urban areas and nearby areas that are relatively unsettled. The bright white area at the right center of the image is downtown Boston. The wide river below and to the left of the city is the Charles River in Boston's Back Bay neighborhood. The dark green patch to the right of the Back Bay is Boston Common. A bridge across the north end of Back Bay connects the cities of Boston and Cambridge. The light green areas that dominate most of the image are the suburban communities surrounding Boston. The many ponds that dot the region appear as dark irregular spots. Many densely populated urban areas show up as red in the image due to the alignment of streets and buildings to the incoming radar beam. North is toward the upper left. The image was acquired on October 9, 1994, by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) as it flew aboard the space shuttle Endeavour. This area is centered at 42.4 degrees north latitude, 71.2 degrees west longitude. The area shown is approximately 37 km by 18 km (23 miles by 11 miles). Colors are assigned to different radar frequencies and polarizations as follows: red is L-band horizontally transmitted, horizontally received, green is L-band horizontally transmitted, vertically received, blue is C-band horizontally transmitted, vertically received. SIR-C/X-SAR, a cooperative mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program. ##### |
|
Belgrade, Serbia L & C bands
This spaceborne radar image
…
5/9/96
| Date |
5/9/96 |
| Description |
This spaceborne radar image of Belgrade, Serbia, illustrates the variety of land use patterns that can be observed with a multiple wavelength radar system. Belgrade, the capital of Serbia and former capital of Yugoslavia, is the bright area in the center of the image. The Danube River flows from the top to the bottom of the image, and the Sava River flows into the Danube from the left. Agricultural fields appear in shades of dark blue, purple and brown in outlying areas. Vegetated areas along the rivers appear in light blue-green, while dense forests in hillier areas in the lower left appear in a darker shade of green. The image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on October 2, 1994. The image is centered at 44.5 degrees north latitude and 20.5 degrees east longitude. North is toward the upper right. The image shows an area 36 kilometers by 32 kilometers (22 miles by 20 miles). The colors are assigned to different frequencies and polarizations of the radar as follows: red is L- band, horizontally transmitted, horizontally received, green is L-band, horizontally transmitted, vertically received, blue is C-band, horizontally transmitted, vertically received. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program. ##### |
|
SRTM/Swath Comparison
This image shows a 40-kilome
…
7/15/96
| Date |
7/15/96 |
| Description |
This image shows a 40-kilometer (25-mile) wide strip of digital topographic data superimposed on an optical photograph of the western United States. Both images were acquired during the STS-68 flight in October 1994. The digital data were acquired by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture radar system, while the photograph was taken by the Space Shuttle astronauts. The view is looking to the east from above California's central valley (the dark area seen at the bottom of the image) across the snow-covered Sierra Nevada Mountains to the basin and range province of western Nevada. In the strip of topographic data, the different colors indicate elevation, with green being lowest and white being highest. The swath covers blue-colored Lake Tahoe on the left (north) and Mono Lake on the right. For comparison, the white lines indicate the 225- kilometer (140-mile) wide swath that will be mapped in a single pass by the Shuttle Radar Topography Mapper (SRTM) instrument, now scheduled to fly on the Space Shuttle in May 2000. The ability to cover a swath this wide will allow SRTM to completely map all the land surface between plus and minus 60 degrees latitude in a single 11-day flight. This is about 80% of Earth's total land area. SRTM, is a cooperative project between NASA and the Defense Mapping Agency of the U.S. Department of Defense that will be managed by the Jet Propulsion Laboratory for NASA's Office of Mission to Planet Earth. ##### |
|
Munich, Germany L & C bands
This spaceborne radar image
…
7/11/96
| Date |
7/11/96 |
| Description |
This spaceborne radar image of Munich, Germany illustrates the capability of a multi-frequency radar system to highlight different land use patterns in the area surrounding Bavaria's largest city. Central Munich is the white area at the middle of the image, on the banks of the Isar River. Pink areas are forested, while green areas indicate clear-cut and agricultural terrain. The Munich region served as a primary "supersite" for studies in ecology, hydrology and radar calibration during the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR- C/X-SAR) missions. Scientists were able to use these data to map patterns of forest damage from storms and areas affected by bark beetle infestation. The image was acquired by SIR-C/X-SAR onboard the space shuttle Endeavour on April 18, 1994. The image is 37 kilometers by 32 kilometers (23 miles by 20 miles) and is centered at 48.2 degrees North latitude, 11.5 degrees East longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations of the radar as follows: red is L-band, vertically transmitted and horizontally received, green is C-band, vertically transmitted and horizontally received, and blue is C-band vertically transmitted and received. SIR-C/X-SAR, a joint mission of the German, Italian, and United States space agencies, is part of NASA's Mission to Planet Earth. ##### |
|
Mississippi River L, C bands
This image of the Mississipp
…
5/25/95
| Date |
5/25/95 |
| Description |
This image of the Mississippi River in Mississippi, Arkansas, and Louisiana shows regions of the southern United States that are prone to flooding. Data acquired by the Spaceborne Imaging Radar- C/X-band Synthetic Aperture imaging radar system, which flew on two space shuttle missions in April and October 1994, can help scientists assess flooding potentials and improve land management for future agricultural development. This image was acquired on October 9,1994, during orbit 151 of the space shuttle Endeavour. The image is centered at about 32.75 degrees north latitude and 90.5 degrees west longitude and covers an area of about 23 kilometers by 40 kilometers (14.2 miles by 24.8 miles). North is toward the upper right of the image. The different colors represent the data return in different radar channels: red is L- band, vertically transmitted and received, green is L-band vertically transmitted and horizontally received, and blue is C- band vertically transmitted and received. This site along the Mississippi River lies north of Vicksburg along the Arkansas- Louisiana-Mississippi state borders. The river marks the stateline. Louisiana and Arkansas lie above the river and Mississippi is below the river. This region is characterized by rich farmland where a variety of crops are grown. The town located in the extreme upper left hand corner is Eudora, Arkansas. The long,narrow lakes which lie roughly parallel to the river are called oxbow lakes, named for the U-shaped harness worn by an ox. Oxbows are formed when a river changes course, abandoning old channels in favor of a new course. As the river changes course, the surrounding land dries out, leaving these lakes isolated. Oxbow lakes are common in areas where rivers flow through generally flat terrain, allowing the river to easily change course. The green regions bordering the river are undeveloped forested areas. |
|
Lakes on Titan
| Description |
These two radar images were acquired by the Cassini radar instrument in synthetic aperture mode on July 21, 2006. |
| Full Description |
The Cassini spacecraft, using its radar system, has discovered very strong evidence for hydrocarbon lakes on Titan. Dark patches, which resemble terrestrial lakes, seem to be sprinkled all over the high latitudes surrounding Titan's north pole. Scientists have speculated that liquid methane or ethane might form lakes on Titan, particularly near the somewhat colder polar regions. In the images, a variety of dark patches, some with channels leading in or out of them, appear. The channels have a shape that strongly implies they were carved by liquid. Some of the dark patches and connecting channels are completely black, that is, they reflect back essentially no radar signal, and hence must be extremely smooth. In some cases rims can be seen around the dark patches, suggesting deposits that might form as liquid evaporates. The abundant methane in Titan's atmosphere is stable as a liquid under Titan conditions, as is its abundant chemical product, ethane, but liquid water is not. For all these reasons, scientists interpret the dark areas as lakes of liquid methane or ethane, making Titan the only body in the solar system besides Earth known to possess lakes. Because such lakes may wax and wane over time, and winds may alter the roughness of their surfaces. Repeat coverage of these areas should test whether indeed these are bodies of liquid. These two radar images were acquired by the Cassini radar instrument in synthetic aperture mode on July 21, 2006. The top image centered near 80 degrees north, 92 degrees west measures about 420 kilometers by 150 kilometers (260 miles by 93 miles). The lower image centered near 78 degrees north, 18 degrees west measures about 475 kilometers by 150 kilometers (295 miles by 93 miles). Smallest details in this image are about 500 meters (1,640 feet) across. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The 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 . *Credit:* NASA/JPL |
| Date |
July 24, 2006 |
|
Titan's Great Lakes?
| Description |
Titan's Great Lakes? |
| Full Description |
Using its radar system, the Cassini spacecraft has imaged new lakes on Titan. The large dark patch seen on this image, at high latitudes surrounding Titan's north pole, is most likely a hydrocarbon lake. Several dark channels can be seen, the longest one at the left meanders over almost 100 kilometers (62 miles), and appears to drain into the lake. Some dark channels are remarkably straight, suggesting possible faulting in the subsurface. The bright landforms jutting into the lake indicate that old, eroded landforms may have flooded. For a different radar view from the same flyby see Lakes and more lakes. This radar image was acquired by the Cassini radar instrument in synthetic aperture mode on Oct. 9, 2006. The image is centered near 73 degrees north latitude, 343 degrees west longitude, and measures about 300 kilometers by 140 kilometers (190 miles by 90 miles). Smallest details in this image are about 500 meters (1,640 feet) across. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The radar instrument team is based at JPL, working with team members from the United States and several European countries. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. Credit: NASA/JPL |
| Date |
October 12, 2006 |
|
Huygens Landing Site Similar
…
| Description |
Huygens Landing Site Similarities |
| Full Description |
This area imaged by the Cassini radar system during the spacecraft's third close flyby of Titan on Feb. 15, 2005, is just to the east of the Circus Maximus impact feature (see http://photojournal.jpl.nasa.gov/catalog/PIA07365). The white lines could be channels in which fluid flowed from the slopes of Circus Maximus toward the bright area in the upper right. Areas that appear bright at radar wavelengths may be rough or inclined toward the direction of illumination. The bright area in this image could have received outflows of debris from the channels, making the surface appear radar bright. In this sense, the area may resemble somewhat the rubble strewn plains in the region where the Huygens probe landed. The fluid carrying the debris was most likely liquid methane, given the extremely cold ambient conditions at the surface of Titan. The longest channel in the feature is approximately 200 kilometers long (124 miles). The seams running across the image are an effect of the matching of the different radar beams to assemble the full image. 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 Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The radar instrument team is based at JPL, working with team members from the United States and several European countries. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. *Credit:* NASA/JPL |
| Date |
February 18, 2005 |
|
Lakes and More lakes
| Description |
Lakes and More lakes |
| Full Description |
In this image taken by the Cassini radar system, a previously unseen style of lakes is revealed. The lakes here assume complex shapes and are among the darkest seen so far on Titan. The lake at the left is reminiscent both in form and scale of the flooded drainage system, Lake Powell in Utah and Arizona. However, the Titan lake has been filled with liquid methane and ethane rather than water. In the lake at right, older terrain may have been deeply cut by river valleys before it was flooded by the embaying lake. For a different radar view from the same flyby see Titan's Great Lakes? . This radar image was acquired Oct. 9, 2006, and is centered near 80 degrees north latitude, 357 degrees west longitude. It measures about 310 kilometers by 100 kilometers (190 miles by 62 miles). Smallest details in this image are about 500 meters (1,640 feet) across. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The 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. Credit: NASA/JPL |
| Date |
October 12, 2006 |
|
Huygens Landing Site Similar
…
PIA07366
Saturn
Radar Mapper
| Title |
Huygens Landing Site Similarities |
| Original Caption Released with Image |
This area imaged by the Cassini radar system during the spacecraft's third close flyby of Titan on Feb. 15, 2005, is just to the east of the Circus Maximus impact feature (see PIA07365 [ http://photojournal.jpl.nasa.gov/catalog/PIA07365 ]). The white lines could be channels in which fluid flowed from the slopes of Circus Maximus toward the bright area in the upper right. Areas that appear bright at radar wavelengths may be rough or inclined toward the direction of illumination. The bright area in this image could have received outflows of debris from the channels, making the surface appear radar bright. In this sense, the area may resemble somewhat the rubble strewn plains in the region where the Huygens probe landed. The fluid carrying the debris was most likely liquid methane, given the extremely cold ambient conditions at the surface of Titan. The longest channel in the feature is approximately 200 kilometers long (124 miles). The seams running across the image are an effect of the matching of the different radar beams to assemble the full image. 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 Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The radar instrument team is based at JPL, working with team members from the United States and several European countries. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. |
|
Space radar image of Mississ
…
PIA01311
Sol (our sun)
Imaging Radar
| Title |
Space radar image of Mississippi River |
| Original Caption Released with Image |
This image of the Mississippi River in Mississippi, Arkansas, and Louisiana shows regions of the southern United States that are prone to flooding. Data acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture imaging radar system, which flew on two space shuttle missions in April and October 1994, can help scientists assess flooding potentials and improve land management for future agricultural development. This image was acquired on October 9, 1994, during orbit 151 of the space shuttle Endeavour. The image is centered at about 32.75 degrees north latitude and 90.5 degrees west longitude and covers an area of about 23 kilometers by 40 kilometers (14.2 miles by 24.8 miles). North is toward the upper right of the image. The different colors represent the data return in different radar channels: red is L-band, vertically transmitted and received, green is L-band vertically transmitted and horizontally received, and blue is C-band vertically transmitted and received. This site along the Mississippi River lies north of Vicksburg along the Arkansas-Louisiana-Mississippi state borders. The river marks the stateline. Louisiana and Arkansas lie above the river and Mississippi is below the river. This region is characterized by rich farmland where a variety of crops are grown. The town located in the extreme upper left hand corner is Eudora, Arkansas. The long, narrow lakes which lie roughly parallel to the river are called oxbow lakes, named for the U-shaped harness worn by an ox. Oxbows are formed when a river changes course, abandoning old channels in favor of a new course. As the river changes course, the surrounding land dries out, leaving these lakes isolated. Oxbow lakes are common in areas where rivers flow through generally flat terrain, allowing the river to easily change course. The green regions bordering the river are undeveloped forested areas |
|
Bam, Iran, Radar Interferome
…
PIA06311
Sol (our sun)
Advanced Synthetic Aperture
…
| Title |
Bam, Iran, Radar Interferometry -- Earthquake |
| Original Caption Released with Image |
A magnitude 6.5 earthquake devastated the small city of Bam in southeast Iran on December 26, 2003 at 5:26 AM local time. While there have been several recent earthquakes on faults in the region, the city of Bam had not been affected by earthquakes for at least 500 years. Initial field studies found some minor evidence of fault motion, but the main fault rupture that caused the earthquake was discovered by analysis of data from the recently launched Envisat synthetic aperture radar system. Scientists from NASA's JPL and the Centre for Observation and Modelling of Earthquakes and Tectonics (University of Oxford, UK and the University of Cambridge, UK) used interferometry analysis of the Envisat radar data and seismology to study the fault rupture, that passed directly beneath the center of the city of Bam. The interferometry analysis was performed with software developed at JPL. A less used type of radar interferometry analysis called the interferometric correlation (shown in this figure) was used to locate the surface trace of the fault rupture. Scientists from the Geological Survey of Iran mapped the surface ruptures in the field at the locations discovered on these correlation images. The two images show similar measures of the radar interferometric correlation in grayscale on the left and in false colors on the right. The city of Bam is at the top edge of the images, which are each 5 km (3 miles) wide. In the left image, the irregular black line between the two red arrows shows the fault rupture, where the interferometric correlation is very low. The "S" shaped dark line running across the image from top left to lower right is a railroad, and some other straight lines are roads that also have low correlation. The right image shows the correlation in colors with the darkest red-orange color indicating low correlation on the fault ruptures and other features. For more information, see the following paper, published recently in Geophysical Research Letters: Talebian, M., Fielding, E.J., Funning, G.J., et al. (2004), The 2003 Bam (Iran) earthquake: Rupture of a blind strike-slip fault, L11611, doi:10.1029/2004GL020058. The full paper is available (subscription required) at http://www.agu.org/pubs/crossref/2004/2004GL020058.shtml [ http://www.agu.org/pubs/crossref/2004/2004GL020058.shtml ] and for United States Government research a reprint is available at http://techreports.jpl.nasa.gov/2004/2004-cit.html [ http://techreports.jpl.nasa.gov/2004/2004-cit.html ], Radar data used in this research were acquired by the Envisat satellite operated by the European Space Agency, which kindly made this data available for research. Part of this research was performed at the Jet Propulsion Laboratory, California Institute of Technology under contract with NASA. Part of this research was performed at the Centre for the Observation and Modelling of Earthquakes and Tectonics supported by the U.K. Natural Environment Research Council. Research was also performed by the Geological Survey of Iran. Size: Images are 5 km (3 miles) wide Location: 29.1 degrees North latitude, 58.3 degrees East longitude Orientation: North is up (UTM projection) Image Data: Envisat ASAR interferometric correlation Image resolution: 20 meters (60 feet) Dates Acquired: December 3, 2003 and January 7, 2004 |
|
Titan's Great Lakes?
PIA01942
Saturn
Radar Mapper
| Title |
Titan's Great Lakes? |
| Original Caption Released with Image |
Using its radar system, the Cassini spacecraft has imaged new lakes on Titan. The large dark patch seen on this image, at high latitudes surrounding Titan's north pole, is most likely a hydrocarbon lake. Several dark channels can be seen, the longest one at the left meanders over almost 100 kilometers (62 miles), and appears to drain into the lake. Some dark channels are remarkably straight, suggesting possible faulting in the subsurface. The bright landforms jutting into the lake indicate that old, eroded landforms may have flooded. For a different radar view from the same flyby see PIA01943 [ http://photojournal.jpl.nasa.gov/catalog/PIA01943 ]. This radar image was acquired by the Cassini radar instrument in synthetic aperture mode on Oct. 9, 2006. The image is centered near 73 degrees north latitude, 343 degrees west longitude, and measures about 300 kilometers by 140 kilometers (190 miles by 90 miles). Smallest details in this image are about 500 meters (1,640 feet) across. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The radar instrument team is based at JPL, working with team members from the United States and several European countries. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm [ http://saturn.jpl.nasa.gov ]. |
|
Lakes and more lakes
PIA01943
Saturn
Radar Mapper
| Title |
Lakes and more lakes |
| Original Caption Released with Image |
In this image taken by the Cassini radar system, a previously unseen style of lakes is revealed. The lakes here assume complex shapes and are among the darkest seen so far on Titan. The lake at the left is reminiscent both in form and scale of the flooded drainage system, Lake Powell in Utah and Arizona. However, the Titan lake has been filled with liquid methane and ethane rather than water. In the lake at right, older terrain may have been deeply cut by river valleys before it was flooded by the embaying lake. For a different radar view from the same flyby see PIA01942 [ http://photojournal.jpl.nasa.gov/catalog/PIA01942 ]. This radar image was acquired Oct. 9, 2006, and is centered near 80 degrees north latitude, 357 degrees west longitude. It measures about 310 kilometers by 100 kilometers (190 miles by 62 miles). Smallest details in this image are about 500 meters (1,640 feet) across. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The radar instrument team is based at JPL, working with team members from the United States and several European countries. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm [ http://saturn.jpl.nasa.gov ]. |
|
Lakes on Titan
PIA08630
Saturn
Radar Mapper
| Title |
Lakes on Titan |
| Original Caption Released with Image |
The Cassini spacecraft, using its radar system, has discovered very strong evidence for hydrocarbon lakes on Titan. Dark patches, which resemble terrestrial lakes, seem to be sprinkled all over the high latitudes surrounding Titan's north pole. Scientists have speculated that liquid methane or ethane might form lakes on Titan, particularly near the somewhat colder polar regions. In the images, a variety of dark patches, some with channels leading in or out of them, appear. The channels have a shape that strongly implies they were carved by liquid. Some of the dark patches and connecting channels are completely black, that is, they reflect back essentially no radar signal, and hence must be extremely smooth. In some cases rims can be seen around the dark patches, suggesting deposits that might form as liquid evaporates. The abundant methane in Titan's atmosphere is stable as a liquid under Titan conditions, as is its abundant chemical product, ethane, but liquid water is not. For all these reasons, scientists interpret the dark areas as lakes of liquid methane or ethane, making Titan the only body in the solar system besides Earth known to possess lakes. Because such lakes may wax and wane over time, and winds may alter the roughness of their surfaces, repeat coverage of these areas should test whether these are indeed bodies of liquid. These two radar images were acquired by the Cassini radar instrument in synthetic aperture mode on July 21, 2006. The top image centered near 80 degrees north, 92 degrees west measures about 420 kilometers by 150 kilometers (260 miles by 93 miles). The lower image centered near 78 degrees north, 18 degrees west measures about 475 kilometers by 150 kilometers (295 miles by 93 miles). Smallest details in this image are about 500 meters (1,640 feet) across. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The 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 [ http://saturn.jpl.nasa.gov ]. |
|
|
