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Pale Blue Orb (1)
| Description |
Pale Blue Orb |
| Full Description |
Not since NASA's Voyager 1 spacecraft saw our home as a pale blue dot from beyond the orbit of Neptune has Earth been imaged in color from the outer solar system. Now, Cassini casts powerful eyes on our home planet, and captures Earth, a pale blue orb -- and a faint suggestion of our moon -- among the glories of the Saturn system. Earth is captured here in a natural color portrait made possible by the passing of Saturn directly in front of the sun from Cassini's point of view. At the distance of Saturn's orbit, Earth is too narrowly separated from the sun for the spacecraft to safely point its cameras and other instruments toward its birthplace without protection from the sun's glare. The Earth-and-moon system is visible as a bright blue point on the right side of the image above center. Here, Cassini is looking down on the Atlantic Ocean and the western coast of north Africa. The phase angle of Earth, seen from Cassini is about 30 degrees. A magnified view of the image taken through the clear filter (monochrome) shows the moon as a dim protrusion to the upper left of Earth. Seen from the outer solar system through Cassini's cameras, the entire expanse of direct human experience, so far, is nothing more than a few pixels across. Earth no longer holds the distinction of being our solar system's only "water world," as several other bodies suggest the possibility that they too harbor liquid water beneath their surfaces. The Saturnian moon, Enceladus, is among them, and is also captured on the left in this image (see inset), with its plume of water ice particles and swathed in the blue E ring which it creates. Delicate fingers of material extend from the active moon into the E ring. See Ghostly Fingers of Enceladus, for a more detailed view of these newly-revealed features. The narrow tenuous G ring and the main rings are seen at the right. The view looks down from about 15 degrees above the un-illuminated side of the rings. Images taken using red, green and blue spectral filters were combined to create this view. The image was taken by the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a sun-Saturn-spacecraft angle of almost 179 degrees. Image scale is 129 kilometers (80 miles) per pixel. At this time, Cassini was nearly 1.5 billion kilometers (930 million miles) from Earth. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov ., The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
September 19, 2006 |
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Shorefront Property, Anyone?
| Description |
Shorefront Property, Anyone? |
| Full Description |
This lake is part of a larger image taken by the Cassini radar instrument during a flyby of Saturn's moon Titan on Sept. 23, 2006. It shows clear shorelines that are reminiscent of terrestrial lakes. With Titan's colder temperatures and hydrocarbon-rich atmosphere, however, the lakes likely contain a combination of methane and ethane, not water. Centered near 74 degrees north, 65 degrees west longitude, this lake is roughly 20 kilometers by 25 kilometers (12 to 16 miles) across. It features several narrow or angular bays, including a broad peninsula that on Earth would be evidence that the surrounding terrain is higher and confines the liquid. Broader bays, such as the one seen at right, might result when the terrain is gentler, as for example on a beach. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . Credit: NASA/JPL |
| Date |
September 26, 2006 |
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In Saturn's Shadow (Color-ex
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| Description |
In Saturn's Shadow (Color-exagerated view) |
| Full Description |
+ Original version + Image with labels With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world. This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints, only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color. The mosaic images were acquired as the spacecraft drifted in the darkness of Saturn's shadow for about 12 hours, allowing a multitude of unique observations of the microscopic particles that compose Saturn's faint rings. Ring structures containing these tiny particles brighten substantially at high phase angles: i.e., viewing angles where the sun is almost directly behind the objects being imaged. During this period of observation Cassini detected two new faint rings: one coincident with the shared orbit of the moons Janus and Epimetheus, and another coincident with Pallene's orbit. (See The Janus/Epimetheus Ring and Moon-Made Rings for more on the two new rings.) The narrowly confined G ring is easily seen here, outside the bright main rings. Encircling the entire system is the much more extended E ring. The icy plumes of Enceladus, whose eruptions supply the E ring particles, betray the moon's position in the E ring's left-side edge. Interior to the G ring and above the brighter main rings is the pale dot of Earth. Cassini views its point of origin from over a billion kilometers (and close to a billion miles) away in the icy depths of the outer solar system. See Pale Blue Orb for a similar view of Earth taken during this observation. Small grains are pushed about by sunlight and electromagnetic forces. Hence their distribution tells much about the local space environment. A second version of the mosaic view is presented here in which the color contrast is greatly exaggerated. In such views, imaging scientists have noticed color variations across the diffuse rings that imply active processes sort the particles in the ring according to their sizes. Looking at the E ring in this color-exaggerated view, the distribution of color across and along the ring appears to be different between the right side and the left. Scientists are not sure yet how to explain these differences, though the difference in phase angle between right and left may be part of the explanation. The phase angle is about 179 degrees on Saturn. The main rings are overexposed in a few places. This view looks toward the unlit side of the rings from about 15 degrees above the ringplane. Cassini was approximately 2.2 million kilometers (1.3 million miles) from Saturn when the, images in this mosaic were taken. Image scale on Saturn is about 260 kilometers (162 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
October 11, 2006 |
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| Description |
Titan's |
| Full Description |
This Cassini radar image shows two lakes "kissing" each other on the surface of Saturn's moon Titan. The image from a flyby on Sept. 23, 2006, covers an area about 60 kilometers (37 miles) wide by 40 kilometers (25 miles) high. This pass was primarily dedicated to the ion and neutral mass spectrometer instrument, so although, the volume of radar data was small, scientists were amazed to see Earth-like lakes. With Titan's colder temperatures and hydrocarbon-rich atmosphere, however, the lakes likely contain a combination of methane and ethane, not water. In this image, near 73 degrees north latitude, 46 degrees west longitude, two lakes are seen, each 20 to 25 kilometers (12 to 16 miles) across. They are joined by a relatively narrow channel. The lake on the right has lighter patches within it, indicating that it may be slowly drying out as the northern summer approaches. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . Credit: NASA/JPL |
| Date |
September 26, 2006 |
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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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Moons in the Night
| Description |
Moons in the Night |
| Full Description |
Sunlight makes visible the faint band called the E ring as two moons meet in the sky. Enceladus (505 kilometers, or 314 miles across) and Tethys (1,071 kilometers, or 665 miles across) appear close together in the sky in this image, but in reality, Tethys was more than 260,000 kilometers (162,000 miles) farther from the Cassini spacecraft -- greater than half the distance from Earth to the Moon. Enceladus is easy to identify by the brilliant plume of ice erupting from its south pole. Although this perspective views the night sides of both moons, the Sun is not the only source of illumination in the Saturn system. Tethys is at a fuller phase with respect to Saturn, and thus its "night side" is more fully lit than that of Enceladus. The view was acquired from a Sun-Enceladus-spacecraft, or phase, angle of 163 degrees, a viewing geometry in which the microscopic ice particles in its plume brighten substantially. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 6, 2006 at a distance of approximately 3.9 million kilometers (2.4 million miles) from Enceladus and 4.2 million kilometers (2.6 million miles) from Tethys. Image scale is 23 kilometers (14 miles) per pixel on Enceladus and 25 kilometers (16 miles) on Tethys. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
April 16, 2007 |
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Radar Shows Evidence of Seas
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
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, This movie, comprised of several detailed images taken by Cassini's radar instrument, shows bodies of liquid near Titan's north pole. These images show that many of the features commonly associated with lakes on Earth, such as islands, bays, inlets and channels, are also present on this cold Saturnian moon. They offer strong evidence that larger bodies seen in infrared images are, in fact, seas. These seas are most likely liquid methane and ethane. For more than two decades, scientists have debated whether liquids on Titan exist, and if so, where they would be located. Pre-Cassini observations from the 1980s indicated that something on Titan's surface must be re-supplying the methane to its atmosphere. A global ocean was once hypothesized. Subsequently, disconnected lakes or seas were predicted. The discovery of numerous lakes near Titan's north pole by the Cassini radar instrument in July 2006 has confirmed the latter idea, and indicates an apparent preference during the current season for liquids to be located near the north pole. These new observations of the north polar area show how extensive and widespread these lakes are, and reveal at least one body of liquid that might rightly be called a sea. These seas cover an area about 100,000 square kilometers (about 39,000 square miles), larger than the largest Great Lake, Lake Superior, near the U.S. and Canadian border, whose area is 82,000 square kilometers (about 32,000 square miles). Analysis of the data indicates that the bodies of liquid may be tens of meters in depth. This high-definition video offers a trip through the north polar area just as Cassini radar saw it. It combines radar swaths seen on several Titan passes: July 22, 2006 (T16), Sept. 23, 2006 (T18), Oct. 9, 2006 (T19), and Feb. 22, 2007 (T25), respectively. The mosaic reveals the extent of the lakes, their shapes and interconnections. The areas believed to be composed of liquids are shown in blue as an aid to interpretation. The movie begins with an illustration of the relative orbits of Titan and Cassini, both circling Saturn. The spacecraft is seen approaching the planet with a nodding motion as its antenna scans the moon's surface, turning to keep its target in sight. The animation shows all radar swaths, and zooms in for a close look at the many complex shapes the lakes take. Some features that resemble lakes with no liquid may be remnants that have already dried as the northern winter fades into spring. The resolution of the radar data varies from several kilometers to as fine as 300 meters (984 feet). The coverage shown in the video spans from 50 degrees north latitude, almost to the pole, where a small triangular gap in coverage misses the exact pole. 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 |
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Radar Shows Evidence of Seas
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
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, This movie, comprised of several detailed images taken by Cassini's radar instrument, shows bodies of liquid near Titan's north pole. These images show that many of the features commonly associated with lakes on Earth, such as islands, bays, inlets and channels, are also present on this cold Saturnian moon. They offer strong evidence that larger bodies seen in infrared images are, in fact, seas. These seas are most likely liquid methane and ethane. For more than two decades, scientists have debated whether liquids on Titan exist, and if so, where they would be located. Pre-Cassini observations from the 1980s indicated that something on Titan's surface must be re-supplying the methane to its atmosphere. A global ocean was once hypothesized. Subsequently, disconnected lakes or seas were predicted. The discovery of numerous lakes near Titan's north pole by the Cassini radar instrument in July 2006 has confirmed the latter idea, and indicates an apparent preference during the current season for liquids to be located near the north pole. These new observations of the north polar area show how extensive and widespread these lakes are, and reveal at least one body of liquid that might rightly be called a sea. These seas cover an area about 100,000 square kilometers (about 39,000 square miles), larger than the largest Great Lake, Lake Superior, near the U.S. and Canadian border, whose area is 82,000 square kilometers (about 32,000 square miles). Analysis of the data indicates that the bodies of liquid may be tens of meters in depth. This high-definition video offers a trip through the north polar area just as Cassini radar saw it. It combines radar swaths seen on several Titan passes: July 22, 2006 (T16), Sept. 23, 2006 (T18), Oct. 9, 2006 (T19), and Feb. 22, 2007 (T25), respectively. The mosaic reveals the extent of the lakes, their shapes and interconnections. The areas believed to be composed of liquids are shown in blue as an aid to interpretation. The movie begins with an illustration of the relative orbits of Titan and Cassini, both circling Saturn. The spacecraft is seen approaching the planet with a nodding motion as its antenna scans the moon's surface, turning to keep its target in sight. The animation shows all radar swaths, and zooms in for a close look at the many complex shapes the lakes take. Some features that resemble lakes with no liquid may be remnants that have already dried as the northern winter fades into spring. The resolution of the radar data varies from several kilometers to as fine as 300 meters (984 feet). The coverage shown in the video spans from 50 degrees north latitude, almost to the pole, where a small triangular gap in coverage misses the exact pole. 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 |
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Mimas...and Titan Beyond
| Description |
Mimas...and Titan Beyond |
| Full Description |
Titan, Saturn's largest moon, and Mimas, closer but much smaller on the right, are seen together in this view from Cassini. Titan's gravity is weaker than Earth's, so the moon's atmosphere is quite extended -- a quality hinted at in this view. Part of Mimas' dark side is illuminated by reflected light from nearby Saturn. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 3, 2005, at a distance of approximately 3.6 million kilometers (2.2 million miles) from Titan (5,150 kilometers, or 3,200 miles across) and 2.5 million kilometers (1.6 million miles) from Mimas (397 kilometers, or 247 miles across). Both moons are seen at a Sun-moon-spacecraft angle, or phase angle, of 110 degrees. The image scale is 22 kilometers (14 miles) per pixel on Titan and 15 kilometers (9 miles) per pixel on Mimas. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
January 3, 2006 |
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The Storm Continues
| Description |
The Storm Continues |
| Full Description |
The Cassini spacecraft looks toward giant Saturn and its moon Tethys, while a large and powerful storm rages in the planet's southern hemisphere. The storm was observed by the Cassini spacecraft beginning in late Jan. 2006, and was at the time large and bright enough to be seen using modest-sized telescopes on Earth. The fact that the storm stands out against the subtle banding of Saturn at visible wavelengths suggests that the storm's cloud tops are relatively high in the atmosphere. Tethys is 1,071 kilometers (665 miles) across. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Feb. 18, 2006, at a distance of approximately 2.8 million kilometers (1.7 million miles) from Saturn. The image scale is 162 kilometers (101 miles) per pixel on Saturn. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
March 29, 2006 |
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From Cloudy to Clear
| Description |
During a recent flyby of Titan, the Cassini spacecraft looked beyond the utterly overcast moon and spied clear, distant Rhea in the blackness. |
| Full Description |
During a recent flyby of Titan, the Cassini spacecraft looked beyond the utterly overcast moon and spied clear, distant Rhea in the blackness. Titan (5,150 kilometers, or 3,200 miles across) is two-and-a-half times smaller than Earth and much less massive. This circumstance causes its atmosphere to extend to much higher altitudes above the surface than does Earth's. The Cassini spacecraft is unable to fly much closer than about 1000 kilometers (600 miles) above Titan's surface -- much closer, and the spacecraft would experience excessive torques from the atmosphere that could interfere with its ability to track the target. By contrast, the International Space Station orbits Earth at an altitude of about 350 kilometers (220 miles). The bright, fresh crater on Rhea (1,528 kilometers, or 949 miles across) appears near the center of the moon's crescent. The image was taken in visible-light with the Cassini spacecraft wide-angle camera on May 20, 2006, at a distance of approximately 53,000 kilometers (33,000 miles) from Titan and 873,000 kilometers (543,000 miles) from Rhea. Image scale is 320 meters (1,050 feet) per pixel on Titan and 5 kilometers (3 miles) per pixel on Rhea. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
June 21, 2006 |
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In Saturn's Shadow (with lab
…
| Description |
In Saturn's Shadow (with labels) |
| Full Description |
+ Original version + Color-exagerated version With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world. This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints, only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color. The mosaic images were acquired as the spacecraft drifted in the darkness of Saturn's shadow for about 12 hours, allowing a multitude of unique observations of the microscopic particles that compose Saturn's faint rings. Ring structures containing these tiny particles brighten substantially at high phase angles: i.e., viewing angles where the sun is almost directly behind the objects being imaged. During this period of observation Cassini detected two new faint rings: one coincident with the shared orbit of the moons Janus and Epimetheus, and another coincident with Pallene's orbit. (See The Janus/Epimetheus Ring and Moon-Made Rings for more on the two new rings.) The narrowly confined G ring is easily seen here, outside the bright main rings. Encircling the entire system is the much more extended E ring. The icy plumes of Enceladus, whose eruptions supply the E ring particles, betray the moon's position in the E ring's left-side edge. Interior to the G ring and above the brighter main rings is the pale dot of Earth. Cassini views its point of origin from over a billion kilometers (and close to a billion miles) away in the icy depths of the outer solar system. See Pale Blue Orb for a similar view of Earth taken during this observation. Small grains are pushed about by sunlight and electromagnetic forces. Hence their distribution tells much about the local space environment. A second version of the mosaic view is presented here in which the color contrast is greatly exaggerated. In such views, imaging scientists have noticed color variations across the diffuse rings that imply active processes sort the particles in the ring according to their sizes. Looking at the E ring in this color-exaggerated view, the distribution of color across and along the ring appears to be different between the right side and the left. Scientists are not sure yet how to explain these differences, though the difference in phase angle between right and left may be part of the explanation. The phase angle is about 179 degrees on Saturn. The main rings are overexposed in a few places. This view looks toward the unlit side of the rings from about 15 degrees above the ringplane. Cassini was approximately 2.2 million kilometers (1.3 million miles) from Saturn when, the images in this mosaic were taken. Image scale on Saturn is about 260 kilometers (162 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
October 11, 2006 |
|
Radar Images the Margin of X
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| Description |
Radar Images the Margin of Xanadu |
| Full Description |
This image of Saturn's moon Titan from the Synthetic Aperture Radar instrument on the Cassini spacecraft shows the southwestern area of a feature called Xanadu (bottom right of the image). The area is bright because it reflects the radio wavelengths used to make this radar images. The image was taken on April 30, 2006. Xanadu is one of the most prominent features on Titan and was first seen in ground-based observations. The origin of Xanadu is still unknown, but this radar image reveals details previously unseen, such as numerous curvy features that may indicate fluid flows. Linear dark streaks visible in radar-dark areas are dune fields, also seen in previous radar images (see Dunes Galore). Near the center of the image is a prominent circular feature, named Guabonito, about 90 kilometers (56 miles) in diameter. It might be an impact crater or a cryovolcanic caldera. If this is an impact structure, the absence of an ejecta blanket suggests that the feature has been highly eroded, like some impact structures on Earth, or has been buried by the dune fields. Other radar-bright areas (top left and top right) appear to be topographically high and might act as obstacles, diverting the dunes around them. 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 |
May 3, 2006 |
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Pale Blue Orb (2)
| title |
Pale Blue Orb (2) |
| date |
09.15.2006 |
| description |
Not since NASA's Voyager 1 spacecraft saw our home as a pale blue dot from beyond the orbit of Neptune has Earth been imaged in color from the outer solar system. Now, Cassini casts powerful eyes on our home planet, and captures Earth, a pale blue orb -- and a faint suggestion of our moon -- among the glories of the Saturn system. Earth is captured here in a natural color portrait made possible by the passing of Saturn directly in front of the sun from Cassini's point of view. At the distance of Saturn's orbit, Earth is too narrowly separated from the sun for the spacecraft to safely point its cameras and other instruments toward its birthplace without protection from the sun's glare. The Earth-and-moon system is visible as a bright blue point on the right side of the image above center. Here, Cassini is looking down on the Atlantic Ocean and the western coast of north Africa. The phase angle of Earth, seen from Cassini is about 30 degrees. A magnified view of the image taken through the clear filter (monochrome) shows the moon as a dim protrusion to the upper left of Earth. Seen from the outer solar system through Cassini's cameras, the entire expanse of direct human experience, so far, is nothing more than a few pixels across. Earth no longer holds the distinction of being our solar system's only "water world," as several other bodies suggest the possibility that they too harbor liquid water beneath their surfaces. The Saturnian moon, Enceladus, is among them, and is also captured on the left in this image, with its plume of water ice particles and swathed in the blue E ring which it creates. Delicate fingers of material extend from the active moon into the E ring. See Ghostly Fingers of Enceladus [ http://saturn.jpl.nasa.gov/multimedia/images/image-details.cfm?imageID=2276 ], for a more detailed view of these newly-revealed features. The narrow tenuous G ring and the main rings are seen at the right. The view looks down from about 15 degrees above the un-illuminated side of the rings. Images taken using red, green and blue spectral filters were combined to create this view. The image was taken by the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a sun-Saturn-spacecraft angle of almost 179 degrees. Image scale is approximately 250 kilometers (155 miles) per pixel. At this time, Cassini was nearly 1.5 billion kilometers (930 million miles) from Earth. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For, more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ] . The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ] . Credit: NASA/JPL/Space Science Institute |
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Hubble Captures a Rare Eclip
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| Title |
Hubble Captures a Rare Eclipse on Uranus |
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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 Sees Faintest Stars i
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| Title |
Hubble Sees Faintest Stars in a Globular Cluster |
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Full-Frame Reference for Tes
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| title |
Full-Frame Reference for Test Photo of Moon |
| Description |
This pair of views shows how little of the full image frame was taken up by the Moon in test images taken Sept. 8, 2005, by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The Mars-bound camera imaged Earth's Moon from a distance of about 10 million kilometers (6 million miles) away -- 26 times the distance between Earth and the Moon -- as part of an activity to test and calibrate the camera. The images are very significant because they show that the Mars Reconnaissance Orbiter spacecraft and this camera can properly operate together to collect very high-resolution images of Mars. The target must move through the camera's telescope view in just the right direction and speed to acquire a proper image. The day's test images also demonstrate that the focus mechanism works properly with the telescope to produce sharp images. Out of the 20,000-pixel-by-6,000-pixel full frame, the Moon's diameter is about 340 pixels, if the full Moon could be seen. The illuminated crescent is about 60 pixels wide, and the resolution is about 10 kilometers (6 miles) per pixel. At Mars, the entire image region will be filled with high-resolution information. The Mars Reconnaissance Orbiter, launched on Aug. 12, 2005, is on course to reach Mars on March 10, 2006. After gradually adjusting the shape of its orbit for half a year, it will begin its primary science phase in November 2006. From the mission's planned science orbit about 300 kilometers (186 miles) above the surface of Mars, the high resolution camera will be able to discern features as small as one meter or yard across. The Mars Reconnaissance Orbiter mission is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for the NASA Science Mission Directorate. Lockheed Martin Space Systems, Denver, prime contractor for the project, built the spacecraft. Ball Aerospace & Technologies Corp., Boulder, Colo., built the High Resolution Imaging Science Experiment instrument for the University of Arizona, Tucson, to provide to the mission. The HiRISE Operations Center at the University of Arizona processes images from the camera. Credit: NASA/JPL/University of Arizona |
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First HiRISE image of Mars
| title |
First HiRISE image of Mars |
| Description |
. 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 is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. Credit: NASA/JPL/University of Arizona, The first image of Mars by the High Resolution Imaging Science Experiment (HiRISE) on NASA's Mars Reconnaissance Orbiter shows a story of geologic change in the eastern Bosporos Planum region. Old stream valleys cut into the flanks of a gently sloping mountain range in the center of the image. Layers of smooth-textured deposits have mantled the stream valleys and many impact craters. Wind and sublimation of water or carbon dioxide ice have partially eroded patches of the smooth-textured deposits, leaving behind areas of layered and hummocky terrain. A prominent ridge that extends from the top to the bottom of the image dominates the scene. This ridge formed above a thrust fault, a type of fault that occurs when the surface of a planet is compressed. On planetary surfaces, such fault-related ridges are termed "wrinkle ridges." They are commonly observed on Mars, as well as on Earth's moon and on Venus and Mercury. The wrinkle ridge imaged here is named Ogygis Rupes. This wrinkle ridge has deformed several valleys and impact craters. Throughout the scene, geologically young sand dunes are present within stream valleys and some impact craters. The area is also sprinkled with many small young impact craters, which are distinguished by sharp crater rims and bright or dark halos of ejected material. This image demonstrates how a single HiRISE image can capture a multitude of geologic processes. Image AEB_000001_0000_Red was taken by HiRISE on March 24, 2006. The image is centered at 33.65 degrees south latitude, 305.07 degrees east longitude. It is oriented such that north is 7 degrees to the left of up. The range to the target was 2,493 kilometers (1,549 miles). At this distance the image scale is 2.49 meters (8.17 feet) per pixel, so objects as small as 7.5 meters (24.6 feet) are resolved. In total this image is 49.92 kilometers (31.02 miles) or 20,081 pixels wide and 23.66 kilometers (14.70 miles) or 9,523 pixels long. The image was taken at a local Mars time of 07:33 and the scene is illuminated from the upper right with a solar incidence angle of 78 degrees, thus the sun was 12 degrees above the horizon. At an Ls of 29 degrees (with Ls an indicator of Mars' position in its orbit around the sun), the season on Mars is southern autumn. Images from the High Resolution Imaging Science Experiment and additional information about the Mars Reconnaissance Orbiter are available online at: http://www.nasa.gov/mro [ http://www.nasa.gov/mro ] or http://HiRISE.lpl.arizona.edu [ http://HiRISE.lpl.arizona.edu ]. For information about NASA and agency programs on the Web, visit: http://www.nasa.gov [ http://www.nasa.gov ] |
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Radar Images the Margin of X
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PIA08425
Saturn
Radar Mapper
| Title |
Radar Images the Margin of Xanadu |
| Original Caption Released with Image |
This image of Saturn's moon Titan from the Synthetic Aperture Radar instrument on the Cassini spacecraft shows the southwestern area of a feature called Xanadu (bottom right of the image). The area is bright because it reflects the radio wavelengths used to make this radar images. The image was taken on April 30, 2006. Xanadu is one of the most prominent features on Titan and was first seen in ground-based observations. The origin of Xanadu is still unknown, but this radar image reveals details previously unseen, such as numerous curvy features that may indicate fluid flows. Linear dark streaks visible in radar-dark areas are dune fields, also seen in previous radar images (see PIA03567 [ http://photojournal.jpl.nasa.gov/catalog/PIA03567 ]). Near the center of the image is a prominent circular feature, named Guabonito, about 90 kilometers (56 miles) in diameter. It might be an impact crater or a cryovolcanic caldera. If this is an impact structure, the absence of an ejecta blanket suggests that the feature has been highly eroded, like some impact structures on Earth, or has been buried by the dune fields. Other radar-bright areas (top left and top right) appear to be topographically high and might act as obstacles, diverting the dunes around them. 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 ]. |
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Titan (T25) Viewed by Cassin
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PIA09182
Saturn
Radar Mapper
| Title |
Titan (T25) Viewed by Cassini's Radar - Feb. 22, 2007 |
| Original Caption Released with Image |
). 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 [ http://saturn.jpl.nasa.gov ]., 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 PIA08630 [ http://photojournal.jpl.nasa.gov/catalog/PIA08630 ]), 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 PIA09181 [ http://photojournal.jpl.nasa.gov/catalog/PIA09181 ]). 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 PIA01942 [ http://photojournal.jpl.nasa.gov/catalog/PIA01942 ]), 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 PIA01943 [ http://photojournal.jpl.nasa.gov/catalog/PIA01943 ]), 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 PIA09180 [ http://photojournal.jpl.nasa.gov/catalog/PIA09180 ] |
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Moons in the Night
PIA08919
Saturn
Imaging Science Subsystem -
…
| Title |
Moons in the Night |
| Original Caption Released with Image |
Sunlight makes visible the faint band called the E ring as two moons meet in the sky. Enceladus (505 kilometers, or 314 miles across) and Tethys (1,071 kilometers, or 665 miles across) appear close together in the sky in this image, but in reality, Tethys was more than 260,000 kilometers (162,000 miles) farther from the Cassini spacecraft -- greater than half the distance from Earth to the Moon. Enceladus is easy to identify by the brilliant plume of ice erupting from its south pole. Although this perspective views the night sides of both moons, the Sun is not the only source of illumination in the Saturn system. Tethys is at a fuller phase with respect to Saturn, and thus its "night side" is more fully lit than that of Enceladus. The view was acquired from a Sun-Enceladus-spacecraft, or phase, angle of 163 degrees, a viewing geometry in which the microscopic ice particles in its plume brighten substantially. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 6, 2006 at a distance of approximately 3.9 million kilometers (2.4 million miles) from Enceladus and 4.2 million kilometers (2.6 million miles) from Tethys. Image scale is 23 kilometers (14 miles) per pixel on Enceladus and 25 kilometers (16 miles) on Tethys. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm [ http://saturn.jpl.nasa.gov ]. The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ]. |
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From Cloudy to Clear
PIA08204
Saturn
Imaging Science Subsystem -
…
| Title |
From Cloudy to Clear |
| Original Caption Released with Image |
During a recent flyby of Titan, the Cassini spacecraft looked beyond the utterly overcast moon and spied clear, distant Rhea in the blackness. Titan (5,150 kilometers, or 3,200 miles across) is two-and-a-half times smaller than Earth and much less massive. This circumstance causes its atmosphere to extend to much higher altitudes above the surface than does Earth's. The Cassini spacecraft is unable to fly much closer than about 1000 kilometers (600 miles) above Titan's surface -- much closer, and the spacecraft would experience excessive torques from the atmosphere that could interfere with its ability to track the target. By contrast, the International Space Station orbits Earth at an altitude of about 350 kilometers (220 miles). The bright, fresh crater on Rhea (1,528 kilometers, or 949 miles across) appears near the center of the moon's crescent. The image was taken in visible-light with the Cassini spacecraft wide-angle camera on May 20, 2006, at a distance of approximately 53,000 kilometers (33,000 miles) from Titan and 873,000 kilometers (543,000 miles) from Rhea. Image scale is 320 meters (1,050 feet) per pixel on Titan and 5 kilometers (3 miles) per pixel on Rhea. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm [ http://saturn.jpl.nasa.gov ]. The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ]. |
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First HiRISE Image of Mars
PIA08060
Sol (our sun)
HiRISE
| Title |
First HiRISE Image of Mars |
| Original Caption Released with Image |
. JPL, 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 is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona., The first image of Mars by the High Resolution Imaging Science Experiment (HiRISE) on NASA's Mars Reconnaissance Orbiter shows a story of geologic change in the eastern Bosporos Planum region. Old stream valleys cut into the flanks of a gently sloping mountain range in the center of the image. Layers of smooth-textured deposits have mantled the stream valleys and many impact craters. Wind and sublimation of water or carbon dioxide ice have partially eroded patches of the smooth-textured deposits, leaving behind areas of layered and hummocky terrain. A prominent ridge that extends from the top to the bottom of the image dominates the scene. This ridge formed above a thrust fault, a type of fault that occurs when the surface of a planet is compressed. On planetary surfaces, such fault-related ridges are termed "wrinkle ridges." They are commonly observed on Mars, as well as on Earth's moon and on Venus and Mercury. The wrinkle ridge imaged here is named Ogygis Rupes. This wrinkle ridge has deformed several valleys and impact craters. Throughout the scene, geologically young sand dunes are present within stream valleys and some impact craters. The area is also sprinkled with many small young impact craters, which are distinguished by sharp crater rims and bright or dark halos of ejected material. This image demonstrates how a single HiRISE image can capture a multitude of geologic processes. This view results from further processing of an image released quickly after the data was received from the camera. See PIA08014 [ http://photojournal.jpl.nasa.gov/catalog/PIA08014 ]. It was taken by HiRISE on March 24, 2006. The image is centered at 33.65 degrees south latitude, 305.07 degrees east longitude. It is oriented such that north is 7 degrees to the left of up. The range to the target was 2,493 kilometers (1,549 miles). At this distance the image scale is 2.49 meters (8.17 feet) per pixel, so objects as small as 7.5 meters (24.6 feet) are resolved. In total this image is 49.92 kilometers (31.02 miles) or 20,081 pixels wide and 23.66 kilometers (14.70 miles) or 9,523 pixels long. The image was taken at a local Mars time of 07:33 and the scene is illuminated from the upper right with a solar incidence angle of 78 degrees, thus the sun was 12 degrees above the horizon. At an Ls of 29 degrees (with Ls an indicator of Mars' position in its orbit around the sun), the season on Mars is southern autumn. Images from the High Resolution Imaging Science Experiment and additional information about the Mars Reconnaissance Orbiter are available online at: http://www.nasa.gov/mro [ http://www.nasa.gov/mro ] or http://HiRISE.lpl.arizona.edu [ http://HiRISE.lpl.arizona.edu ]. For information about NASA and agency programs on the Web, visit: http://www.nasa.gov [ http://www.nasa.gov ] |
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Radar Shows Evidence of Seas
PIA09183
Saturn
Radar Mapper
| Title |
Radar Shows Evidence of Seas |
| Original Caption Released with Image |
"" Click on the image for full resolution movie Radar Shows Evidence of Seas (""Half Resolution, ) This movie, comprised of several detailed images taken by Cassini's radar instrument, shows bodies of liquid near Titan's north pole. These images show that many of the features commonly associated with lakes on Earth, such as islands, bays, inlets and channels, are also present on this cold Saturnian moon. They offer strong evidence that larger bodies seen in infrared images are, in fact, seas. These seas are most likely liquid methane and ethane. For more than two decades, scientists have debated whether liquids on Titan exist, and if so, where they would be located. Pre-Cassini observations from the 1980s indicated that something on Titan's surface must be re-supplying the methane to its atmosphere. A global ocean was once hypothesized. Subsequently, disconnected lakes or seas were predicted. The discovery of numerous lakes near Titan's north pole by the Cassini radar instrument in July 2006 has confirmed the latter idea, and indicates an apparent preference during the current season for liquids to be located near the north pole. These new observations of the north polar area show how extensive and widespread these lakes are, and reveal at least one body of liquid that might rightly be called a sea. These seas cover an area about 100,000 square kilometers (about 39,000 square miles), larger than the largest Great Lake, Lake Superior, near the U.S. and Canadian border, whose area is 82,000 square kilometers (about 32,000 square miles). Analysis of the data indicates that the bodies of liquid may be tens of meters in depth. This high-definition video offers a trip through the north polar area just as Cassini radar saw it. It combines radar swaths seen on several Titan passes: July 22, 2006 (T16), Sept. 23, 2006 (T18), Oct. 9, 2006 (T19), and Feb. 22, 2007 (T25), respectively. The mosaic reveals the extent of the lakes, their shapes and interconnections. The areas believed to be composed of liquids are shown in blue as an aid to interpretation. The movie begins with an illustration of the relative orbits of Titan and Cassini, both circling Saturn. The spacecraft is seen approaching the planet with a nodding motion as its antenna scans the moon's surface, turning to keep its target in sight. The animation shows all radar swaths, and zooms in for a close look at the many complex shapes the lakes take. Some features that resemble lakes with no liquid may be remnants that have already dried as the northern winter fades into spring. The resolution of the radar data varies from several kilometers to as fine as 300 meters (984 feet). The coverage shown in the video spans from 50 degrees north latitude, almost to the pole, where a small triangular gap in coverage misses the exact pole. 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 ]. |
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Radar Shows Evidence of Seas
PIA09183
Saturn
Radar Mapper
| Title |
Radar Shows Evidence of Seas |
| Original Caption Released with Image |
"" Click on the image for full resolution movie Radar Shows Evidence of Seas (""Half Resolution, ) This movie, comprised of several detailed images taken by Cassini's radar instrument, shows bodies of liquid near Titan's north pole. These images show that many of the features commonly associated with lakes on Earth, such as islands, bays, inlets and channels, are also present on this cold Saturnian moon. They offer strong evidence that larger bodies seen in infrared images are, in fact, seas. These seas are most likely liquid methane and ethane. For more than two decades, scientists have debated whether liquids on Titan exist, and if so, where they would be located. Pre-Cassini observations from the 1980s indicated that something on Titan's surface must be re-supplying the methane to its atmosphere. A global ocean was once hypothesized. Subsequently, disconnected lakes or seas were predicted. The discovery of numerous lakes near Titan's north pole by the Cassini radar instrument in July 2006 has confirmed the latter idea, and indicates an apparent preference during the current season for liquids to be located near the north pole. These new observations of the north polar area show how extensive and widespread these lakes are, and reveal at least one body of liquid that might rightly be called a sea. These seas cover an area about 100,000 square kilometers (about 39,000 square miles), larger than the largest Great Lake, Lake Superior, near the U.S. and Canadian border, whose area is 82,000 square kilometers (about 32,000 square miles). Analysis of the data indicates that the bodies of liquid may be tens of meters in depth. This high-definition video offers a trip through the north polar area just as Cassini radar saw it. It combines radar swaths seen on several Titan passes: July 22, 2006 (T16), Sept. 23, 2006 (T18), Oct. 9, 2006 (T19), and Feb. 22, 2007 (T25), respectively. The mosaic reveals the extent of the lakes, their shapes and interconnections. The areas believed to be composed of liquids are shown in blue as an aid to interpretation. The movie begins with an illustration of the relative orbits of Titan and Cassini, both circling Saturn. The spacecraft is seen approaching the planet with a nodding motion as its antenna scans the moon's surface, turning to keep its target in sight. The animation shows all radar swaths, and zooms in for a close look at the many complex shapes the lakes take. Some features that resemble lakes with no liquid may be remnants that have already dried as the northern winter fades into spring. The resolution of the radar data varies from several kilometers to as fine as 300 meters (984 feet). The coverage shown in the video spans from 50 degrees north latitude, almost to the pole, where a small triangular gap in coverage misses the exact pole. 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 ]. |
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Groundwater May be Source fo
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PIA09031
Sol (our sun)
Mars Orbiter Camera
| Title |
Groundwater May be Source for Erosion in Martian Gullies |
| Original Caption Released with Image |
Since their discovery early during the Mars Global Surveyor's Mars Orbiter Camera investigation, as first reported in June 2000, Martian gullies have presented a puzzle for the Mars science community: what fluid was responsible for the erosion that created the channels, and where did it come from? The gullies seem to be quite young in a geologic sense (millions of years or less), yet modern and geologically-recent Mars is an extremely dry place, where water ice sublimates directly to gas when the temperature is warm enough. Since June 2000, many hypotheses have been discussed at scientific meetings, in the scientific journals and elsewhere. The original June 2000 hypothesis held that the fluid was liquid water (either pure, salty, acidic, etc.) that came to the surface where slopes intersected conduits of groundwater. Such slopes include crater walls, valley walls, hills, massifs and crater central peaks. Later investigators explored the possibility that rather than liquid groundwater, the source was ground ice, which, under some climate conditions, melted to produce liquid runoff. Still others noted that thick mantles covered a fraction of the gully-bearing slopes, suggesting that the mantles were ancient, dust-covered snow or ice packs that might melt at the base to make liquid water runoff. Water was not the only fluid considered by various colleagues, carbon dioxide can be fluid at some pressures and temperatures. Fluid carbon dioxide was also proposed as a candidate fluidizing agent. Even dry mass movement, or land sliding, of unconsolidated granular material can exhibit some fluid-like behavior. Such mass movements were considered as an explanation for the gullies. The presence of channels primarily formed by erosion but also displaying features representing along-channel deposition, such as levees and meanders, and terminal depositional aprons consisting of dozens to hundreds of individual flow lobes, contributed to the general acceptance of the hypothesis that gullies involved the action of liquid water. Throughout the Mars Global Surveyor mission, the Mars Orbiter Camera team continued to image gullies at every opportunity, looking for new gullies, taking higher resolution images of previously identified gullies, and monitoring the gullies for changes that might occur. Among the results of this extensive survey are numerous examples of gullies that have geological relations to other things in their vicinity. This provides support for the hypothesis that the fluid responsible for the gullies came from beneath the ground, either as groundwater or melting of ice in the Martian subsurface. Three of the best examples are presented here. Figure A: The first picture shows a pair of gully channels that emerge, fully-born at nearly their full width, from beneath small overhangs on the north wall of Dao Vallis. These overhangs are probably created by the presence of a hard-rock layer. Liquid, probably water, percolated through permeable, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., layers just beneath these harder, more resistant rock layers. The arrow points to the place where one of the two neighboring channels emerges. This is a sub-frame of an image acquired on Jan. 10, 2006, located near 34.2 degrees south latitude, 268.1 degrees west longitude. The 150-meter scale bar is about 164 yards wide. Figure B: The second picture shows a gully that formed on the wall of a crater that intersected a mare-type ridge. The term, mare, is from the dark volcanic plains of Earth's moon, for example Mare Tranquilitatis was the plain on which the Apollo 11 crew landed in 1969. The lunar maria (maria is the plural form of mare), when viewed from above, have many "wrinkle" ridges. These ridges are the surface expression of thrust faults. The mare-type ridge in the picture shown here is thus the product of faulting, as rocks on the west (left) side of the image were thrust toward the east (right). Finding a gully associated with a fault is excellent evidence for the groundwater hypothesis, because ground water percolates through cracks and pores in the ground. On Earth, springs (where groundwater comes to the surface) are often found along fault lines. What is most important about this particular Martian gully is that it occurs equatorward of 30 degrees south, which is extremely unusual. The only gully in this crater is the one associated with the fault. It is essentially the site of a spring, now dried up perhaps. This picture is a sub-frame of an image located near 29.1 degrees south latitude, 207.5 degrees west longitude, acquired on Jan. 17, 2005. Figure C: The third picture shows a small crater on the rim of a larger crater. Only a small portion of the wall of this larger crater is captured in the image. Immediately beneath the small crater occurs a group of gullies. The presence of these gullies also supports the groundwater hypothesis because impacting meteors will fracture the rocks into which they form a crater. In this case, there would be an initial set of subsurface fractures caused by the large impact that created the original, large crater. Then, when the smaller crater formed, it would have created additional fractures in its vicinity. These extra fractures would then have provided pathways, or conduits, through which ground water would come to the surface on the wall of the larger crater, thus creating the gullies observed. One might speculate that the group of gullies was formed by the impact that made the small crater, because of the heat and fracturing of rock during the impact process. However, the gullies are much younger than the small crater, the ejecta from the small crater has been largely eroded away or buried, and the crater partially filled, while the gullies appear sharp, crisp and fresh. This is a portion of an image located near 33.9 degrees south latitude, 160 degrees west longitude, acquired on March 31, 2006. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, |
|
Groundwater May be Source fo
…
PIA09031
Sol (our sun)
Mars Orbiter Camera
| Title |
Groundwater May be Source for Erosion in Martian Gullies |
| Original Caption Released with Image |
Since their discovery early during the Mars Global Surveyor's Mars Orbiter Camera investigation, as first reported in June 2000, Martian gullies have presented a puzzle for the Mars science community: what fluid was responsible for the erosion that created the channels, and where did it come from? The gullies seem to be quite young in a geologic sense (millions of years or less), yet modern and geologically-recent Mars is an extremely dry place, where water ice sublimates directly to gas when the temperature is warm enough. Since June 2000, many hypotheses have been discussed at scientific meetings, in the scientific journals and elsewhere. The original June 2000 hypothesis held that the fluid was liquid water (either pure, salty, acidic, etc.) that came to the surface where slopes intersected conduits of groundwater. Such slopes include crater walls, valley walls, hills, massifs and crater central peaks. Later investigators explored the possibility that rather than liquid groundwater, the source was ground ice, which, under some climate conditions, melted to produce liquid runoff. Still others noted that thick mantles covered a fraction of the gully-bearing slopes, suggesting that the mantles were ancient, dust-covered snow or ice packs that might melt at the base to make liquid water runoff. Water was not the only fluid considered by various colleagues, carbon dioxide can be fluid at some pressures and temperatures. Fluid carbon dioxide was also proposed as a candidate fluidizing agent. Even dry mass movement, or land sliding, of unconsolidated granular material can exhibit some fluid-like behavior. Such mass movements were considered as an explanation for the gullies. The presence of channels primarily formed by erosion but also displaying features representing along-channel deposition, such as levees and meanders, and terminal depositional aprons consisting of dozens to hundreds of individual flow lobes, contributed to the general acceptance of the hypothesis that gullies involved the action of liquid water. Throughout the Mars Global Surveyor mission, the Mars Orbiter Camera team continued to image gullies at every opportunity, looking for new gullies, taking higher resolution images of previously identified gullies, and monitoring the gullies for changes that might occur. Among the results of this extensive survey are numerous examples of gullies that have geological relations to other things in their vicinity. This provides support for the hypothesis that the fluid responsible for the gullies came from beneath the ground, either as groundwater or melting of ice in the Martian subsurface. Three of the best examples are presented here. Figure A: The first picture shows a pair of gully channels that emerge, fully-born at nearly their full width, from beneath small overhangs on the north wall of Dao Vallis. These overhangs are probably created by the presence of a hard-rock layer. Liquid, probably water, percolated through permeable, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., layers just beneath these harder, more resistant rock layers. The arrow points to the place where one of the two neighboring channels emerges. This is a sub-frame of an image acquired on Jan. 10, 2006, located near 34.2 degrees south latitude, 268.1 degrees west longitude. The 150-meter scale bar is about 164 yards wide. Figure B: The second picture shows a gully that formed on the wall of a crater that intersected a mare-type ridge. The term, mare, is from the dark volcanic plains of Earth's moon, for example Mare Tranquilitatis was the plain on which the Apollo 11 crew landed in 1969. The lunar maria (maria is the plural form of mare), when viewed from above, have many "wrinkle" ridges. These ridges are the surface expression of thrust faults. The mare-type ridge in the picture shown here is thus the product of faulting, as rocks on the west (left) side of the image were thrust toward the east (right). Finding a gully associated with a fault is excellent evidence for the groundwater hypothesis, because ground water percolates through cracks and pores in the ground. On Earth, springs (where groundwater comes to the surface) are often found along fault lines. What is most important about this particular Martian gully is that it occurs equatorward of 30 degrees south, which is extremely unusual. The only gully in this crater is the one associated with the fault. It is essentially the site of a spring, now dried up perhaps. This picture is a sub-frame of an image located near 29.1 degrees south latitude, 207.5 degrees west longitude, acquired on Jan. 17, 2005. Figure C: The third picture shows a small crater on the rim of a larger crater. Only a small portion of the wall of this larger crater is captured in the image. Immediately beneath the small crater occurs a group of gullies. The presence of these gullies also supports the groundwater hypothesis because impacting meteors will fracture the rocks into which they form a crater. In this case, there would be an initial set of subsurface fractures caused by the large impact that created the original, large crater. Then, when the smaller crater formed, it would have created additional fractures in its vicinity. These extra fractures would then have provided pathways, or conduits, through which ground water would come to the surface on the wall of the larger crater, thus creating the gullies observed. One might speculate that the group of gullies was formed by the impact that made the small crater, because of the heat and fracturing of rock during the impact process. However, the gullies are much younger than the small crater, the ejecta from the small crater has been largely eroded away or buried, and the crater partially filled, while the gullies appear sharp, crisp and fresh. This is a portion of an image located near 33.9 degrees south latitude, 160 degrees west longitude, acquired on March 31, 2006. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, |
|
Groundwater May be Source fo
…
PIA09031
Sol (our sun)
Mars Orbiter Camera
| Title |
Groundwater May be Source for Erosion in Martian Gullies |
| Original Caption Released with Image |
Since their discovery early during the Mars Global Surveyor's Mars Orbiter Camera investigation, as first reported in June 2000, Martian gullies have presented a puzzle for the Mars science community: what fluid was responsible for the erosion that created the channels, and where did it come from? The gullies seem to be quite young in a geologic sense (millions of years or less), yet modern and geologically-recent Mars is an extremely dry place, where water ice sublimates directly to gas when the temperature is warm enough. Since June 2000, many hypotheses have been discussed at scientific meetings, in the scientific journals and elsewhere. The original June 2000 hypothesis held that the fluid was liquid water (either pure, salty, acidic, etc.) that came to the surface where slopes intersected conduits of groundwater. Such slopes include crater walls, valley walls, hills, massifs and crater central peaks. Later investigators explored the possibility that rather than liquid groundwater, the source was ground ice, which, under some climate conditions, melted to produce liquid runoff. Still others noted that thick mantles covered a fraction of the gully-bearing slopes, suggesting that the mantles were ancient, dust-covered snow or ice packs that might melt at the base to make liquid water runoff. Water was not the only fluid considered by various colleagues, carbon dioxide can be fluid at some pressures and temperatures. Fluid carbon dioxide was also proposed as a candidate fluidizing agent. Even dry mass movement, or land sliding, of unconsolidated granular material can exhibit some fluid-like behavior. Such mass movements were considered as an explanation for the gullies. The presence of channels primarily formed by erosion but also displaying features representing along-channel deposition, such as levees and meanders, and terminal depositional aprons consisting of dozens to hundreds of individual flow lobes, contributed to the general acceptance of the hypothesis that gullies involved the action of liquid water. Throughout the Mars Global Surveyor mission, the Mars Orbiter Camera team continued to image gullies at every opportunity, looking for new gullies, taking higher resolution images of previously identified gullies, and monitoring the gullies for changes that might occur. Among the results of this extensive survey are numerous examples of gullies that have geological relations to other things in their vicinity. This provides support for the hypothesis that the fluid responsible for the gullies came from beneath the ground, either as groundwater or melting of ice in the Martian subsurface. Three of the best examples are presented here. Figure A: The first picture shows a pair of gully channels that emerge, fully-born at nearly their full width, from beneath small overhangs on the north wall of Dao Vallis. These overhangs are probably created by the presence of a hard-rock layer. Liquid, probably water, percolated through permeable, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., layers just beneath these harder, more resistant rock layers. The arrow points to the place where one of the two neighboring channels emerges. This is a sub-frame of an image acquired on Jan. 10, 2006, located near 34.2 degrees south latitude, 268.1 degrees west longitude. The 150-meter scale bar is about 164 yards wide. Figure B: The second picture shows a gully that formed on the wall of a crater that intersected a mare-type ridge. The term, mare, is from the dark volcanic plains of Earth's moon, for example Mare Tranquilitatis was the plain on which the Apollo 11 crew landed in 1969. The lunar maria (maria is the plural form of mare), when viewed from above, have many "wrinkle" ridges. These ridges are the surface expression of thrust faults. The mare-type ridge in the picture shown here is thus the product of faulting, as rocks on the west (left) side of the image were thrust toward the east (right). Finding a gully associated with a fault is excellent evidence for the groundwater hypothesis, because ground water percolates through cracks and pores in the ground. On Earth, springs (where groundwater comes to the surface) are often found along fault lines. What is most important about this particular Martian gully is that it occurs equatorward of 30 degrees south, which is extremely unusual. The only gully in this crater is the one associated with the fault. It is essentially the site of a spring, now dried up perhaps. This picture is a sub-frame of an image located near 29.1 degrees south latitude, 207.5 degrees west longitude, acquired on Jan. 17, 2005. Figure C: The third picture shows a small crater on the rim of a larger crater. Only a small portion of the wall of this larger crater is captured in the image. Immediately beneath the small crater occurs a group of gullies. The presence of these gullies also supports the groundwater hypothesis because impacting meteors will fracture the rocks into which they form a crater. In this case, there would be an initial set of subsurface fractures caused by the large impact that created the original, large crater. Then, when the smaller crater formed, it would have created additional fractures in its vicinity. These extra fractures would then have provided pathways, or conduits, through which ground water would come to the surface on the wall of the larger crater, thus creating the gullies observed. One might speculate that the group of gullies was formed by the impact that made the small crater, because of the heat and fracturing of rock during the impact process. However, the gullies are much younger than the small crater, the ejecta from the small crater has been largely eroded away or buried, and the crater partially filled, while the gullies appear sharp, crisp and fresh. This is a portion of an image located near 33.9 degrees south latitude, 160 degrees west longitude, acquired on March 31, 2006. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, |
|
Groundwater May be Source fo
…
PIA09031
Sol (our sun)
Mars Orbiter Camera
| Title |
Groundwater May be Source for Erosion in Martian Gullies |
| Original Caption Released with Image |
Since their discovery early during the Mars Global Surveyor's Mars Orbiter Camera investigation, as first reported in June 2000, Martian gullies have presented a puzzle for the Mars science community: what fluid was responsible for the erosion that created the channels, and where did it come from? The gullies seem to be quite young in a geologic sense (millions of years or less), yet modern and geologically-recent Mars is an extremely dry place, where water ice sublimates directly to gas when the temperature is warm enough. Since June 2000, many hypotheses have been discussed at scientific meetings, in the scientific journals and elsewhere. The original June 2000 hypothesis held that the fluid was liquid water (either pure, salty, acidic, etc.) that came to the surface where slopes intersected conduits of groundwater. Such slopes include crater walls, valley walls, hills, massifs and crater central peaks. Later investigators explored the possibility that rather than liquid groundwater, the source was ground ice, which, under some climate conditions, melted to produce liquid runoff. Still others noted that thick mantles covered a fraction of the gully-bearing slopes, suggesting that the mantles were ancient, dust-covered snow or ice packs that might melt at the base to make liquid water runoff. Water was not the only fluid considered by various colleagues, carbon dioxide can be fluid at some pressures and temperatures. Fluid carbon dioxide was also proposed as a candidate fluidizing agent. Even dry mass movement, or land sliding, of unconsolidated granular material can exhibit some fluid-like behavior. Such mass movements were considered as an explanation for the gullies. The presence of channels primarily formed by erosion but also displaying features representing along-channel deposition, such as levees and meanders, and terminal depositional aprons consisting of dozens to hundreds of individual flow lobes, contributed to the general acceptance of the hypothesis that gullies involved the action of liquid water. Throughout the Mars Global Surveyor mission, the Mars Orbiter Camera team continued to image gullies at every opportunity, looking for new gullies, taking higher resolution images of previously identified gullies, and monitoring the gullies for changes that might occur. Among the results of this extensive survey are numerous examples of gullies that have geological relations to other things in their vicinity. This provides support for the hypothesis that the fluid responsible for the gullies came from beneath the ground, either as groundwater or melting of ice in the Martian subsurface. Three of the best examples are presented here. Figure A: The first picture shows a pair of gully channels that emerge, fully-born at nearly their full width, from beneath small overhangs on the north wall of Dao Vallis. These overhangs are probably created by the presence of a hard-rock layer. Liquid, probably water, percolated through permeable, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., layers just beneath these harder, more resistant rock layers. The arrow points to the place where one of the two neighboring channels emerges. This is a sub-frame of an image acquired on Jan. 10, 2006, located near 34.2 degrees south latitude, 268.1 degrees west longitude. The 150-meter scale bar is about 164 yards wide. Figure B: The second picture shows a gully that formed on the wall of a crater that intersected a mare-type ridge. The term, mare, is from the dark volcanic plains of Earth's moon, for example Mare Tranquilitatis was the plain on which the Apollo 11 crew landed in 1969. The lunar maria (maria is the plural form of mare), when viewed from above, have many "wrinkle" ridges. These ridges are the surface expression of thrust faults. The mare-type ridge in the picture shown here is thus the product of faulting, as rocks on the west (left) side of the image were thrust toward the east (right). Finding a gully associated with a fault is excellent evidence for the groundwater hypothesis, because ground water percolates through cracks and pores in the ground. On Earth, springs (where groundwater comes to the surface) are often found along fault lines. What is most important about this particular Martian gully is that it occurs equatorward of 30 degrees south, which is extremely unusual. The only gully in this crater is the one associated with the fault. It is essentially the site of a spring, now dried up perhaps. This picture is a sub-frame of an image located near 29.1 degrees south latitude, 207.5 degrees west longitude, acquired on Jan. 17, 2005. Figure C: The third picture shows a small crater on the rim of a larger crater. Only a small portion of the wall of this larger crater is captured in the image. Immediately beneath the small crater occurs a group of gullies. The presence of these gullies also supports the groundwater hypothesis because impacting meteors will fracture the rocks into which they form a crater. In this case, there would be an initial set of subsurface fractures caused by the large impact that created the original, large crater. Then, when the smaller crater formed, it would have created additional fractures in its vicinity. These extra fractures would then have provided pathways, or conduits, through which ground water would come to the surface on the wall of the larger crater, thus creating the gullies observed. One might speculate that the group of gullies was formed by the impact that made the small crater, because of the heat and fracturing of rock during the impact process. However, the gullies are much younger than the small crater, the ejecta from the small crater has been largely eroded away or buried, and the crater partially filled, while the gullies appear sharp, crisp and fresh. This is a portion of an image located near 33.9 degrees south latitude, 160 degrees west longitude, acquired on March 31, 2006. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, |
|
Groundwater May be Source fo
…
PIA09031
Sol (our sun)
Mars Orbiter Camera
| Title |
Groundwater May be Source for Erosion in Martian Gullies |
| Original Caption Released with Image |
Since their discovery early during the Mars Global Surveyor's Mars Orbiter Camera investigation, as first reported in June 2000, Martian gullies have presented a puzzle for the Mars science community: what fluid was responsible for the erosion that created the channels, and where did it come from? The gullies seem to be quite young in a geologic sense (millions of years or less), yet modern and geologically-recent Mars is an extremely dry place, where water ice sublimates directly to gas when the temperature is warm enough. Since June 2000, many hypotheses have been discussed at scientific meetings, in the scientific journals and elsewhere. The original June 2000 hypothesis held that the fluid was liquid water (either pure, salty, acidic, etc.) that came to the surface where slopes intersected conduits of groundwater. Such slopes include crater walls, valley walls, hills, massifs and crater central peaks. Later investigators explored the possibility that rather than liquid groundwater, the source was ground ice, which, under some climate conditions, melted to produce liquid runoff. Still others noted that thick mantles covered a fraction of the gully-bearing slopes, suggesting that the mantles were ancient, dust-covered snow or ice packs that might melt at the base to make liquid water runoff. Water was not the only fluid considered by various colleagues, carbon dioxide can be fluid at some pressures and temperatures. Fluid carbon dioxide was also proposed as a candidate fluidizing agent. Even dry mass movement, or land sliding, of unconsolidated granular material can exhibit some fluid-like behavior. Such mass movements were considered as an explanation for the gullies. The presence of channels primarily formed by erosion but also displaying features representing along-channel deposition, such as levees and meanders, and terminal depositional aprons consisting of dozens to hundreds of individual flow lobes, contributed to the general acceptance of the hypothesis that gullies involved the action of liquid water. Throughout the Mars Global Surveyor mission, the Mars Orbiter Camera team continued to image gullies at every opportunity, looking for new gullies, taking higher resolution images of previously identified gullies, and monitoring the gullies for changes that might occur. Among the results of this extensive survey are numerous examples of gullies that have geological relations to other things in their vicinity. This provides support for the hypothesis that the fluid responsible for the gullies came from beneath the ground, either as groundwater or melting of ice in the Martian subsurface. Three of the best examples are presented here. Figure A: The first picture shows a pair of gully channels that emerge, fully-born at nearly their full width, from beneath small overhangs on the north wall of Dao Vallis. These overhangs are probably created by the presence of a hard-rock layer. Liquid, probably water, percolated through permeable, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., layers just beneath these harder, more resistant rock layers. The arrow points to the place where one of the two neighboring channels emerges. This is a sub-frame of an image acquired on Jan. 10, 2006, located near 34.2 degrees south latitude, 268.1 degrees west longitude. The 150-meter scale bar is about 164 yards wide. Figure B: The second picture shows a gully that formed on the wall of a crater that intersected a mare-type ridge. The term, mare, is from the dark volcanic plains of Earth's moon, for example Mare Tranquilitatis was the plain on which the Apollo 11 crew landed in 1969. The lunar maria (maria is the plural form of mare), when viewed from above, have many "wrinkle" ridges. These ridges are the surface expression of thrust faults. The mare-type ridge in the picture shown here is thus the product of faulting, as rocks on the west (left) side of the image were thrust toward the east (right). Finding a gully associated with a fault is excellent evidence for the groundwater hypothesis, because ground water percolates through cracks and pores in the ground. On Earth, springs (where groundwater comes to the surface) are often found along fault lines. What is most important about this particular Martian gully is that it occurs equatorward of 30 degrees south, which is extremely unusual. The only gully in this crater is the one associated with the fault. It is essentially the site of a spring, now dried up perhaps. This picture is a sub-frame of an image located near 29.1 degrees south latitude, 207.5 degrees west longitude, acquired on Jan. 17, 2005. Figure C: The third picture shows a small crater on the rim of a larger crater. Only a small portion of the wall of this larger crater is captured in the image. Immediately beneath the small crater occurs a group of gullies. The presence of these gullies also supports the groundwater hypothesis because impacting meteors will fracture the rocks into which they form a crater. In this case, there would be an initial set of subsurface fractures caused by the large impact that created the original, large crater. Then, when the smaller crater formed, it would have created additional fractures in its vicinity. These extra fractures would then have provided pathways, or conduits, through which ground water would come to the surface on the wall of the larger crater, thus creating the gullies observed. One might speculate that the group of gullies was formed by the impact that made the small crater, because of the heat and fracturing of rock during the impact process. However, the gullies are much younger than the small crater, the ejecta from the small crater has been largely eroded away or buried, and the crater partially filled, while the gullies appear sharp, crisp and fresh. This is a portion of an image located near 33.9 degrees south latitude, 160 degrees west longitude, acquired on March 31, 2006. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, |
|
Groundwater May be Source fo
…
PIA09031
Sol (our sun)
Mars Orbiter Camera
| Title |
Groundwater May be Source for Erosion in Martian Gullies |
| Original Caption Released with Image |
Since their discovery early during the Mars Global Surveyor's Mars Orbiter Camera investigation, as first reported in June 2000, Martian gullies have presented a puzzle for the Mars science community: what fluid was responsible for the erosion that created the channels, and where did it come from? The gullies seem to be quite young in a geologic sense (millions of years or less), yet modern and geologically-recent Mars is an extremely dry place, where water ice sublimates directly to gas when the temperature is warm enough. Since June 2000, many hypotheses have been discussed at scientific meetings, in the scientific journals and elsewhere. The original June 2000 hypothesis held that the fluid was liquid water (either pure, salty, acidic, etc.) that came to the surface where slopes intersected conduits of groundwater. Such slopes include crater walls, valley walls, hills, massifs and crater central peaks. Later investigators explored the possibility that rather than liquid groundwater, the source was ground ice, which, under some climate conditions, melted to produce liquid runoff. Still others noted that thick mantles covered a fraction of the gully-bearing slopes, suggesting that the mantles were ancient, dust-covered snow or ice packs that might melt at the base to make liquid water runoff. Water was not the only fluid considered by various colleagues, carbon dioxide can be fluid at some pressures and temperatures. Fluid carbon dioxide was also proposed as a candidate fluidizing agent. Even dry mass movement, or land sliding, of unconsolidated granular material can exhibit some fluid-like behavior. Such mass movements were considered as an explanation for the gullies. The presence of channels primarily formed by erosion but also displaying features representing along-channel deposition, such as levees and meanders, and terminal depositional aprons consisting of dozens to hundreds of individual flow lobes, contributed to the general acceptance of the hypothesis that gullies involved the action of liquid water. Throughout the Mars Global Surveyor mission, the Mars Orbiter Camera team continued to image gullies at every opportunity, looking for new gullies, taking higher resolution images of previously identified gullies, and monitoring the gullies for changes that might occur. Among the results of this extensive survey are numerous examples of gullies that have geological relations to other things in their vicinity. This provides support for the hypothesis that the fluid responsible for the gullies came from beneath the ground, either as groundwater or melting of ice in the Martian subsurface. Three of the best examples are presented here. Figure A: The first picture shows a pair of gully channels that emerge, fully-born at nearly their full width, from beneath small overhangs on the north wall of Dao Vallis. These overhangs are probably created by the presence of a hard-rock layer. Liquid, probably water, percolated through permeable, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., layers just beneath these harder, more resistant rock layers. The arrow points to the place where one of the two neighboring channels emerges. This is a sub-frame of an image acquired on Jan. 10, 2006, located near 34.2 degrees south latitude, 268.1 degrees west longitude. The 150-meter scale bar is about 164 yards wide. Figure B: The second picture shows a gully that formed on the wall of a crater that intersected a mare-type ridge. The term, mare, is from the dark volcanic plains of Earth's moon, for example Mare Tranquilitatis was the plain on which the Apollo 11 crew landed in 1969. The lunar maria (maria is the plural form of mare), when viewed from above, have many "wrinkle" ridges. These ridges are the surface expression of thrust faults. The mare-type ridge in the picture shown here is thus the product of faulting, as rocks on the west (left) side of the image were thrust toward the east (right). Finding a gully associated with a fault is excellent evidence for the groundwater hypothesis, because ground water percolates through cracks and pores in the ground. On Earth, springs (where groundwater comes to the surface) are often found along fault lines. What is most important about this particular Martian gully is that it occurs equatorward of 30 degrees south, which is extremely unusual. The only gully in this crater is the one associated with the fault. It is essentially the site of a spring, now dried up perhaps. This picture is a sub-frame of an image located near 29.1 degrees south latitude, 207.5 degrees west longitude, acquired on Jan. 17, 2005. Figure C: The third picture shows a small crater on the rim of a larger crater. Only a small portion of the wall of this larger crater is captured in the image. Immediately beneath the small crater occurs a group of gullies. The presence of these gullies also supports the groundwater hypothesis because impacting meteors will fracture the rocks into which they form a crater. In this case, there would be an initial set of subsurface fractures caused by the large impact that created the original, large crater. Then, when the smaller crater formed, it would have created additional fractures in its vicinity. These extra fractures would then have provided pathways, or conduits, through which ground water would come to the surface on the wall of the larger crater, thus creating the gullies observed. One might speculate that the group of gullies was formed by the impact that made the small crater, because of the heat and fracturing of rock during the impact process. However, the gullies are much younger than the small crater, the ejecta from the small crater has been largely eroded away or buried, and the crater partially filled, while the gullies appear sharp, crisp and fresh. This is a portion of an image located near 33.9 degrees south latitude, 160 degrees west longitude, acquired on March 31, 2006. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, |
|
New Craters
PIA09020
Sol (our sun)
Mars Orbiter Camera
| Title |
New Craters |
| Original Caption Released with Image |
Office of Space Science, Washington, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., The Mars Global Surveyor's Mars Orbiter Camera has found that meteorites are hitting the Martian surface and forming new craters all the time. If you were living on Mars, chances are that within 10 or 20 years, an impact would occur close enough to where you live that you'd notice it -- perhaps you'd hear the impact and it would startle you out of your seat. A year ago, it had not occurred to the camera team that they could find places on Mars where meteorites had impacted the surface during the course of the mission. Such craters, if they were forming at all, would be a few meters to a few tens of meters across, much too small to notice (or so they thought) in the wide-angle camera coverage. But, on Jan. 9, 2006, they began to realize that not only could we find such craters, we might also be able to characterize the present-day impact cratering rate on Mars. Surveying for fresh craters formed during the mission would provide the first direct observation -- for any body in the solar system, including Earth and its Moon -- of the present-day cratering rate. This in turn can help test models used all the time by members of the scientific community to estimate the age of features on planetary surfaces. The first fresh impact site, shown on this page, was first noticed on Jan. 9, 2006, in an image acquired three days earlier. The image was acquired by the wide-angle camera at its highest possible spatial resolution, about 240 meters (262 yards) per pixel. To the northwest of the area imaged by the narrow-angle camera, the red, wide-angle context frame showed a dark spot. This spot was not present in any previous image acquired by any spacecraft, from Mariner 9 (which arrived in 1971) on down through Mars Express (which arrived in 2003). Figure A: The first figure shows two red, wide-angle camera context images. The first was taken on June 9, 2001, several years before the impact occurred. The second is the "discovery" image, acquired on January 6, 2006. In both cases, a white box indicates the location of the Mars Orbiter Camera narrow-angle image for which the context image was obtained. For scale, the white boxes are 3 kilometers (1.9 miles) wide. Figure B: In this image, North is up in this map-projected view. The single, broad dark streak that emanates from the impact site and points toward the southwest (lower left) may indicate either the direction that the meteor came from, or its opposite. If it represents the direction that the impactor came from, then the streak results from disruption of dust on the Martian surface as the object came in. If the opposite, then it represents the direction that material was blasted from the impact site, away from the direction that the meteor came. In either case, the impactor came in at a somewhat oblique angle, and broke up just before hitting the ground, because it formed multiple small craters. The 300-meter scale bar represents 328 yards. The Mars Global Surveyor mission is managed for NASA's |
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New Craters
PIA09020
Sol (our sun)
Mars Orbiter Camera
| Title |
New Craters |
| Original Caption Released with Image |
Office of Space Science, Washington, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., The Mars Global Surveyor's Mars Orbiter Camera has found that meteorites are hitting the Martian surface and forming new craters all the time. If you were living on Mars, chances are that within 10 or 20 years, an impact would occur close enough to where you live that you'd notice it -- perhaps you'd hear the impact and it would startle you out of your seat. A year ago, it had not occurred to the camera team that they could find places on Mars where meteorites had impacted the surface during the course of the mission. Such craters, if they were forming at all, would be a few meters to a few tens of meters across, much too small to notice (or so they thought) in the wide-angle camera coverage. But, on Jan. 9, 2006, they began to realize that not only could we find such craters, we might also be able to characterize the present-day impact cratering rate on Mars. Surveying for fresh craters formed during the mission would provide the first direct observation -- for any body in the solar system, including Earth and its Moon -- of the present-day cratering rate. This in turn can help test models used all the time by members of the scientific community to estimate the age of features on planetary surfaces. The first fresh impact site, shown on this page, was first noticed on Jan. 9, 2006, in an image acquired three days earlier. The image was acquired by the wide-angle camera at its highest possible spatial resolution, about 240 meters (262 yards) per pixel. To the northwest of the area imaged by the narrow-angle camera, the red, wide-angle context frame showed a dark spot. This spot was not present in any previous image acquired by any spacecraft, from Mariner 9 (which arrived in 1971) on down through Mars Express (which arrived in 2003). Figure A: The first figure shows two red, wide-angle camera context images. The first was taken on June 9, 2001, several years before the impact occurred. The second is the "discovery" image, acquired on January 6, 2006. In both cases, a white box indicates the location of the Mars Orbiter Camera narrow-angle image for which the context image was obtained. For scale, the white boxes are 3 kilometers (1.9 miles) wide. Figure B: In this image, North is up in this map-projected view. The single, broad dark streak that emanates from the impact site and points toward the southwest (lower left) may indicate either the direction that the meteor came from, or its opposite. If it represents the direction that the impactor came from, then the streak results from disruption of dust on the Martian surface as the object came in. If the opposite, then it represents the direction that material was blasted from the impact site, away from the direction that the meteor came. In either case, the impactor came in at a somewhat oblique angle, and broke up just before hitting the ground, because it formed multiple small craters. The 300-meter scale bar represents 328 yards. The Mars Global Surveyor mission is managed for NASA's |
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New Craters
PIA09020
Sol (our sun)
Mars Orbiter Camera
| Title |
New Craters |
| Original Caption Released with Image |
Office of Space Science, Washington, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., The Mars Global Surveyor's Mars Orbiter Camera has found that meteorites are hitting the Martian surface and forming new craters all the time. If you were living on Mars, chances are that within 10 or 20 years, an impact would occur close enough to where you live that you'd notice it -- perhaps you'd hear the impact and it would startle you out of your seat. A year ago, it had not occurred to the camera team that they could find places on Mars where meteorites had impacted the surface during the course of the mission. Such craters, if they were forming at all, would be a few meters to a few tens of meters across, much too small to notice (or so they thought) in the wide-angle camera coverage. But, on Jan. 9, 2006, they began to realize that not only could we find such craters, we might also be able to characterize the present-day impact cratering rate on Mars. Surveying for fresh craters formed during the mission would provide the first direct observation -- for any body in the solar system, including Earth and its Moon -- of the present-day cratering rate. This in turn can help test models used all the time by members of the scientific community to estimate the age of features on planetary surfaces. The first fresh impact site, shown on this page, was first noticed on Jan. 9, 2006, in an image acquired three days earlier. The image was acquired by the wide-angle camera at its highest possible spatial resolution, about 240 meters (262 yards) per pixel. To the northwest of the area imaged by the narrow-angle camera, the red, wide-angle context frame showed a dark spot. This spot was not present in any previous image acquired by any spacecraft, from Mariner 9 (which arrived in 1971) on down through Mars Express (which arrived in 2003). Figure A: The first figure shows two red, wide-angle camera context images. The first was taken on June 9, 2001, several years before the impact occurred. The second is the "discovery" image, acquired on January 6, 2006. In both cases, a white box indicates the location of the Mars Orbiter Camera narrow-angle image for which the context image was obtained. For scale, the white boxes are 3 kilometers (1.9 miles) wide. Figure B: In this image, North is up in this map-projected view. The single, broad dark streak that emanates from the impact site and points toward the southwest (lower left) may indicate either the direction that the meteor came from, or its opposite. If it represents the direction that the impactor came from, then the streak results from disruption of dust on the Martian surface as the object came in. If the opposite, then it represents the direction that material was blasted from the impact site, away from the direction that the meteor came. In either case, the impactor came in at a somewhat oblique angle, and broke up just before hitting the ground, because it formed multiple small craters. The 300-meter scale bar represents 328 yards. The Mars Global Surveyor mission is managed for NASA's |
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New Craters
PIA09020
Sol (our sun)
Mars Orbiter Camera
| Title |
New Craters |
| Original Caption Released with Image |
Office of Space Science, Washington, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., The Mars Global Surveyor's Mars Orbiter Camera has found that meteorites are hitting the Martian surface and forming new craters all the time. If you were living on Mars, chances are that within 10 or 20 years, an impact would occur close enough to where you live that you'd notice it -- perhaps you'd hear the impact and it would startle you out of your seat. A year ago, it had not occurred to the camera team that they could find places on Mars where meteorites had impacted the surface during the course of the mission. Such craters, if they were forming at all, would be a few meters to a few tens of meters across, much too small to notice (or so they thought) in the wide-angle camera coverage. But, on Jan. 9, 2006, they began to realize that not only could we find such craters, we might also be able to characterize the present-day impact cratering rate on Mars. Surveying for fresh craters formed during the mission would provide the first direct observation -- for any body in the solar system, including Earth and its Moon -- of the present-day cratering rate. This in turn can help test models used all the time by members of the scientific community to estimate the age of features on planetary surfaces. The first fresh impact site, shown on this page, was first noticed on Jan. 9, 2006, in an image acquired three days earlier. The image was acquired by the wide-angle camera at its highest possible spatial resolution, about 240 meters (262 yards) per pixel. To the northwest of the area imaged by the narrow-angle camera, the red, wide-angle context frame showed a dark spot. This spot was not present in any previous image acquired by any spacecraft, from Mariner 9 (which arrived in 1971) on down through Mars Express (which arrived in 2003). Figure A: The first figure shows two red, wide-angle camera context images. The first was taken on June 9, 2001, several years before the impact occurred. The second is the "discovery" image, acquired on January 6, 2006. In both cases, a white box indicates the location of the Mars Orbiter Camera narrow-angle image for which the context image was obtained. For scale, the white boxes are 3 kilometers (1.9 miles) wide. Figure B: In this image, North is up in this map-projected view. The single, broad dark streak that emanates from the impact site and points toward the southwest (lower left) may indicate either the direction that the meteor came from, or its opposite. If it represents the direction that the impactor came from, then the streak results from disruption of dust on the Martian surface as the object came in. If the opposite, then it represents the direction that material was blasted from the impact site, away from the direction that the meteor came. In either case, the impactor came in at a somewhat oblique angle, and broke up just before hitting the ground, because it formed multiple small craters. The 300-meter scale bar represents 328 yards. The Mars Global Surveyor mission is managed for NASA's |
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Full-Frame Reference for Tes
…
PIA08005
Earth
HiRISE
| Title |
Full-Frame Reference for Test Photo of Moon |
| Original Caption Released with Image |
This pair of views shows how little of the full image frame was taken up by the Moon in test images taken Sept. 8, 2005, by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The Mars-bound camera imaged Earth's Moon from a distance of about 10 million kilometers (6 million miles) away -- 26 times the distance between Earth and the Moon -- as part of an activity to test and calibrate the camera. The images are very significant because they show that the Mars Reconnaissance Orbiter spacecraft and this camera can properly operate together to collect very high-resolution images of Mars. The target must move through the camera's telescope view in just the right direction and speed to acquire a proper image. The day's test images also demonstrate that the focus mechanism works properly with the telescope to produce sharp images. Out of the 20,000-pixel-by-6,000-pixel full frame, the Moon's diameter is about 340 pixels, if the full Moon could be seen. The illuminated crescent is about 60 pixels wide, and the resolution is about 10 kilometers (6 miles) per pixel. At Mars, the entire image region will be filled with high-resolution information. The Mars Reconnaissance Orbiter, launched on Aug. 12, 2005, is on course to reach Mars on March 10, 2006. After gradually adjusting the shape of its orbit for half a year, it will begin its primary science phase in November 2006. From the mission's planned science orbit about 300 kilometers (186 miles) above the surface of Mars, the high resolution camera will be able to discern features as small as one meter or yard across. The Mars Reconnaissance Orbiter mission is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for the NASA Science Mission Directorate. Lockheed Martin Space Systems, Denver, prime contractor for the project, built the spacecraft. Ball Aerospace & Technologies Corp., Boulder, Colo., built the High Resolution Imaging Science Experiment instrument for the University of Arizona, Tucson, to provide to the mission. The HiRISE Operations Center at the University of Arizona processes images from the camera. |
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