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Images of Goddard Space Flight Center (GSFC) and Jet Propulsion Laboratory (JPL) from 2005
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A Cauldron of Stars at the G
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| Title |
A Cauldron of Stars at the Galaxy's Center |
| Description |
This dazzling infrared image from NASA's Spitzer Space Telescope shows hundreds of thousands of stars crowded into the swirling core of our spiral Milky Way galaxy. In visible-light pictures, this region cannot be seen at all because dust lying between Earth and the galactic center blocks our view. In this false-color picture, old and cool stars are blue, while dust features lit up by blazing hot, massive stars are shown in a reddish hue. Both bright and dark filamentary clouds can be seen, many of which harbor stellar nurseries. The plane of the Milky Way's flat disk is apparent as the main, horizontal band of clouds. The brightest white spot in the middle is the very center of the galaxy, which also marks the site of a supermassive black hole. The region pictured here is immense, with a horizontal span of 890 light-years and a vertical span of 640 light-years. Earth is located 26,000 light-years away, out in one of the Milky Way's spiral arms. Though most of the objects seen in this image are located at the galactic center, the features above and below the galactic plane tend to lie closer to Earth. Scientists are intrigued by the giant lobes of dust extending away from the plane of the galaxy. They believe the lobes may have been formed by winds from massive stars. This image is a mosaic of thousands of short exposures taken by Spitzer's Infrared Array Camera (IRAC), showing emissions from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange), and 8.0 microns (red). The entire region was imaged in less than 16 hours. |
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A Cauldron of Stars at the G
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| Title |
A Cauldron of Stars at the Galaxy's Center |
| Description |
This dazzling infrared image from NASA's Spitzer Space Telescope shows hundreds of thousands of stars crowded into the swirling core of our spiral Milky Way galaxy. In visible-light pictures, this region cannot be seen at all because dust lying between Earth and the galactic center blocks our view. In this false-color picture, old and cool stars are blue, while dust features lit up by blazing hot, massive stars are shown in a reddish hue. Both bright and dark filamentary clouds can be seen, many of which harbor stellar nurseries. The plane of the Milky Way's flat disk is apparent as the main, horizontal band of clouds. The brightest white spot in the middle is the very center of the galaxy, which also marks the site of a supermassive black hole. The region pictured here is immense, with a horizontal span of 890 light-years and a vertical span of 640 light-years. Earth is located 26,000 light-years away, out in one of the Milky Way's spiral arms. Though most of the objects seen in this image are located at the galactic center, the features above and below the galactic plane tend to lie closer to Earth. Scientists are intrigued by the giant lobes of dust extending away from the plane of the galaxy. They believe the lobes may have been formed by winds from massive stars. This image is a mosaic of thousands of short exposures taken by Spitzer's Infrared Array Camera (IRAC), showing emissions from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange), and 8.0 microns (red). The entire region was imaged in less than 16 hours. |
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The Milky Way Center Aglow w
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| Title |
The Milky Way Center Aglow with Dust |
| Description |
Our Milky Way is a dusty place. So dusty, in fact, that we cannot see the center of the galaxy in visible light. But when NASA's Spitzer Space Telescope set its infrared eyes on the galactic center, it captured this spectacular view. Taken with just one of Spitzer's cameras (at a wavelength of 8 microns), the image highlights the region's exceptionally bright and dusty clouds, lit up by young massive stars. Individual stars can also be seen as tiny dots scattered throughout the dust. The top mosaic shows a portion of the galactic center that stretches across a distance of 760 light-years. Thanks to Spitzer's excellent resolution, the dusty features within the galactic center are seen in unprecedented detail. Four examples are shown in the magnified insets at the bottom. The farthest left box shows a pair of star-forming regions resembling owl-like cosmic eyes. To the left of the "eyes," dark lanes of dust can be seen. This object is probably located in a spiral arm between Earth and the galactic center, in contrast to the following examples, which are all located at the galactic center. The next inset to the right includes the extremely luminous "Quintuplet" stars, a set of five massive stars believed to have buried themselves in cocoons of dust. Just below and to the right of the Quintuplet is the "Pistol" nebula, a bubble of ejected material from the central, massive Pistol star. The finger-like pillars to the left are part of a structure known as "Sickle." They are similar in size and shape to those in the famous picture of the Eagle Nebula taken by NASA's Hubble Space Telescope. Pillars like these are sculpted out of dense dust clouds by radiation and winds from hot stars. The pillars in the Sickle were likely to have been formed by a cluster of hot stars located to their right but not readily visible here. The third inset highlights a system of long, stringy structures that are seen for the first time near the base of a region known as the "Arched Filaments." These long filaments are about 10 light-years long and less than 1 light-year wide. The bright star-forming regions to the right are some of the brightest in the infrared sky. The final inset to the right shows the center of our galaxy, which is the brightest spot in the entire mosaic. The brightness is a result of dust being heated up by a compact cluster of hot stars. The bright spot also marks the location of a supermassive black hole, around which a rotating ring of gas and dust known as the circumnuclear disk can be seen. This image was taken with Spitzer's Infrared Array Camera (IRAC), using its 8-micron detector. It shows emissions from heated-up molecules in dust clouds called polycyclic aromatic hydrocarbons. |
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The Milky Way Center Aglow w
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| Title |
The Milky Way Center Aglow with Dust |
| Description |
Our Milky Way is a dusty place. So dusty, in fact, that we cannot see the center of the galaxy in visible light. But when NASA's Spitzer Space Telescope set its infrared eyes on the galactic center, it captured this spectacular view. Taken with just one of Spitzer's cameras (at a wavelength of 8 microns), the image highlights the region's exceptionally bright and dusty clouds, lit up by young massive stars. Individual stars can also be seen as tiny dots scattered throughout the dust. The top mosaic shows a portion of the galactic center that stretches across a distance of 760 light-years. Thanks to Spitzer's excellent resolution, the dusty features within the galactic center are seen in unprecedented detail. Four examples are shown in the magnified insets at the bottom. The farthest left box shows a pair of star-forming regions resembling owl-like cosmic eyes. To the left of the "eyes," dark lanes of dust can be seen. This object is probably located in a spiral arm between Earth and the galactic center, in contrast to the following examples, which are all located at the galactic center. The next inset to the right includes the extremely luminous "Quintuplet" stars, a set of five massive stars believed to have buried themselves in cocoons of dust. Just below and to the right of the Quintuplet is the "Pistol" nebula, a bubble of ejected material from the central, massive Pistol star. The finger-like pillars to the left are part of a structure known as "Sickle." They are similar in size and shape to those in the famous picture of the Eagle Nebula taken by NASA's Hubble Space Telescope. Pillars like these are sculpted out of dense dust clouds by radiation and winds from hot stars. The pillars in the Sickle were likely to have been formed by a cluster of hot stars located to their right but not readily visible here. The third inset highlights a system of long, stringy structures that are seen for the first time near the base of a region known as the "Arched Filaments." These long filaments are about 10 light-years long and less than 1 light-year wide. The bright star-forming regions to the right are some of the brightest in the infrared sky. The final inset to the right shows the center of our galaxy, which is the brightest spot in the entire mosaic. The brightness is a result of dust being heated up by a compact cluster of hot stars. The bright spot also marks the location of a supermassive black hole, around which a rotating ring of gas and dust known as the circumnuclear disk can be seen. This image was taken with Spitzer's Infrared Array Camera (IRAC), using its 8-micron detector. It shows emissions from heated-up molecules in dust clouds called polycyclic aromatic hydrocarbons. |
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Iapetus Thermal Radiation Im
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| Description |
Iapetus Thermal Radiation Image |
| Full Description |
This image of the infrared heat radiation from Saturn's moon Iapetus was obtained by the Cassini composite infrared spectrometer instrument 16 hours before Cassini's closest approach to this mysterious moon, on December 31, 2004. The thermal radiation is shown as both a grayscale image, equivalent to what we would see if our eyes were sensitive to infrared wavelengths near 15 microns, and as a color-coded temperature map. A previously-released mosaic obtained by Cassini's imaging camera shortly before the composite infrared spectrometer observation, with similar scale and orientation, is also shown for comparison. Temperatures reach nearly 130 Kelvin (-226 Fahrenheit) at noon on the equator on the dark material that covers most of this side of Iapetus, making high noon on Iapetus's dark side probably the warmest places in the Saturn system. This is much warmer than temperatures on another Saturnian moon, Phoebe, measured by composite infrared spectrometer in June 2004. Those Phoebe temperature measurements peaked near 112 Kelvin (-258 Fahrenheit), because though Phoebe is almost as dark as Iapetus's dark material and absorbs nearly as much sunlight, Phoebe rotates much more quickly (once every 9 hours, compared to 79 days for Iapetus). That means the surface has less time to heat up during the day. Temperatures on Iapetus's bright material are much colder, peaking near 100 Kelvin (-280 Fahrenheit), both because the bright material absorbs less sunlight and because it is further from the equator on this side of Iapetus. Temperatures in the large crater near the center of the disc are slightly different from those in surrounding areas, because sloping surfaces within the crater are warmer where they are tilted towards the Sun and cooler when tilted away from the Sun. 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 composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov/. *Credit*: NASA/JPL/GSFC |
| Date |
January 10, 2005 |
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Iapetus Surface Composition
| Description |
Iapetus Surface Composition |
| Full Description |
The Cassini visual and infrared mapping spectrometer analyzed the surface composition of Saturn's moon Iapetus as Cassini flew over the polar region on Dec. 31, 2004. The image at left shows the reflectance at 4-microns, which is dominated by the minerals on Iapetus' surface. Two large craters are seen in this image. The polar water ice is relatively dark at this wavelength, so the ice cap is not seen. The next frame shows carbon dioxide on the surface. The carbon dioxide peaks at mid latitudes and shows less strength at the pole and along the equator (the dark band curving near the left edge of the image). The third frame shows the strength of water absorption on Iapetus. The brightest regions are due to water ice near the pole. The grayer areas indicate water bound to minerals on the surface. The color composite shows water as blue, carbon dioxide as green, and non-ice minerals as red. 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 visible and infrared mapping spectrometer team is based at the University of Arizona, Tucson. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov. For more information about the visual and infrared mapping spectrometer visit http://wwwvims.lpl.arizona.edu/. *Credit*: NASA/JPL/GSFC |
| Date |
January 10, 2005 |
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Iapetus Temperature Variatio
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| Description |
Iapetus Temperature Variation Map |
| Full Description |
This plot shows how daytime temperatures at low latitudes on the dark material on Saturn's moon Iapetus vary with time of day, from about 130 Kelvin (-226 Fahrenheit) at noon to about 70 Kelvin (-334 Fahrenheit) at sunset. The observations are compared to a "forecast" model (green line) which predicts temperatures based on an assumed value of a parameter called the "thermal inertia. This measures how well the surface can retain heat as conditions change. Rock or solid ice has a high thermal inertia, roughly 2,000,000 as measured in the obscure units used for thermal inertia, meaning that it is good at storing heat and cools down or heats up relatively slowly. On Iapetus, in contrast, temperatures drop precipitously in the afternoon as the Sun sinks towards the horizon, and a very small value of the thermal inertia (30,000 units) is needed in the model to match the data. This means that Iapetus's surface is extremely bad at storing heat, and is thus extremely fluffy, probably due to the pulverizing effect of billions of years of meteorite impacts, though the mysterious process that has darkened this side of Iapetus may also have played a role. 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 composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov/. *Credit*: NASA/JPL/GSFC |
| Date |
January 10, 2005 |
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Enceladus Keeps the Home Fir
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| Description |
Enceladus Keeps the Home Fires Burning |
| Full Description |
On Nov. 9, 2006, Cassini's composite infrared spectrometer captured its first view of the infrared heat radiation emanating from the "tiger stripe" fractures at the south pole of Saturn's moon Enceladus (right) since the discovery of the hot spot 16 months earlier (left). The original discovery was made just before a close flyby of Enceladus on July 14, 2005, and coincided with the discovery of plumes of water-rich gas and ice particles jetting out of the tiger stripes. However, the spacecraft's orbit did not provide any good views of the south pole for follow-up observations until November 2006. The new observations were made from a range of 110,000 kilometers (68,350 miles), slightly more distant than the 80,000-kilometer range (49,700 miles) of the original observations. Comparison of the two images shows that the south polar region continues to be active, and the distribution of temperatures there has changed little in 16 months. The distribution of heat radiation suggests that most or all of the south polar heat comes from the tiger stripes themselves, though the individual stripes are not resolved at the approximate 30-kilometer (19-mile) spatial resolution of these images. The images show the intensity of heat radiation in the 10- to 16-micron wavelength range, translated into temperature and displayed in false color. Peak south polar temperature on both dates reached about 85 Kelvin (minus 306 degrees Fahrenheit), averaged over the 30-kilometer (19-mile) spatial resolution of the data. However, the variation in brightness with wavelength, which is also measured by the composite infrared spectrometer, reveals that the warm region includes small areas, possibly zones a few 100 meters (320 feet) wide along the length of the tiger stripes, that are at higher temperatures, reaching at least 130 Kelvin (minus 225 degrees Fahrenheit) and perhaps much warmer still. While the south polar tiger stripes are almost certainly heated by energy from the moon's interior, daytime regions at low latitudes are warmed by sunlight to temperatures in the high 70s Kelvin (about minus 320 degrees Fahrenheit). The white numbers on the images show west longitudes on Enceladus, which is 500 kilometers (310 miles) in diameter. The dashed line shows the terminator, the boundary between day and night. The blotchy appearance of the cooler regions away from the south pole, and of the sky beyond the globe of Enceladus, is an artifact resulting from the fact that apart from the polar hot spot, the composite infrared spectrometer can barely detect the very faint heat radiation from this very cold moon. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The, composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. *Image Credit:* NASA/JPL/GSFC/Southwest Research Institute |
| Date |
December 22, 2006 |
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SOHO Watches Saturn and Cass
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| Description |
SOHO Watches Saturn and Cassini Pass Behind the Sun |
| Full Description |
In this SOHO image taken July 21, 2005, the Sun is represented by the white circle in the center. Saturn is the bright object to the left of the Sun. Interestingly, the streak accompanying Saturn is not the rings but a distortion caused by Saturn's brightness. Saturn is approaching "superior conjunction," that is, it will be almost directly behind the Sun from Earth -- thus the Cassini spacecraft, in orbit around Saturn, will not be able to send or receive transmissions normally. Regular science data collection has been temporarily suspended. As Cassini passes closest by the limb (edge) of the Sun on July 24 PDT, communications will be impossible because of the Sun's radio noise. The spacecraft will regain full communication with Earth on July 27, once again returning Saturn science data. In the meantime, controllers are sending approximately 100 commands per day to test communication status. Cassini radio scientists are taking advantage of this opportunity to study the Sun's corona from its effects on the radio signals that reach Earth. SOHO (Solar and Heliospheric Observatory Satellite) orbits the Sun parked in one of the five gravitational-neutral spots, called Lagrange Points. This specific spot, called L1, stays in the same place relative to the Sun and the Earth, offering a continuously uninterrupted view of the Sun. Saturn is not in sight again until the evening of July 24. After that date, it will be to the RIGHT of the sun. For more information on "superior conjunction," visit: http://www.jpl.nasa.gov/basics/bsf1-2.html#conj . For more information on the Lagrange Points, visit: http://map.gsfc.nasa.gov/m_mm/ob_techorbit1.html For more information on SOHO, visit: http://sohowww.nascom.nasa.gov/ . Finally, the latest SOHO images are available at: http://sohowww.nascom.nasa.gov/data/realtime/c3/1024/latest.gif . Credit: SOHO -- http://sohowww.nascom.nasa.gov/ |
| Date |
July 22, 2005 |
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SOHO Watches Saturn and Cass
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| Description |
SOHO Watches Saturn and Cassini Pass Behind the Sun |
| Full Description |
In this SOHO image taken July 21, 2005, the Sun is represented by the white circle in the center. Saturn is the bright object to the left of the Sun. Interestingly, the streak accompanying Saturn is not the rings but a distortion caused by Saturn's brightness. Saturn is approaching "superior conjunction," that is, it will be almost directly behind the Sun from Earth -- thus the Cassini spacecraft, in orbit around Saturn, will not be able to send or receive transmissions normally. Regular science data collection has been temporarily suspended. As Cassini passes closest by the limb (edge) of the Sun on July 24 PDT, communications will be impossible because of the Sun's radio noise. The spacecraft will regain full communication with Earth on July 27, once again returning Saturn science data. In the meantime, controllers are sending approximately 100 commands per day to test communication status. Cassini radio scientists are taking advantage of this opportunity to study the Sun's corona from its effects on the radio signals that reach Earth. SOHO (Solar and Heliospheric Observatory Satellite) orbits the Sun parked in one of the five gravitational-neutral spots, called Lagrange Points. This specific spot, called L1, stays in the same place relative to the Sun and the Earth, offering a continuously uninterrupted view of the Sun. Saturn is not in sight again until the evening of July 24. After that date, it will be to the RIGHT of the sun. For more information on "superior conjunction," visit: http://www.jpl.nasa.gov/basics/bsf1-2.html#conj . For more information on the Lagrange Points, visit: http://map.gsfc.nasa.gov/m_mm/ob_techorbit1.html For more information on SOHO, visit: http://sohowww.nascom.nasa.gov/ . Finally, the latest SOHO images are available at: http://sohowww.nascom.nasa.gov/data/realtime/c3/1024/latest.gif . Credit: SOHO -- http://sohowww.nascom.nasa.gov/ |
| Date |
July 22, 2005 |
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Warm Fractures on Enceladus
| Description |
Warm Fractures on Enceladus |
| Full Description |
This image shows the warmest places in the south polar region of Saturn's moon Enceladus. The unexpected temperatures were discovered by Cassini's composite infrared spectrometer during a close flyby on July 14, 2005. The image shows how these temperatures correspond to the prominent, bluish fractures dubbed "tiger stripes," first imaged by Cassini's imaging science subsystem cameras. Working together the two teams were able to pinpoint the exact location of the warmest regions on Enceladus. The composite infrared spectrometer instrument measured the infrared heat radiation from the surface at wavelengths between 9 and 16.5 microns within each of the 10 squares shown here. Each square is 6 kilometers (4 miles) across. The color of each square, and the number shown above it, describe the composite infrared spectrometer's measurement of the approximate average temperature of the surface within that square. The warmest temperature squares, at 91 and 89 degrees Kelvin (minus 296 and minus 299 degrees Fahrenheit), are located over one of the "tiger stripe" fractures. They contrast sharply with the surrounding temperatures, which are in the range 74 to 81 degrees Kelvin (minus 326 to minus 313 degrees Fahrenheit). The detailed composite infrared spectrometer data suggest that small areas near the fracture are at substantially higher temperatures, well over 100 degrees Kelvin (minus 279 degrees Fahrenheit). Such "warm" temperatures are unlikely to be due to heating of the surface by the feeble sunlight striking Enceladus' south pole. They are a strong indication that internal heat is leaking out of Enceladus and warming the surface along these fractures. Evaporation of this relatively warm ice probably generates the cloud of water vapor detected above Enceladus' south pole by several other Cassini instruments. Scientists are unsure how the internal heat reaches the surface. The process might involve liquid water, slushy brine, or soft but solid ice. The imaging science subsystem image is an enhanced color view with a pixel scale of 122 meters (400 feet) that was acquired at the same time as the composite infrared spectrometer data. It covers a region 125 kilometers (75 miles) across. The spacecraft's distance from Enceladus was 21,000 kilometers (13,000 miles). The broad bluer fractures that can be seen running from the upper left to the lower right of the image are 1 to 2 kilometers (0.6 to 1.2 miles) wide and more than 100 kilometers (60 miles) long. The fractures are thought to be bluer than the surrounding surface because coarser-grained ice (which has a blue color just as thick masses of ice, like glaciers and icebergs, do on Earth) has been exposed in the fractures. The color image was constructed using an ultraviolet filter (centered at 338 nanometers) in the blue channel, a clear filter in the green channel, and an infrared filter (centered at 930 nanometers) in the red channel. The Cassini-Huygens mission is a cooperative project of NASA,, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/ . The imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/GSFC/Space Science Institute |
| Date |
July 29, 2005 |
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Enceladus Temperature Map
| Description |
Enceladus Temperature Map |
| Full Description |
This image shows the surprise that startled Cassini scientists on the composite infrared spectrometer team when they got their first look at the infrared (heat) radiation from the south pole of Saturn's moon Enceladus. There is a dramatic warm spot centered on the pole that is probably a sign of internal heat leaking out of the icy moon. The data were taken during the spacecraft's third flyby of this intriguing moon on July 14, 2005. Based on data from previous flybys, which did not show the south pole well, team members expected that the south pole would be very cold, as shown in the left panel. Enceladus is one of the coldest places in the Saturn system because its extremely bright surface reflects 80 percent of the sunlight that hits it, so only 20 percent is available to heat the surface. As on Earth, the poles should be even colder than the equator because the sun shines at such an oblique angle there. The right hand panel shows a global temperature image made from measurements of Enceladus' heat radiation at wavelengths between 9 and 16.5 microns. Cassini made the observation from a distance of 84,000 kilometers (52,000 miles) on the approach to Enceladus, and the image shows details as small as 25 kilometers (16 miles). Equatorial temperatures are much as expected, topping out at about 80 degrees Kelvin (-315 degrees Fahrenheit), but the south pole is occupied by a well-defined warm region reaching 85 Kelvin (-305 degrees Fahrenheit). That is 15 degrees Kelvin (27 degrees Fahrenheit) warmer than expected. The composite infrared spectrometer data further suggest that small areas of the pole are at even higher temperatures, well over 110 degrees Kelvin (-261 degrees Fahrenheit). Evaporation of this relatively warm ice probably generates the cloud of water vapor detected above Enceladus' south pole by several other Cassini instruments. The south polar temperatures are very difficult to explain if sunlight is the only energy source heating the surface, though exotic sunlight-trapping mechanisms have not yet been completely ruled out. It therefore seems likely that portions of the polar region are warmed by heat escaping from the interior of the moon. This would make Enceladus only the third solid body in the solar system, after Earth and Jupiter's volcanic moon Io, where hot spots powered by internal heat have been detected. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The composite infrared spectrometer team homepage is, http://cirs.gsfc.nasa.gov/ . Credit: NASA/JPL/GSFC |
| Date |
July 29, 2005 |
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Slower Spinning Rings #1
| Description |
Slower Spinning Rings #1 |
| Full Description |
The Cassini composite infrared spectrometer obtained temperature maps of Saturn's main rings (A, B and C) that showed ring temperatures decreasing with increasing solar phase angle (the change of the sun-spacecraft-ring angle) on both the lit and unlit sides of the rings. Temperature changes throughout Saturn's main rings, as measured by the instrument, indicate that Saturn ring particles spin slowly compared to their orbital periods of 6 to 14 hours. They may spin several times per orbit to less than one time per orbit. Scans are shown for the lit and unlit rings, at relatively low (less than 60-degree) and high (more than 130-degree) phase angles. Each scan was painted on the rings at the correct ring orientation, creating a false color image. Warmer temperatures about minus 262 degrees Fahrenheit (110 Kelvin) are shown in red and cooler temperatures about minus 343 degrees (65 K) are shown in blue. Other colors indicate temperatures between minus 343 degrees and minus 262 degrees (65 K and 110 K). The scans of the lit rings are shown in the two panels on the left and scans of the unlit rings are shown in the two panels on the right. The thermal characteristics of each main ring vary noticeably with phase angle. Radial scans of the A, B and C rings show a decrease in temperature with increasing phase angle for both the lit and unlit sides of the rings. The C ring and Cassini Division exhibit the largest change in temperature. The temperature of the lit C ring decreases by about 22 degrees (12 Kelvin) between low and high phase angles. A similar contrast is present for the unlit side of the C ring. The C ring and Cassini Division are darker than the A and B rings so they can absorb more heat from the Sun. The lit B ring shows a temperature contrast of approximately 18 degrees (10 K) while the unlit B ring shows very little thermal contrast. Very little sunlight may make it through the thick B ring to its unlit side. The lit A ring is particularly interesting because the magnitude of the thermal contrast decreases with increasing radial distance from Saturn. The outer A ring shows only a small temperature change with phase angle, possibly because it contains smaller, or more rapidly rotating ring particles, which would have more uniform temperatures with phase angle. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov/. Credit: NASA/JPL/GSFC |
| Date |
September 5, 2005 |
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Slower Spinning Rings #2
| Description |
Slower Spinning Rings #2 |
| Full Description |
Temperature changes mapped with Cassini's composite and infrared spectrometer throughout Saturn's main rings show the ring temperatures decreasing with the increase of the Sun-spacecraft-ring angle (called phase angle) on both the lit and unlit sides of the rings. These temperature changes indicate that the ring particles spin slowly compared to their orbital periods of 6 to 14 hours. They may spin several times per orbit to less than one time per orbit. Four scans are shown for the lit and unlit rings, at relatively low (less than 60 degrees) and high (more than 130 degrees) phase angles. Warmer temperatures about minus 262 degrees Fahrenheit (110 Kelvin) are shown in red and cooler temperatures about minus 343 degrees (65 K) are shown in blue. Other colors indicate temperatures between minus 343 degrees and minus 262 degrees (65 K and 110 K). The top two scans are for the lit rings and the bottom two scans are for the unlit rings. The change in ring temperature between each scan can be seen clearly. The thermal characteristics of each main ring vary noticeably with phase angle. Radial scans of the A, B and C rings show a decrease in temperature with increasing phase angle for both the lit and unlit sides of the rings. The C ring and Cassini Division exhibit the largest change in temperature. The temperature of the lit C ring decreases by about 22 degrees (12 Kelvin) between low and high phase angles. A similar contrast is present for the unlit side of the C ring. The C ring and Cassini Division are darker than the A and B rings so they can absorb more heat from the Sun. The lit B ring shows a temperature contrast of approximately 18 degrees (10 K) while the unlit B ring shows very little thermal contrast. Very little sunlight may make it through the thick B ring to its unlit side. The lit A ring is particularly interesting because the magnitude of the thermal contrast decreases with increasing radial distance from Saturn. The outer A ring shows only a small temperature change with phase angle, possibly because it contains smaller, or more rapidly rotating ring particles, which would have more uniform temperatures with phase angle. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov/. |
| Date |
September 5, 2005 |
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Iapetus Temperature Map
| Description |
Iapetus Temperature Map |
| Full Description |
This temperature map of Saturn's moon Iapetus is constructed from observations of Iapetus's infrared heat radiation taken with the Cassini composite infrared spectrometer instrument during the Dec. 31, 2004 flyby. The orange asterisk marks the point on Iapetus where the Sun is directly overhead. Temperatures reach nearly 130 Kelvin (-226 Fahrenheit) at noon on the equator on the dark material that covers most of this side of Iapetus, making high noon on Iapetus's dark side probably the warmest places in the Saturn system. This is much warmer than temperatures on the moon Phoebe measured by the composite infrared spectrometer in June 2004, which peaked near 112 Kelvin (-258 Fahrenheit). That's because, although Phoebe is almost as dark as Iapetus's dark material and absorbs nearly as much sunlight, Phoebe rotates much more quickly (once every 9 hours, compared to 79 days for Iapetus). That means the surface has less time to heat up during the day. Temperatures on Iapetus' bright material are much colder, peaking near 100 Kelvin (-280 Fahrenheit), both because the bright material absorbs less sunlight and because it is further from the equator on this side of Iapetus. 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 composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov/. *Credit*: NASA/JPL/GSFC |
| Date |
January 10, 2005 |
|
Searching for Warmth
| Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. |
| Full Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by the composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is most strongly seen in the left-most composite infrared spectrometer field of view, which includes a fissure near the end of one of the tiger stripes. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See (PIA07794) for a related image. This image is centered near longitude 135 west, latitude 65 south, and each square from the composite infrared spectrometer field of view is 17.5 kilometers (10.9 miles) across. This Cassini narrow-angle camera image has been cropped and resized for presentation. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. The imaging team homepage is at http://ciclops.org *Credit:* NASA/JPL/GSFC/Space Science Institute |
| Date |
March 9, 2006 |
|
Searching for Warmth
| Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. |
| Full Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is near the center of the composite infrared spectrometer array, directly over a tiger stripe fissure. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite and infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See (PIA07793) for a related image. This image was taken nearly three times closer to the moon and is centered near longitude 120 west, latitude 82 south, and each composite infrared spectrometer field of view is 6.0 kilometers (3.7 miles) across. This Cassini narrow-angle camera image was cropped and resized for presentation. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. The imaging team homepage is at http://ciclops.org *Credit:* NASA/JPL/GSFC/Space Science Institute |
| Date |
March 9, 2006 |
|
Home Reef Reborn
| title |
Home Reef Reborn |
| description |
In the South Pacific, south of Late Island along the Tofua volcanic arc in Tonga, the volcanic island Home Reef is being re-born. The island is thought to have emerged after a volcanic eruption in mid-August that also spewed large amounts of floating pumice into Tongan waters and swept across to Fiji about 350 km (220 miles) to the west of where the new island formed. In 2004, a similar eruption created an ephemeral island about 0.5 by 1.5 km (0.3 by 0.9 miles) in size, it was no longer visible in an ASTER image acquired November 2005. This simulated natural color image shows the vegetation-covered stratovolcanic island of Late Island in the upper right. Home Reef is found in the lower left. The two bluish plumes are hot seawater that is laden with volcanic ash and chemicals, the larger one can be traced for more than 14 km (8.4 miles) to the east. The image was acquired Oct. 10, 2006 and covers an area of 24.3 by 30.2 km. It is located at 18.9 degrees south latitude, 174.7 degrees west longitude. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitors the changing surface of our planet. It is one of five Earth-observing instruments launched Dec. 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Image credit: NASA/GSFC/METI/ERSDAC/JAROS and U.S./Japan ASTER Science Team |
|
Colima Erupts
| Title |
Colima Erupts |
| Description |
A series of explosive eruptions have thundered from the Colima Volcano, Mexico?s most active volcano. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of the Colima volcano on June 3, 2005, just hours after two spectacular eruptions rumbled from the volcano. Two days later, on June 5, Colima experienced its strongest eruption in 20 years when it sent a dark column of ash more than five kilometers into the atmosphere at a rate of roughly 30 kilometers per hour, reports the Universidad de Colima?s Observatorio Vulcanologico [ http://www.ucol.mx/volcan/ ]. Colima also erupted on May 24 and May 30, and the ash from these and the June 2 and June 3 eruptions is clearly visible in the top image. A grey river of ash and rock flows down the west side of the peak, covering the vegetation that was visible on February 6, 2003, lower image. In these false-color images, the dense vegetation that surrounds the volcano is red. A light dusting of ash blankets the trees on the southeast side of the volcano, and fresh flows stream down all sides of the volcano. Because of its resemblance to the cloud in the upper right corner of the image, the cloud that rests over the summit of the volcano is probably a regular cloud, though it could also be a plume of steam. NASA image created by Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov ] |
|
Colima Erupts
| Title |
Colima Erupts |
| Description |
A series of explosive eruptions have thundered from the Colima Volcano, Mexico?s most active volcano. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of the Colima volcano on June 3, 2005, just hours after two spectacular eruptions rumbled from the volcano. Two days later, on June 5, Colima experienced its strongest eruption in 20 years when it sent a dark column of ash more than five kilometers into the atmosphere at a rate of roughly 30 kilometers per hour, reports the Universidad de Colima?s Observatorio Vulcanologico [ http://www.ucol.mx/volcan/ ]. Colima also erupted on May 24 and May 30, and the ash from these and the June 2 and June 3 eruptions is clearly visible in the top image. A grey river of ash and rock flows down the west side of the peak, covering the vegetation that was visible on February 6, 2003, lower image. In these false-color images, the dense vegetation that surrounds the volcano is red. A light dusting of ash blankets the trees on the southeast side of the volcano, and fresh flows stream down all sides of the volcano. Because of its resemblance to the cloud in the upper right corner of the image, the cloud that rests over the summit of the volcano is probably a regular cloud, though it could also be a plume of steam. NASA image created by Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov ] |
|
Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Gulf Coast cities weren't the only land surfaces to take a beating from Hurricane Katrina in August 2005. Barrier islands stretching from Texas to Florida were also scoured by the wind and waves of the powerful storm. Permanent changes to the shape and elevation of Timbalier Island and its northeastern companions are visible in this pair of infrared-enhanced images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite. Timbalier Island, the largest island pictured here, sits at the interface between the Gulf of Mexico (south) and Terrebonne Bay (north) along the Louisiana coast southwest of New Orleans. Compared to the image from 2000 (bottom), a large swath of bright sand dominates the eastern side of Timbalier Island in the September 13 image, having either been piled there or exposed by waves and storm surge. To the east-northeast, two small, curving islands have disappeared completely, while farther north, the fierce seas turned two small slots in a barrier island into a single large gap. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
|
Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Gulf Coast cities weren't the only land surfaces to take a beating from Hurricane Katrina in August 2005. Barrier islands stretching from Texas to Florida were also scoured by the wind and waves of the powerful storm. Permanent changes to the shape and elevation of Timbalier Island and its northeastern companions are visible in this pair of infrared-enhanced images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite. Timbalier Island, the largest island pictured here, sits at the interface between the Gulf of Mexico (south) and Terrebonne Bay (north) along the Louisiana coast southwest of New Orleans. Compared to the image from 2000 (bottom), a large swath of bright sand dominates the eastern side of Timbalier Island in the September 13 image, having either been piled there or exposed by waves and storm surge. To the east-northeast, two small, curving islands have disappeared completely, while farther north, the fierce seas turned two small slots in a barrier island into a single large gap. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
|
Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Gulf Coast cities weren't the only land surfaces to take a beating from Hurricane Katrina in August 2005. Barrier islands stretching from Texas to Florida were also scoured by the wind and waves of the powerful storm. Permanent changes to the shape and elevation of Horn and Petit Bois Islands south of Pascagoula, Mississippi, are visible in these infrared-enhanced images captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite. The eastern and western tips of Horn island have been eroded so greatly that they are now below sea level, their white sandy beaches (August 7 image) now covered by blue water (September 17 image). The sound (northern) side of the island is layered with sand, which stands out in grayish-white against the red of vegetation. On Petit Bois Island, the changes appear more subtle, but there, too, the red of the island's vegetation appears softened by bright sand. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
|
Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Gulf Coast cities weren't the only land surfaces to take a beating from Hurricane Katrina in August 2005. Barrier islands stretching from Texas to Florida were also scoured by the wind and waves of the powerful storm. Permanent changes to the shape and elevation of Horn and Petit Bois Islands south of Pascagoula, Mississippi, are visible in these infrared-enhanced images captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite. The eastern and western tips of Horn island have been eroded so greatly that they are now below sea level, their white sandy beaches (August 7 image) now covered by blue water (September 17 image). The sound (northern) side of the island is layered with sand, which stands out in grayish-white against the red of vegetation. On Petit Bois Island, the changes appear more subtle, but there, too, the red of the island's vegetation appears softened by bright sand. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
|
Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
A fringe of barrier islands line the coast of Mississippi, protecting the mainland from the pounding waves of most ocean storms, but the islands could not shelter the mainland from Hurricane Katrina's exceptionally powerful storm surge. The battering waves ate away at the islands, permanently altering their shape. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of East and West Ship Islands and Cat Island on September 8, 2005. The lower image is made up of two difference ASTER scenes. The scene on the left was acquired on June 4, 2005, while the scene on the right was taken on April 22, 2001. A diagonal line where the ocean changes color indicates the division between the two images. The most dramatic change can be seen in East Ship Island. Compared to April 2001, most of East Ship Island has disappeared beneath the ocean by September 8, 2005. Some of the erosion may have occurred in other storms between 2001 and 2005, but Katrina is probably responsible for much of the damage. The ghost shores of the island are faintly visible under the water as a lighter shade of blue. West Ship Island, which hosts a civil war fort and a historic lighthouse, and Cat Island have also shrunk slightly. The southern tip of Cat Island is missing and the pointed tips of Ship Island have been rounded out. The section of the northwestern shore that holds the lighthouse and fort seems to be unchanged. East and West Ship Islands are no strangers to the type of erosion Katrina inflicted on them. The islands had been a single island until Hurricane Camille cleft it in two in 1969. In general, barrier islands are constantly changing, their shorelines building and eroding at remarkable speed, with dramatic change occurring routinely when powerful storms strike. In competition with nature, humans also have a large impact on barrier islands. Such islands are popular vacation spots. Construction can interfere with beach building and can degrade the vegetation that anchors dunes on the islands. Of the barrier islands along the U.S. coast, East Ship Island is one of the few that remains in its natural state, unchanged by population. To preserve the islands, Congress added them to Gulf Islands National Seashore [ http://www.nps.gov/guis/extended/MIS/MNature/Islands.htm ], the United States' largest national seashore, under the National Park Service. Cat Island forms the western boundary of the park, which consists of a string of islands along the Mississippi and Florida coasts, including East and West Ship Island. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
|
Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
A fringe of barrier islands line the coast of Mississippi, protecting the mainland from the pounding waves of most ocean storms, but the islands could not shelter the mainland from Hurricane Katrina's exceptionally powerful storm surge. The battering waves ate away at the islands, permanently altering their shape. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of East and West Ship Islands and Cat Island on September 8, 2005. The lower image is made up of two difference ASTER scenes. The scene on the left was acquired on June 4, 2005, while the scene on the right was taken on April 22, 2001. A diagonal line where the ocean changes color indicates the division between the two images. The most dramatic change can be seen in East Ship Island. Compared to April 2001, most of East Ship Island has disappeared beneath the ocean by September 8, 2005. Some of the erosion may have occurred in other storms between 2001 and 2005, but Katrina is probably responsible for much of the damage. The ghost shores of the island are faintly visible under the water as a lighter shade of blue. West Ship Island, which hosts a civil war fort and a historic lighthouse, and Cat Island have also shrunk slightly. The southern tip of Cat Island is missing and the pointed tips of Ship Island have been rounded out. The section of the northwestern shore that holds the lighthouse and fort seems to be unchanged. East and West Ship Islands are no strangers to the type of erosion Katrina inflicted on them. The islands had been a single island until Hurricane Camille cleft it in two in 1969. In general, barrier islands are constantly changing, their shorelines building and eroding at remarkable speed, with dramatic change occurring routinely when powerful storms strike. In competition with nature, humans also have a large impact on barrier islands. Such islands are popular vacation spots. Construction can interfere with beach building and can degrade the vegetation that anchors dunes on the islands. Of the barrier islands along the U.S. coast, East Ship Island is one of the few that remains in its natural state, unchanged by population. To preserve the islands, Congress added them to Gulf Islands National Seashore [ http://www.nps.gov/guis/extended/MIS/MNature/Islands.htm ], the United States' largest national seashore, under the National Park Service. Cat Island forms the western boundary of the park, which consists of a string of islands along the Mississippi and Florida coasts, including East and West Ship Island. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
|
Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
A fringe of barrier islands line the coast of Mississippi, protecting the mainland from the pounding waves of most ocean storms, but the islands could not shelter the mainland from Hurricane Katrina's exceptionally powerful storm surge. The battering waves ate away at the islands, permanently altering their shape. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of East and West Ship Islands and Cat Island on September 8, 2005. The lower image is made up of two difference ASTER scenes. The scene on the left was acquired on June 4, 2005, while the scene on the right was taken on April 22, 2001. A diagonal line where the ocean changes color indicates the division between the two images. The most dramatic change can be seen in East Ship Island. Compared to April 2001, most of East Ship Island has disappeared beneath the ocean by September 8, 2005. Some of the erosion may have occurred in other storms between 2001 and 2005, but Katrina is probably responsible for much of the damage. The ghost shores of the island are faintly visible under the water as a lighter shade of blue. West Ship Island, which hosts a civil war fort and a historic lighthouse, and Cat Island have also shrunk slightly. The southern tip of Cat Island is missing and the pointed tips of Ship Island have been rounded out. The section of the northwestern shore that holds the lighthouse and fort seems to be unchanged. East and West Ship Islands are no strangers to the type of erosion Katrina inflicted on them. The islands had been a single island until Hurricane Camille cleft it in two in 1969. In general, barrier islands are constantly changing, their shorelines building and eroding at remarkable speed, with dramatic change occurring routinely when powerful storms strike. In competition with nature, humans also have a large impact on barrier islands. Such islands are popular vacation spots. Construction can interfere with beach building and can degrade the vegetation that anchors dunes on the islands. Of the barrier islands along the U.S. coast, East Ship Island is one of the few that remains in its natural state, unchanged by population. To preserve the islands, Congress added them to Gulf Islands National Seashore [ http://www.nps.gov/guis/extended/MIS/MNature/Islands.htm ], the United States' largest national seashore, under the National Park Service. Cat Island forms the western boundary of the park, which consists of a string of islands along the Mississippi and Florida coasts, including East and West Ship Island. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
|
Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Dauphin Island guards the mouth of Mobile Bay, Alabama, from the open waters of the Gulf of Mexico. Though not directly under the eye of the storm, the island was blasted with a powerful storm surge when Hurricane Katrina came ashore on August 29, 2005. When the storm passed, Dauphin Island had been divided in two. On September 10, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of the permanently altered island. A large inlet has been cut across the island in the same spot that a much smaller inlet existed before the storm. The western tip of the island has also been washed away, though no other changes are obvious. Miraculously, the thin causeway that connects the island to the mainland appears to be intact. In these images, vegetation is red while sand is a brilliant white. Barrier islands are constantly changing with shorelines building and eroding at remarkable speed. The islands are also routinely shaped by powerful storms, sometimes dramatically breaking apart as Dauphin Island broke under Katrina's wrath. Barrier islands often absorb the brunt of a hurricane's storm surge, offering some protection to the mainland shore. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
|
Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Dauphin Island guards the mouth of Mobile Bay, Alabama, from the open waters of the Gulf of Mexico. Though not directly under the eye of the storm, the island was blasted with a powerful storm surge when Hurricane Katrina came ashore on August 29, 2005. When the storm passed, Dauphin Island had been divided in two. On September 10, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of the permanently altered island. A large inlet has been cut across the island in the same spot that a much smaller inlet existed before the storm. The western tip of the island has also been washed away, though no other changes are obvious. Miraculously, the thin causeway that connects the island to the mainland appears to be intact. In these images, vegetation is red while sand is a brilliant white. Barrier islands are constantly changing with shorelines building and eroding at remarkable speed. The islands are also routinely shaped by powerful storms, sometimes dramatically breaking apart as Dauphin Island broke under Katrina's wrath. Barrier islands often absorb the brunt of a hurricane's storm surge, offering some protection to the mainland shore. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Rita Floods U.S. G
…
| Title |
Hurricane Rita Floods U.S. Gulf Coast |
| Description |
The Neches River flows 670 kilometers (416 miles) through Texas before pouring into Sabine Lake and then the Gulf of Mexico. In its final few kilometers, the river passes through Beaumont, Texas, one of the largest oil refining regions in East Texas. The river is an important conduit from the oil refineries to the Gulf of Mexico and the world. Beaumont and the Neches River were also almost directly in Hurricane Rita's path when it came ashore on September 24, 2005. There are some obvious signs of damage in the top image, collected by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite on September 27, 2005. Several permanent structures had been built in the bulge in the river shown here. The structures, probably related to the region's oil industry, were tossed in Rita's strong winds, heavy rains, and battering waves. Their positions have shifted compared to their locations on April 18, 2001, lower image. Some of the structures are clearly broken, with sections missing. Along the shore, dark flood water surrounds a series of circular buildings. These ASTER images are shown in false color. Vegetation is red, and water is dark blue. The large images extend from Beaumont in the north to the Gulf of Mexico. Additional flooding is evident near the Gulf in the large images. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Rita Floods U.S. G
…
| Title |
Hurricane Rita Floods U.S. Gulf Coast |
| Description |
The Neches River flows 670 kilometers (416 miles) through Texas before pouring into Sabine Lake and then the Gulf of Mexico. In its final few kilometers, the river passes through Beaumont, Texas, one of the largest oil refining regions in East Texas. The river is an important conduit from the oil refineries to the Gulf of Mexico and the world. Beaumont and the Neches River were also almost directly in Hurricane Rita's path when it came ashore on September 24, 2005. There are some obvious signs of damage in the top image, collected by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite on September 27, 2005. Several permanent structures had been built in the bulge in the river shown here. The structures, probably related to the region's oil industry, were tossed in Rita's strong winds, heavy rains, and battering waves. Their positions have shifted compared to their locations on April 18, 2001, lower image. Some of the structures are clearly broken, with sections missing. Along the shore, dark flood water surrounds a series of circular buildings. These ASTER images are shown in false color. Vegetation is red, and water is dark blue. The large images extend from Beaumont in the north to the Gulf of Mexico. Additional flooding is evident near the Gulf in the large images. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Wilma
| Title |
Hurricane Wilma |
| Description |
(MISR) acquired this sequence of images and cloud-top height observations for Hurricane Wilma as it progressed across the Caribbean in October 2005. Each pair in the sequence has a photo-like view of the storm on the left and a matching color-coded image of cloud-top height on the right. Cloud-top heights range from 0 (purple) to 18 (red) kilometers altitude. Areas where cloud heights could not be determined are shown in dark gray. The pair on the left shows Wilma on Tuesday, October 18, when Hurricane watches were posted for Cuba and Mexico. The central pair shows the eye of Hurricane Wilma just hours before the storm began to cross the Yucatan Peninsula on Friday, October 21. At that time, Wilma was a powerful Category 4 Hurricane on the Saffir-Simpson scale, and had a minimum recorded central pressure of 930 millibars. Hurricane Wilma surged from tropical storm to Category 5 hurricane status in record time, but the storm slowed and weakened considerably after battering Mexico's Yucatan Peninsula and the Caribbean. The right-hand image pair displays the eastern edges of a weakened Wilma, when Wilma had been reduced to Category 2 status and was just starting to reach southern Florida on the morning of Sunday, October 23. Wilma gathered speed and strengthened on Sunday night, crossing Florida as a Category 3 storm on Monday, October 24. On the 18th, Wilma looked a bit ragged. Its eye is located at the center of the left edge, and its outer bands of clouds appear to be dominated by a rather loose collection of thunderstorms. In the photo-like images, these look like areas of "boiling clouds," and in the cloud-height image, these appear as orange blobs, sometimes topped with pinkish-red. On October 21 (center), when Wilma was a Category 4 storm, cloud-top height on the eastern side of the storm near the eye reached 18 kilometers in altitude, with lower heights on the western side. The image from the 23rd shows the eastern edge of Wilma as it approached Florida (upper right) and Cuba (center right). MISR has nine different cameras that view the Earth from a variety of angles. Shifts in the clouds' apparent position from one camera's perspective to another's allows MISR to measure the height of the cloud-tops. MISR scientists have programmed computers to compare the different views, identify features that appear to shift from view to view, and use that information to calculate cloud height automatically. The height fields pictured have not been corrected for the effects of cloud motion. Wind-corrected heights (which have higher accuracy but sparser spatial coverage) are within about 1 kilometer of the heights shown here. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously, viewing the entire globe between 82° North and 82° South latitude every nine days. Each image covers an area of about 380 kilometers by 1,830 kilometers. The data products were generated from a portion of the imagery acquired during Terra orbits, 31037, 31081 and 31110, and utilize data from within blocks 68-83 within World Reference System-2 paths 13, 16 and 18, respectively. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. Text by Clare Averill (Raytheon RIS/JPL) and Greg McFarquhar (University of Illinois)., Information on cloud-top heights at different stages in the life cycle of the rapidly intensifying Hurricane Wilma may prove useful for evaluating the ability of numerical weather models to predict the intensity changes of hurricanes. NASA's Multi-angle Imaging SpectroRadiometer [ http://www-misr.jpl.nasa.gov/ ] |
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Java Mud Volcano Continues t
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| Title |
Java Mud Volcano Continues to Grow |
| Description |
On the island of Java, a "mud volcano" has been spewing thousands of cubic meters of mud every day since late May 2006. According to BBC news, British geologists believe that oil and gas drilling ruptured pressurized limestone rock and enabled water and mud to reach the surface. The oil company and others have suggested that the event could be related to the May 27 earthquake near Yogyakarta. [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13629 ] Regardless of the cause, the volcano has become a major hazard, creating a huge mud lake that buried villages and agricultural land. These images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite show the progression of the mud flow from September 3, 2006, [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17389 ] (middle) to February 10, 2006 (top). The bottom image, acquired on March 11, 2005, shows how the area looked before the mud flow began. In these infrared-enhanced, "false-color" images, bare ground appears gray, water appears dark blue, and vegetation appears red. Robust vegetation appears bright red. Although clouds partially obscure the February 10 image, the mud flow's advance can still be detected. In this image, the mud flow has spread beyond the toll road toward the east. Areas of robust vegetation in this image are smaller, although that could be partially due to a difference in season. A scientific survey published in the Geological Society of America's February issue of GSA Today stated that the mud volcano could release between 7,000 and 150,000 cubic meters of mud every day for years. According to Reuters, there was concern that mud might pollute the water, damaging the area's shrimp industry. In an attempt to slow the mud flow, the Indonesian government has approved a plan to drop concrete balls linked by heavy chains into the mouth of the volcano, according to news reports. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Lake Oahe, Dakotas
| Title |
Lake Oahe, Dakotas |
| Description |
The Missouri River and its surrounding ecosystems are struggling in the tight fist of a 6-year drought. In North Dakota, 374-kilometer-long Lake Oahe, the nation's fourth largest reservoir, is so low that it has left the state. The long, thin reservoir extends upriver from the Oahe Dam on the Missouri from Pierre, South Dakota, to Bismarck, North Dakota. North of the state line, more than 100 kilometers of the lake that were formerly about 8 kilometers wide have reverted to a narrow river. The shrinking of the lake has left behind weedy mudflats and boat ramps stranded 2 kilometers from the water's edge. These images of Lake Oahe show the reservoir on April 4, 2005, (right) compared to the level on May 18, 2000 (left). The Missouri runs through the center of the images in a dark blue line. The image on the left was captured by NASA's Landsat 7 satellite, while the image on the right was captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. In both images, vegetation appears in shades of red, while bare or sparsely vegetated ground are in shades of green (May 18 image) or tan (April 4 image). The already-thin reservoir has shrunk dramatically in the four years between the images. Both images cover an area of 28.7 by 65.6 kilometers, and they are centered along the North and South Dakota border. The drought's list of effects is long and painful: shortage of drinking and irrigation water, reduction in hydroelectric capacity, decrease in tourism, reduction in shipping, threats to endangered wildlife. The cause is the continuing yearly shortage of snowpack in the Rocky Mountains in Montana, where the Missouri River has its headwaters. NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Landslide Lake in Tibet Floo
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| Title |
Landslide Lake in Tibet Floods India |
| Description |
Roughly a year after forming behind a landslide dam, the lake on the Pareechu River in Tibet began to drain on June 26, 2005. Water and mud gushed down the Pareechu River into the Sutlej, the major river that flows through India?s Himachal Pradesh state. Thousands were evacuated from the banks of the Sutlej, and though several bridges and buildings were damaged or destroyed, no injuries were reported in the flood, according to news reports. On July 2, 2005, the Advanced Spaceborne Thermal Emission and Reflection Radiometer, (ASTER [ http://asterweb.jpl.nasa.gov/ ]) on NASA?s Terra [ http://terra.nasa.gov/ ] satellite captured the top image of the shrinking lake. Both the lake and the river behind it have shrunk considerably since September 1, 2004, when the lower image was taken. A silvery sheen of mud or gravel seems to have replaced the dark blue water in the upper reaches of the river and lake. Below the lake, the river has grown where water is now pushing its way downstream. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team |
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Eruption of Colima Volcano
| Title |
Eruption of Colima Volcano |
| Description |
A series of explosive eruptions have thundered from the Colima Volcano, Mexico?s most active volcano. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of the Colima Volcano on June 3, 2005, just hours after two spectacular eruptions rumbled from the volcano. Two days later, on June 5, Colima experienced its strongest eruption in 20 years when it sent a dark column of ash more than five kilometers into the atmosphere at a rate of roughly 30 kilometers per hour, reports the Universidad de Colima?s Observatorio Vulcanologico [ http://www.ucol.mx/volcan/ ]. Colima also erupted on May 24 and May 30, and the ash from these and the June 2 and June 3 eruptions is clearly visible in the top image. A grey river of ash and rock flows down the west side of the peak, covering the vegetation that was visible on February 6, 2003, lower image. In these false-color images, the dense vegetation that surrounds the volcano is red. A light dusting of ash blankets the trees on the southeast side of the volcano, and fresh flows stream down all sides of the volcano. Because of its resemblance to the cloud in the upper right corner of the image, the cloud that rests over the summit of the volcano is probably a regular cloud, though it could also be a plume of steam. NASA image created by Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov ] |
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Eruption of Colima Volcano
| Title |
Eruption of Colima Volcano |
| Description |
A series of explosive eruptions have thundered from the Colima Volcano, Mexico?s most active volcano. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of the Colima Volcano on June 3, 2005, just hours after two spectacular eruptions rumbled from the volcano. Two days later, on June 5, Colima experienced its strongest eruption in 20 years when it sent a dark column of ash more than five kilometers into the atmosphere at a rate of roughly 30 kilometers per hour, reports the Universidad de Colima?s Observatorio Vulcanologico [ http://www.ucol.mx/volcan/ ]. Colima also erupted on May 24 and May 30, and the ash from these and the June 2 and June 3 eruptions is clearly visible in the top image. A grey river of ash and rock flows down the west side of the peak, covering the vegetation that was visible on February 6, 2003, lower image. In these false-color images, the dense vegetation that surrounds the volcano is red. A light dusting of ash blankets the trees on the southeast side of the volcano, and fresh flows stream down all sides of the volcano. Because of its resemblance to the cloud in the upper right corner of the image, the cloud that rests over the summit of the volcano is probably a regular cloud, though it could also be a plume of steam. NASA image created by Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov ] |
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Eruption of Colima Volcano
| Title |
Eruption of Colima Volcano |
| Description |
Recurring eruptions of the Colima Volcanco have left visible changes on the local landscape since February 2003. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov/ ] flying on NASA?s Terra [ http://terra.nasa.gov/ ] satellite, captured images of the Colima Volcano on June 21, 2005 (top), June 3, 2005 (middle), and February 6, 2003 (bottom). In these false-color images, vegetation appears in red, and rock and ash flows appear in gray. Between June 3 and June 21, eruptions sent a silvery gray stream of ash and rock down the east side of the mountain and dusted the forest with ash. In contrast to February 2003, the area covered by rock and ash has expanded in both 2005 images. The white clouds seen in both June images may be steam from the volcano but are more likely clouds passing overhead. Recorded eruptions of the Colima Volcano date back to the 16th century, and a major eruption in 1913 destroyed the volcano?s summit. Volcanoes pose multiple hazards [ http://pubs.usgs.gov/fs/fs002-97/ ], many of which have been felt by local residents. According to news reports, repeated eruptions since early May 2005 have prompted evacuations of nearby communities. Ash fall has covered local highways, forced a temporary closure of Colima International Airport, and even killed some local livestock. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Eruption of Colima Volcano
| Title |
Eruption of Colima Volcano |
| Description |
Recurring eruptions of the Colima Volcanco have left visible changes on the local landscape since February 2003. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov/ ] flying on NASA?s Terra [ http://terra.nasa.gov/ ] satellite, captured images of the Colima Volcano on June 21, 2005 (top), June 3, 2005 (middle), and February 6, 2003 (bottom). In these false-color images, vegetation appears in red, and rock and ash flows appear in gray. Between June 3 and June 21, eruptions sent a silvery gray stream of ash and rock down the east side of the mountain and dusted the forest with ash. In contrast to February 2003, the area covered by rock and ash has expanded in both 2005 images. The white clouds seen in both June images may be steam from the volcano but are more likely clouds passing overhead. Recorded eruptions of the Colima Volcano date back to the 16th century, and a major eruption in 1913 destroyed the volcano?s summit. Volcanoes pose multiple hazards [ http://pubs.usgs.gov/fs/fs002-97/ ], many of which have been felt by local residents. According to news reports, repeated eruptions since early May 2005 have prompted evacuations of nearby communities. Ash fall has covered local highways, forced a temporary closure of Colima International Airport, and even killed some local livestock. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Eruption of Colima Volcano
| Title |
Eruption of Colima Volcano |
| Description |
Recurring eruptions of the Colima Volcanco have left visible changes on the local landscape since February 2003. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov/ ] flying on NASA?s Terra [ http://terra.nasa.gov/ ] satellite, captured images of the Colima Volcano on June 21, 2005 (top), June 3, 2005 (middle), and February 6, 2003 (bottom). In these false-color images, vegetation appears in red, and rock and ash flows appear in gray. Between June 3 and June 21, eruptions sent a silvery gray stream of ash and rock down the east side of the mountain and dusted the forest with ash. In contrast to February 2003, the area covered by rock and ash has expanded in both 2005 images. The white clouds seen in both June images may be steam from the volcano but are more likely clouds passing overhead. Recorded eruptions of the Colima Volcano date back to the 16th century, and a major eruption in 1913 destroyed the volcano?s summit. Volcanoes pose multiple hazards [ http://pubs.usgs.gov/fs/fs002-97/ ], many of which have been felt by local residents. According to news reports, repeated eruptions since early May 2005 have prompted evacuations of nearby communities. Ash fall has covered local highways, forced a temporary closure of Colima International Airport, and even killed some local livestock. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Eruption of Klyuchevskaya Vo
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| Title |
Eruption of Klyuchevskaya Volcano |
| Description |
The rising sun bathes the eastern half of Russia's Kamchatka Peninsula with light, casting long shadows in the west. The shadows highlight the plume of ash that continues to rise from the Klyuchevskaya Volcano. The largest and most active volcano on the peninsula, Klyuchevskaya has erupted regularly since its first recorded eruption in 1697. Its most recent activity began in mid-January 2005, and has not abated. Dark ash from the ongoing eruption dusts the snow in this image, acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite on March 12, 2005. In addition to the large plume of ash visible in this image, the ongoing eruption has sent molten lava down the volcano's northeast slope, where it is melting the Ehrman glacier. This activity may be responsible for the rivers of water that can be seen in the snow near the northeast base of the volcano. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
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Eruption of Santa Ana (Ilama
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| Title |
Eruption of Santa Ana (Ilamatepec) Volcano |
| Description |
Between October 5 and October 11, 2005, the Santa Ana (Ilamatepec) Volcano produced a series of eruptions consisting of small explosions, gas emissions, and low or moderate seismic activity. Local weather conditions prevented researchers from making ground- or satellite-based inspections of the volcano. An aerial inspection on October 11, however, showed no changes in the volcano's crater. These false-color images were made from data collected by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite. The top image shows Santa Ana during its eruptive period in early October 2005, with features not visible in the earlier image: a new lava flow, and a mudslide. The blue-green crater lake in the center of the volcano is noticably smaller. News reports from early October 2005 discussed a flood of boiling mud and water, and molten rocks, some the size of small automobiles. Historical eruptions of Santa Ana include small-to-moderate explosive eruptions. The volcano's prehistoric activity was more dramatic, collapse during the late Pleistocene or early Holocene caused an avalanche of debris that stormed all the way into the Pacific and formed the Acajutla Peninsula. After the eruption of October 5-11, 2005, the Servicio Nacional de Estudios Territoriales (SNET) warned that Santa Ana's burst of activity might not be over. Authorities maintained a red alert (the highest level) for a 5-kilometer radius around Santa Ana's central crater. For more information about Santa Ana, please visit the Smithsonian Institution's Global Volcanism Program [ http://www.volcano.si.edu/index.cfm ]. NASA image by Jesse Allen based on data provided by Timothy Gubbels and Asad Ullah, SSAI, and the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Eruption of Santa Ana (Ilama
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| Title |
Eruption of Santa Ana (Ilamatepec) Volcano |
| Description |
Between October 5 and October 11, 2005, the Santa Ana (Ilamatepec) Volcano produced a series of eruptions consisting of small explosions, gas emissions, and low or moderate seismic activity. Local weather conditions prevented researchers from making ground- or satellite-based inspections of the volcano. An aerial inspection on October 11, however, showed no changes in the volcano's crater. These false-color images were made from data collected by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite. The top image shows Santa Ana during its eruptive period in early October 2005, with features not visible in the earlier image: a new lava flow, and a mudslide. The blue-green crater lake in the center of the volcano is noticably smaller. News reports from early October 2005 discussed a flood of boiling mud and water, and molten rocks, some the size of small automobiles. Historical eruptions of Santa Ana include small-to-moderate explosive eruptions. The volcano's prehistoric activity was more dramatic, collapse during the late Pleistocene or early Holocene caused an avalanche of debris that stormed all the way into the Pacific and formed the Acajutla Peninsula. After the eruption of October 5-11, 2005, the Servicio Nacional de Estudios Territoriales (SNET) warned that Santa Ana's burst of activity might not be over. Authorities maintained a red alert (the highest level) for a 5-kilometer radius around Santa Ana's central crater. For more information about Santa Ana, please visit the Smithsonian Institution's Global Volcanism Program [ http://www.volcano.si.edu/index.cfm ]. NASA image by Jesse Allen based on data provided by Timothy Gubbels and Asad Ullah, SSAI, and the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Mount St. Helens
| Title |
Mount St. Helens |
| Description |
Several days after the most recent eruption of Mount St. Helens, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA?s Terra satellite captured this cloud-free shot of the volcano. This image from March 15, 2005, is a combination of ASTER?s observations in near-infrared, red, and green wavelengths (ASTER bands 3, 2, & 1). Snow appears white, bare ground is grey to brown, while vegetation, such as conifererous forests on the mountain slopes, appears red. The image reveals that the March 8 eruption did not disturb the new lava dome, as it is still intact near the southern rim of the crater. The lava dome continues to grow, made of old rock being pushed up by magma from underneath and of new rock formed from molten lava. The new rock is building the lava dome along what scientists are calling the ?whaleback.? ASTER observed the spine of the whaleback in the shortwave-infrared bands (inset), which show bright hotspots in a line down the center of the dome. As this image reveals, hot rock continues to push to the surface, adding to the bulk of the lava dome. The dome has expanded so that it now impinges on the south crater rim. The crater rim is the large circular feature in the center of the image, and the southern rim casts a very dark shadow onto the floor of the crater. The sharp ridge that marks the crater?s boundary is broken by a large gap in the northeast. During the eruption of Mount St. Helens in May 1980, this part of the crater rim and a large section of the northern flank exploded and collapsed in a massive landslide, which was followed by a devastating flow of volcanic material, trees, melted snow, and mud. NASA image created by Jesse Allen, Earth Observatory, using ASTER data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
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Mount St. Helens
| Title |
Mount St. Helens |
| Description |
Believe it or not, Mount St. Helens was an erupting volcano when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) acquired this image on December 12, 2005. It may not be spouting ash and steam, but Mount St. Helens is steadily pushing a column of rock into its crater. Throughout 2005, the dome in the volcano's crater grew by an average of two cubic meters per second as magma pushed its way steadily up. In this image, snow and shadow mask the growing dome, which is on the southeast side of the crater. There are several types of volcanic eruptions [ http://pubs.usgs.gov/gip/volc/eruptions.html ] ranging from violent explosions to oozing lava, and Mount St. Helens has demonstrated many of them. In 1980, the volcano erupted violently, sending up a cloud of ash and volcanic gas and blasting pyroclastic flowsfast-moving clouds of rock fragments, ash, and gasesdown the mountain. The most recent eruption [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=12489 ] started with a swarm of earthquakes on September 23, 2004. By October 1, the volcano has breathed out a plume of ash and steam, and then settled into its dome-building eruption on October 11, 2004. Fourteen months later, the dome-building eruption continued, punctuated by small earthquakes that shake the mountain every minute and a half as magma rises in the dome. Mount St. Helens is the youngest and most frequently active of all of the volcanoes in the Cascade Range of the northwestern United States. The Cascades Volcano Observatory [ http://vulcan.wr.usgs.gov/Volcanoes/MSH/framework.html ] provides daily updates and photos of the eruption. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of the NASA/GSFC/METI/ERSDAC/JAROS and U.S./Japan ASTER Science Team |
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New Measurements of Arctic O
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| Title |
New Measurements of Arctic Ozone |
| Description |
The winter of 2004-2005 saw the second highest chemical ozone destruction ever observed over the Arctic. Polar ozone is destoyed when chlorine, cold temperatures, and sunlight mix in the atmosphere 8-50 kilometers above the Earth's surface. Since ozone shields the Earth from ultraviolet light, the high-energy light that causes sunburns and is associated with skin cancers, low ozone levels could threaten human health. Ultraviolet levels remained near normal through the winter, however, because unusual weather conditions brought ozone from the Earth's ozone-rich mid-latitudes to the pole to fill in the gaps left by the extreme ozone depletion. These images show the fluctuations in ozone during the Arctic winter of 2005. The top two images show the average total column ozone over the Arctic during the months of January and March, 2005, and the lower image shows total column ozone on a single day, March 11, 2005. The images are based on data collected by the Ozone Monitoring Instrument [ http://www.knmi.nl/omi/publ-en/news/index.html ] (OMI) aboard NASA's Aura [ http://aura.gsfc.nasa.gov/ ] satellite. During this time period, the Microwave Limb Sounder, another instrument on the Aura satellite, measured 50 percent ozone loss, the second-highest level ever observed behind the 60 percent loss measured in 1999-2000. Despite this, the lowest total column ozone values in polar regions are slightly higher in March than in January, on average, as evidenced by the broad splashes of red that represent high ozone levels. Stratospheric winds carried the ozone north into the Arctic, compensating for the significant chemical loss, so that no blue or purple holes representing low ozone levels appear in the March image. Black circles over the North pole show where OMI did not collect data. On a single day, March 11, 2005, ozone was distributed far more unevenly, with dark red, almost black areas of high ozone over the Aleutian Islands, Asia, and Europe, and a pale blue thin spot over Iceland and Greenland. This reveals that even though ozone values appeared to be near normal on average throughout March, some regions experienced much lower ozone levelsand therefore, a greater exposure to UV lighton an individual day. For more information and images, see "NASA Spacecraft Measures Unusual 2005 Arctic Ozone Conditions" [ http://www.nasa.gov/vision/earth/lookingatearth/aura-060205.html ] on the NASA portal. Image courtesy NASA/JPL/Agency for Aerospace Programs (Netherlands)/Finnish Meteorological Institute |
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North Reef Island, Andaman S
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| Title |
North Reef Island, Andaman Sea |
| Description |
On December 26, 2004, one of the largest earthquakes in recorded history struck offshore of the island of Sumatra, Indonesia. The ocean floor heaved in some places and sank in others, creating catastrophic tsunamis that raced across the Indian Ocean. Hundreds of thousands of people died as the waves struck coastlines from Thailand to Sri Lanka to Somalia. In addition to tsunami damage, satellite images of reefs, islands, and coastlines identified signs of permanent elevation changesinking or upliftalong the fault between the Indo-Australia and Burma plates. [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=12640 ] In places such as North Reef Island, shown in this pair of images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite, the quake lifted the reefs permanently out of the water. The images use visible and infrared light detected by ASTER to make different land surfaces stand out clearly from one another: water is blue, vegetation is red, coral or bare sand appears white. In the "before" image, from December 2, 2004, the submerged reef creates a bright blue glow around the island. In the "after" image, from February 4, 2005, the white coral stands completely up out of the water. It is even tinged with red, which suggests the exposed coral had died, and algae had colonized it. In the weeks and months after the earthquake, satellite images provided broad coverage of an area where ground-based observations were initially very limited. A team of scientists led by Caltech Ph.D. geology student Aron Meltzner discovered changes in elevation along nearly 1,600 kilometers (994 miles) of the tectonic plate boundary. The images revealed that the earthquake rupture extended 100 kilometers (62 miles) farther north than estimates based on seismic and Global Positioning System (GPS) data suggested. The feature article Rise and Fall: Satellites Reveal Full Length of Tsunami-Generating Earthquake [ http://earthobservatory.nasa.gov/Study/Aceh/aceh.html ] describes how scientists used satellite images to map the length of the earthquake rupture zone. The article includes additional satellite and ground-based images of elevation changes resulting from the 2004 Aceh-Andaman earthquake. NASA images created by Jesse Allen, Earth Observatory, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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North Reef Island, Andaman S
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| Title |
North Reef Island, Andaman Sea |
| Description |
On December 26, 2004, one of the largest earthquakes in recorded history struck offshore of the island of Sumatra, Indonesia. The ocean floor heaved in some places and sank in others, creating catastrophic tsunamis that raced across the Indian Ocean. Hundreds of thousands of people died as the waves struck coastlines from Thailand to Sri Lanka to Somalia. In addition to tsunami damage, satellite images of reefs, islands, and coastlines identified signs of permanent elevation changesinking or upliftalong the fault between the Indo-Australia and Burma plates. [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=12640 ] In places such as North Reef Island, shown in this pair of images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite, the quake lifted the reefs permanently out of the water. The images use visible and infrared light detected by ASTER to make different land surfaces stand out clearly from one another: water is blue, vegetation is red, coral or bare sand appears white. In the "before" image, from December 2, 2004, the submerged reef creates a bright blue glow around the island. In the "after" image, from February 4, 2005, the white coral stands completely up out of the water. It is even tinged with red, which suggests the exposed coral had died, and algae had colonized it. In the weeks and months after the earthquake, satellite images provided broad coverage of an area where ground-based observations were initially very limited. A team of scientists led by Caltech Ph.D. geology student Aron Meltzner discovered changes in elevation along nearly 1,600 kilometers (994 miles) of the tectonic plate boundary. The images revealed that the earthquake rupture extended 100 kilometers (62 miles) farther north than estimates based on seismic and Global Positioning System (GPS) data suggested. The feature article Rise and Fall: Satellites Reveal Full Length of Tsunami-Generating Earthquake [ http://earthobservatory.nasa.gov/Study/Aceh/aceh.html ] describes how scientists used satellite images to map the length of the earthquake rupture zone. The article includes additional satellite and ground-based images of elevation changes resulting from the 2004 Aceh-Andaman earthquake. NASA images created by Jesse Allen, Earth Observatory, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Rice Cultivation in Northwes
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| Title |
Rice Cultivation in Northwest Italy |
| Description |
The lowlands of Lombardy and Piedmont in northwest Italy are some of the most highly developed irrigation areas in the world. Irrigated lands cover at least 160,000 acres in this part of Italy, where rice is the most important crop. These views of the region were acquired on May 8, 2005, by NASA's Multi-angle Imaging SpectroRadiometer (MISR). The multiple viewing angles provided by MISR's nine cameras make it possible to tell wet surfaces, including flooded lands, from other surfaces, and they also make cities easy to locate. The left-hand image is a natural-color view acquired by MISR's downward-looking (nadir) camera, and the right-hand image is a combination of red band data from MISR's 60-degree-backward-, nadir, and 60-degree-forward-viewing cameras. (Red band is what scientists call the "channel" on the sensor that detects red light.) Color changes indicate surface texture, which is influenced by terrain, vegetation structure, soil type, and surface wetness. Wet surfaces or areas with standing water appear in blue or purple-blue hues. The purple-blue areas that dominate the center-left part of the image are part of the extensive irrigation network that exists throughout the plains and meadows of the region. Cities with tall buildings appear in red-orange hues. In this type of image, the city of Milan is the most obvious. The small orange area in the center of the purple inundated area indicates the location of Vercelli, and the larger city of Milan is the orange area to the northeast, on the other side of the Ticino River. To a lesser extent, the cities of Novara, Pavia, Galliate, Mortara, and Vigevano are also identifiable by their orange hues. MISR can tell various surface features like cities or irrigated areas apart because of the way surfaces reflect light. A smooth water surface tends to reflect sunlight away from the Sun. This effect is most apparent when a satellite views the surface with the Sun in front of the camera. Similarly, rough surfaces tend to reflect light back towards the Sun, and this "backward scattering" is most obvious when a satellites views a surface with the Sun behind the camera. Clouds present over the high country to the west of the Lago Maggiore (upper left corner) and along the coast of the Golfo di Genova (bottom) appear in a different spot for each view angle, creating a rainbow-like appearance. Mountains also have a "wavy" look in the multi-angle combination because, like clouds, their height above the surface makes them appear in a different spot in each camera's view angle. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously, viewing the entire globe between 82 degrees North and 82 degrees South latitude every nine days. This image covers an area of about 131 kilometers by 191 kilometers. These data products were generated from a portion of the imagery acquired during Terra orbit 28660 and utilize data from block 54 within World Reference System-2 path 193. MISR was, built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is managed for NASA by the California Institute of Technology. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. [ http://www-misr.jpl.nasa.gov/ ] Text by Clare Averill (Raytheon ITSS/JPL) |
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San Marino Enclave in Italy
| Title |
San Marino Enclave in Italy |
| Description |
With an area of just 61 square kilometers (23.5 square miles), Serenissima Repubblica di San Marino (Italian for "Most Serene Republic of San Marino") is the third-littlest country in Europe, behind Monaco and Vatican City. With a population of just over 28,000 as of January 2005, it is also one of the least populous nations in the world. Located in the northern part of the Italian Peninsula, near the Adriatic Sea, this tiny nation is surrounded by Italy. On June 7, 2001, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite took this picture of San Marino and the part of Italy immediately surrounding it. The image shows a combination of vegetation (bright green), and buildings, pavement, and bare rock (blue-gray to white). Purplish-gray polygons are probably fallow agricultural land. Overhead, fluffy white clouds cast their charcoal-colored shadows over the land surface. The Apennine Mountains give the region a rough terrain, and the limestone Monte Titano dominates the area, with a fort perched on each of the mountain's three summits. According to legend, San Marino [ http://encarta.msn.com/encyclopedia_761565721/San_Marino.html ] is the world's oldest surviving republic, dating back to 301. The original city sits atop Monte Titano. Today, however, development has spread throughout the republic, evidenced by the many areas of blue-gray and the meandering roads. Tourism has brought prosperity to this small republic, but historically, its rugged terrain and lack of wealth may have helped it escape the unwanted attention of potential invaders. NASA image created by Jesse Allen, using data provided courtesy of NASA/GSFC/MITI/ERSDAC/JAROS, and the U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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