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Sun and Terra of Goddard Space Flight Center (GSFC)
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NASA's Orbiting Earth Observ
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| Title |
NASA's Orbiting Earth Observing Fleet (includes Aura) |
| Abstract |
NASA's Earth Observing fleet of vehicles constitutes a major milestone in the history of Earth science, facilitating the kinds of wide scale and synergistic research endeavors that until the last decade have been impossible to even consider. Many of the techniques being employed around Earth are a direct offshoot of technological and scientific techniques developed on missions to other worlds. NASA's continued commitment to primary research about our home remains a top priority not only to the agency, but to the nation, and the world as a whole. This visualization shows the spacecraft in NASA's Earth Observing fleet. The relative altitudes, speeds, and sun position are correct for 12-01-2003 starting at 5:00 UTC. Aura was added as it would appear in orbit (if it were in orbit at this time). |
| Completed |
2004-05-13 |
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A Summer View of Russia's Le
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| Title |
A Summer View of Russia's Lena Delta and Olenek River |
| Description |
These views of the Russian Arctic were acquired by NASA's Multi-angle Imaging SpectroRadiometer (MISR) instrument on July 11, 2004. The brief arctic summer had transformed the frozen tundra and the thousands of lakes, channels, and rivers of the Lena Delta into a fertile wetland, and the usual blanket of thick snow had melted from the vast plains and taiga forests. The images show an area in the northern part of the Sakha Republic in eastern Siberia. The Olenek River wends northeast from the bottom of the images to the upper left, and the delta through which the mighty Lena River empties into the Laptev Sea dominate the top portions of the images. Creating accurate maps of vegetation structure is essential for understanding the seasonal exchanges of energy and water at the Earth's surface and for preserving biodiversity. The left-hand image is a natural-color image from MISR's nadir (vertical-viewing) camera, in which the rivers appear murky due to sediment, and photosynthetically active vegetation appears green. The center image is also from MISR's nadir camera, but is a false-color view in which the predominant red color is due to the brightness of vegetation at near-infrared wavelengths. Apart from the Lena Delta, the most photosynthetically active regions are within the lower half of the image and throughout the great stretch of land that curves across the Olenek River.  The relatively barren ranges of the Volyoi Mountains appear as the pale tan-colored area to the right of image center. The right-hand image is a multiangle, false-color view made from the red band data of the 60-degree-backward, nadir, and 60-degree-forward cameras, displayed as red, green and blue, respectively. Water appears blue in this image because sun glint makes smooth, wet surfaces look brighter at the forward camera's view angle. Much of the landscape and many low clouds appear purple because these surfaces are both forward and backward scattering, and clouds that are further from the surface appear in a different spot for each view angle, creating a rainbow-like appearance. The highly vegetated region in the natural-color nadir image exhibits a faint greenish hue in the multi-angle composite. This subtle effect suggests that the nadir camera is observing more of the brighter, underlying surface than the oblique cameras, providing information about the distribution and density of trees and shrubs in this area. The Multiangle Imaging SpectroRadiometer observes the daylit Earth continuously, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. The MISR Browse Image Viewer [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://eosweb.larc.nasa.gov/MISRBR/ ], provides access to low-resolution true-color versions of these images. These data products were generated from a portion of the imagery acquired during Terra orbit 24273. The panels cover an area of about 230 kilometers x 420 kilometers, and utilize data from blocks 30 to 34 within World Reference System-2 path 134. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. [ http://www-misr.jpl.nasa.gov/ ] Text by Clare Averill (Raytheon/JPL). |
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Floods in India and Banglade
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| Title |
Floods in India and Bangladesh |
| Description |
Intense monsoon rains beginning in mid-June combined with melting snow running out of the Himalaya Mountains to trigger extensive flooding across Bangladesh and northeastern India at the end of June and beginning of July 2004. This Moderate Resolution Imaging Spectroradiometer [ http://modis.gsfc.nasa.gov ] (MODIS) image, acquired on June 28 by the Terra [ http://terra.nasa.gov/ ] satellite, shows just how widespread the floods are. The image includes an area that is about 2000 kilometers wide, and dark blue water, not present in an image taken on May 8 during the dry season, covers much of the scene. In this false-color image pair, water is dark blue, vegetation is bright green, and clouds are light blue. Bare earth is tan. In the flood image, the sun is reflecting off the surface of the water, creating a bright white patch near the center of the image. As of July 10, 55 people had died in the floods in northeastern India, and hundreds of thousands more have been affected. In Bangladesh, high waters stranded nearly half a million people, according to news reports. NASA image courtesy Jesse Allen, based on data from the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at Goddard Space Flight Center. |
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Floods in India and Banglade
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| Title |
Floods in India and Bangladesh |
| Description |
Intense monsoon rains beginning in mid-June combined with melting snow running out of the Himalaya Mountains to trigger extensive flooding across Bangladesh and northeastern India at the end of June and beginning of July 2004. This Moderate Resolution Imaging Spectroradiometer [ http://modis.gsfc.nasa.gov ] (MODIS) image, acquired on June 28 by the Terra [ http://terra.nasa.gov/ ] satellite, shows just how widespread the floods are. The image includes an area that is about 2000 kilometers wide, and dark blue water, not present in an image taken on May 8 during the dry season, covers much of the scene. In this false-color image pair, water is dark blue, vegetation is bright green, and clouds are light blue. Bare earth is tan. In the flood image, the sun is reflecting off the surface of the water, creating a bright white patch near the center of the image. As of July 10, 55 people had died in the floods in northeastern India, and hundreds of thousands more have been affected. In Bangladesh, high waters stranded nearly half a million people, according to news reports. NASA image courtesy Jesse Allen, based on data from the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at Goddard Space Flight Center. |
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Forest Fire Smoke Surroundin
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| Title |
Forest Fire Smoke Surrounding Mt. McKinley |
| Description |
This view of Mt McKinley (Denali)—the highest point in North America (6,194 meters, 20,230 feet)—looks as if it were taken from an aircraft. In fact, an astronaut onboard the International Space Station took advantage of cloud-free skies and a powerful 800-millimeter lens to photograph this peak while the spacecraft was over the Gulf of Alaska, 800 miles to the south of the mountain. The powerful lenses are difficult to use, requiring motion compensation by the astronaut, so these kinds of detailed images of horizon detail are seldom taken. The rising sun casts long shadows across the Kahiltna Glacier that angles down from Denali (left). In addition to the blueness inherent in all images taken at great distance (the atmosphere scatters blue light more than it does other colors), this image also shows unusually dense atmospheric haze at lower altitudes: all the valleys in the foreground appear murky. The explanation is dramatically portrayed in a Moderate Resolution Imaging Spectroradiometer (MODIS) image taken on the same day, Sunday, August 14, from the Terra satellite. On that day, an enormous smoke pall hung over central Alaska, all the major mountain ranges protruded above the smoke layer, which was held close to the surface by high atmospheric pressure. The smoke came from more than 100 forest fires burning in the summer heat of Alaska. The MODIS image shows that the smoke on August 14 was far thicker to the north of the Alaska Range where Denali is. The Space Station image shows this denser smoke settled between the Alaska Range and the distant horizon of the Kuskokwim Mountains, 80 miles to the north. Astronaut photograph ISS011-E-11806 [ http://eol.jsc.nasa.gov/scripts/sseop/photo.pl?mission=ISS011&roll=E&frame=11806 ] was acquired August 14, 2005, with a Kodak 760C digital camera fitted with an 800 mm lens, and is provided by the ISS Crew Earth Observations experiment and the Image Science & Analysis Group, Johnson Space Center. The International Space Station Program [ http://spaceflight.nasa.gov/home/index.html ] supports the laboratory to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. [ http://eol.jsc.nasa.gov/ ] |
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Chilean Lake Disappears
| Title |
Chilean Lake Disappears |
| Description |
In May 2007, the Chilean Forestry Corporation discovered that a lake in the Southern Patagonia Icefield in the Chilean Andes had disappeared. Chilean glaciologists had observed the 20,000-square-meter (roughly 215,000-squre-foot) lake, which was located between the tongues of the Glaciar Témpanos and Glaciar Bernardo, in March. (Glaciar is Spanish for "glacier.") Two months later, nothing remained except a 30-meter- (100-foot-) deep crater and some stranded ice that had once floated on the water's surface. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite captured the top image on June 23, 2007, showing a crater that the lake had occupied. In this image, the crater lies mostly in shadow, due to the low angle of the Sun during the Southern Hemisphere's winter. Despite the shadows, contour lines around the lake show where the ground level is lower than the surroundings. East of the drained lake, water still appears near the tongue of Glaciar Bernardo. In this image, made from a combination of visible and infrared light detected by ASTER, red indicates vegetation, and patches of red peek through the snow cover. ASTER acquired the bottom image on April 4, 2007, when the lake was still in place. In this image—acquired in the Chilean autumn—both the lake and a nearby tributary appear full, shown by the blue-tinted water. Vibrant red, lush vegetation covers the landscape. Although the sudden draining of a lake is rare, it is not unheard of. One explanation that scientists proposed was an earthquake in the region that measured 6.2 on the Richter scale. Earthquakes can open up fissures in the rock, giving water an escape route. Another explanation was more prosaic: melting. Blocks of ice dam many glacial lakes, and when the ice melts, the lake can drain away. Sometimes a lake can drain in a rapid deluge, known as a glacial lake outburst flood. After flying over the region in late June 2007, scientists from Centro de Estudios Cientificos (CECS) and the Chilean Navy concluded that the likely culprit for the lake's disappearance was such a flood. Dr. Andrés Rivera, a glaciologist from CECS, described the flow. "The lake's water flowed to the north along the western margin of Glaciar Bernardo and into a big hole, [ http://www.imaginaccion.cl/cecs.html ] where the water went down into a glacier tunnel in the direction to Bernardo Fjord," he said. Bernardo Fjord empties into the Pacific Ocean. You can also download a 15-meter-resolution KMZ file of the region around the "missing" lake [ http://earthobservatory.nasa.gov/Newsroom/NewImages/Images/lagotempanos_ast_2007174.kmz ], including both April 4 and June 23, 2007, images, suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
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Chilean Lake Disappears
| Title |
Chilean Lake Disappears |
| Description |
In May 2007, the Chilean Forestry Corporation discovered that a lake in the Southern Patagonia Icefield in the Chilean Andes had disappeared. Chilean glaciologists had observed the 20,000-square-meter (roughly 215,000-squre-foot) lake, which was located between the tongues of the Glaciar Témpanos and Glaciar Bernardo, in March. (Glaciar is Spanish for "glacier.") Two months later, nothing remained except a 30-meter- (100-foot-) deep crater and some stranded ice that had once floated on the water's surface. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite captured the top image on June 23, 2007, showing a crater that the lake had occupied. In this image, the crater lies mostly in shadow, due to the low angle of the Sun during the Southern Hemisphere's winter. Despite the shadows, contour lines around the lake show where the ground level is lower than the surroundings. East of the drained lake, water still appears near the tongue of Glaciar Bernardo. In this image, made from a combination of visible and infrared light detected by ASTER, red indicates vegetation, and patches of red peek through the snow cover. ASTER acquired the bottom image on April 4, 2007, when the lake was still in place. In this image—acquired in the Chilean autumn—both the lake and a nearby tributary appear full, shown by the blue-tinted water. Vibrant red, lush vegetation covers the landscape. Although the sudden draining of a lake is rare, it is not unheard of. One explanation that scientists proposed was an earthquake in the region that measured 6.2 on the Richter scale. Earthquakes can open up fissures in the rock, giving water an escape route. Another explanation was more prosaic: melting. Blocks of ice dam many glacial lakes, and when the ice melts, the lake can drain away. Sometimes a lake can drain in a rapid deluge, known as a glacial lake outburst flood. After flying over the region in late June 2007, scientists from Centro de Estudios Cientificos (CECS) and the Chilean Navy concluded that the likely culprit for the lake's disappearance was such a flood. Dr. Andrés Rivera, a glaciologist from CECS, described the flow. "The lake's water flowed to the north along the western margin of Glaciar Bernardo and into a big hole, [ http://www.imaginaccion.cl/cecs.html ] where the water went down into a glacier tunnel in the direction to Bernardo Fjord," he said. Bernardo Fjord empties into the Pacific Ocean. You can also download a 15-meter-resolution KMZ file of the region around the "missing" lake [ http://earthobservatory.nasa.gov/Newsroom/NewImages/Images/lagotempanos_ast_2007174.kmz ], including both April 4 and June 23, 2007, images, suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
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Dewatering Effects from the
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| Title |
Dewatering Effects from the Gujarat Earthquake |
| Description |
MISR Browse Image Viewer [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://eosweb.larc.nasa.gov/MISRBR/ ] provides access to low-resolution true-color versions of these images. This data product was generated from a portion of the imagery acquired during Terra orbits 5736 and 5969. The full-size images cover an area of 215 kilometers x 156 kilometers, and utilize data from blocks 71 to 72 within World Reference System-2 path 151. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://www-misr.jpl.nasa.gov/ ] Text by Clare Averill (Acro Service Corporation/JPL) and David J. Diner (JPL)., browse image of orbit 5969 (380 KB JPEG) On January 26, 2001, when India's Republic Day is normally celebrated, a devastating earthquake hit the state of Gujarat. About 20,000 people died and millions were injured throughout the region. The earthquake had a magnitude of 7.7 on the Richter scale. After the earthquake, local residents reported a mixture of water and sediments fountaining from the Earth. These effects, referred to as dewatering, can result from intense ground shaking by strong earthquakes in regions with shallow water tables. Scientists initially observed dewatering in parts of the Rann of Kutch (a large salt pan in northern Gujarat), and in areas close to the earthquake epicenter. Recent research utilizes the unique capabilities of the Multi-angle Imaging SpectroRadiometer (MISR) instrument to observe earthquake-related dewatering over a broader area (related story: NASA Satellite Helps Scientists See Effects of Earthquakes in Remote Areas [ http://earthobservatory.nasa.gov/Newsroom/NasaNews/2003/2003020511146.html ]). This research is published in the February 4, 2003, issue of EOS Transactions of the American Geophysical Union. These two false-color MISR images were acquired before and after the event, on January 15 and 31, respectively. The earthquake epicenter was located about 80 kilometers east of the city of Bhuj, situated in the lower part of the images. The later image depicts numerous areas where groundwater flowed up to the surface, including within the Rann of Kutch, as well as near the Indo-Pakistani border. These regions of earthquake-associated surface water are apparent up to 200 kilometers from the earthquake's epicenter. Water was observed in many remote areas, especially near the Indo-Pakistani border, which were not easily accessible to survey teams on the ground. Changes in reflection at different view angles and in the near-infrared spectral region assist with the identification of surface water, which appears here in shades of blue and purple. In these visualizations, data from the red band of MISR's most obliquely backward and forward-viewing cameras are displayed as red and blue, respectively, and data from the near-infrared band of MISR's vertically-downward viewing (nadir) camera are displayed as green. Water bodies tend to be more absorbing in the near-infrared, and to be brighter in the view acquired by the more sun-facing (in this case, the 70-degree forward) camera. This combination enhances the ability to distinguish wet surfaces. True color and multi-angle visualizations [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=4810 ] of these data were also released in April 2001. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. The |
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Dewatering Effects from the
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| Title |
Dewatering Effects from the Gujarat Earthquake |
| Description |
MISR Browse Image Viewer [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://eosweb.larc.nasa.gov/MISRBR/ ] provides access to low-resolution true-color versions of these images. This data product was generated from a portion of the imagery acquired during Terra orbits 5736 and 5969. The full-size images cover an area of 215 kilometers x 156 kilometers, and utilize data from blocks 71 to 72 within World Reference System-2 path 151. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://www-misr.jpl.nasa.gov/ ] Text by Clare Averill (Acro Service Corporation/JPL) and David J. Diner (JPL)., browse image of orbit 5969 (380 KB JPEG) On January 26, 2001, when India's Republic Day is normally celebrated, a devastating earthquake hit the state of Gujarat. About 20,000 people died and millions were injured throughout the region. The earthquake had a magnitude of 7.7 on the Richter scale. After the earthquake, local residents reported a mixture of water and sediments fountaining from the Earth. These effects, referred to as dewatering, can result from intense ground shaking by strong earthquakes in regions with shallow water tables. Scientists initially observed dewatering in parts of the Rann of Kutch (a large salt pan in northern Gujarat), and in areas close to the earthquake epicenter. Recent research utilizes the unique capabilities of the Multi-angle Imaging SpectroRadiometer (MISR) instrument to observe earthquake-related dewatering over a broader area (related story: NASA Satellite Helps Scientists See Effects of Earthquakes in Remote Areas [ http://earthobservatory.nasa.gov/Newsroom/NasaNews/2003/2003020511146.html ]). This research is published in the February 4, 2003, issue of EOS Transactions of the American Geophysical Union. These two false-color MISR images were acquired before and after the event, on January 15 and 31, respectively. The earthquake epicenter was located about 80 kilometers east of the city of Bhuj, situated in the lower part of the images. The later image depicts numerous areas where groundwater flowed up to the surface, including within the Rann of Kutch, as well as near the Indo-Pakistani border. These regions of earthquake-associated surface water are apparent up to 200 kilometers from the earthquake's epicenter. Water was observed in many remote areas, especially near the Indo-Pakistani border, which were not easily accessible to survey teams on the ground. Changes in reflection at different view angles and in the near-infrared spectral region assist with the identification of surface water, which appears here in shades of blue and purple. In these visualizations, data from the red band of MISR's most obliquely backward and forward-viewing cameras are displayed as red and blue, respectively, and data from the near-infrared band of MISR's vertically-downward viewing (nadir) camera are displayed as green. Water bodies tend to be more absorbing in the near-infrared, and to be brighter in the view acquired by the more sun-facing (in this case, the 70-degree forward) camera. This combination enhances the ability to distinguish wet surfaces. True color and multi-angle visualizations [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=4810 ] of these data were also released in April 2001. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. The |
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Haze over the Philippine Sea
| Title |
Haze over the Philippine Sea |
| Description |
The Anatahan Volcano [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=12822 ] has extended its reach over 2,220 kilometers (1,380 miles) west to blanket the Philippine Sea with a river of white haze. The volcano erupted explosively on April 6, 2005, sending as much as 50 million cubic meters of ash into the atmosphere?its largest eruption in recorded history. The haze seen here is not a product of ash however, it is a soupy fog made from tiny drops of sulfuric acid suspended in the atmosphere. This volcanic fog, called ?vog,? forms when sulfur dioxide emitted during the eruption combines with water molecules in the atmosphere to create sulfuric acid. It is not yet known how much sulfur dioxide exploded from Anatahan on April 6, or how much leaked from the volcano before and after that eruption, but the haze of sulfuric acid has now traveled to the Philippine Sea. In addition to causing eye and respiratory irritation, vog can have a big impact on climate. As this image shows, the haze is bright and reflects sunlight back into space. This decreases the amount of energy that reaches the Earth?s surface, which lowers temperatures. Large volcanic eruptions such as Pinatubo in 1991, Krakatau in 1883, or Mt. Tambora in 1815 can send enough sulfur dioxide into the atmosphere to lower temperatures around the globe, and since the tiny acid droplets remain in the atmosphere for an extended period of time, the effect can last as long as a year or two. This image of the vog over the Philippine Sea was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA?s Terra [ http://terra.nasa.gov/ ] satellite on April 20, 2005. A river of haze flows from the east in the lower right corner of the image, then snakes its way north over the water. The Philippines is immediately west of the haze, though Mindanao, the southern island of the country, appears to be covered with vog. To the left of the haze, the sun is reflecting from the smooth surface of the ocean. The effect is a silvery mirror called sunglint that extends down a narrow strip of the image where the sun?s angle was just right to reflect light directly into the sensor. The large image provided above has a resolution of 500 meters per pixel. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
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Heat Wave in North America
| Title |
Heat Wave in North America |
| Description |
Scorching summer sun, burning pavement, stinging sweat—normal for July. But in July 2006, temperatures climbed above average levels for the previous six years and stayed warm for several days. During mid-July, a heat wave settled over most of the United States, with air temperatures soaring past 100 degrees Fahrenheit (38 Celsius). Land surface temperatures climbed as well, as this image shows. Most of the United States and portions of Canada and Mexico were much warmer than they had been during the same period from 2000 to 2005. Deep red across the Midwest indicates that land surface temperatures were as much as 10 degrees Celsius warmer than the six-year average, and with the exception of the Pacific Northwest and a few other isolated region, the rest of the country was also warmer than average. The heat wave continued past the period shown here, through the end of July. In California alone, the heat killed at least 126 people, reported Reuters on July 29. This image was created from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite between July 12 and July 19, 2006. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of Zhengming Wan, MODIS Land Surface Temperature Group, Institute for Computational Earth System Science [ http://www.icess.ucsb.edu/ ], University of California, Santa Barbara. |
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Heatwave in Southern Califor
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| Title |
Heatwave in Southern California |
| Description |
September 5, 2007, marked the end of a week-long heat wave that led to 31 deaths and triggered power outages across southern California, reported the L.A. Times. Temperatures climbed above 38 degrees Celsius (100 Fahrenheit) when a high-pressure system blocked cool air from the Pacific. The effect of the heat wave on different locations in the Southwest is shown in this pair of images, taken on September 5, at 11:25 a.m. local time (18:25 UTC) by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) flying on NASA's Terra [ http://terra.nasa.gov/ ], in Northern California filters down from the top edge of the scene. NASA image created by Jesse Allen, using data obtained from the Goddard Land Processes data archives (LAADS). [ http://laads.gsfc.nasa.gov/ ], satellite. The photo-like, natural-color image (top) and corresponding land surface temperature image (bottom) illustrate the relationship between land cover, elevation, and temperature. The images show much of California and Nevada, and a smaller portion of Arizona and Utah. Not surprisingly, the hottest areas, shown in yellow, correspond with sparsely vegetated desert regions. In the natural-color image, the brush-covered Mojave Desert on the California-Nevada border is tan with splashes of pink where iron-rich sandstone is exposed. The small-leafed, woody vegetation provides little shade, allowing the Earth's surface to be exposed to the Sun. The rock-and-dirt desert absorbs sunlight, and temperatures climb (yellow areas of bottom image). The other hot spots in the image occur in the cactus-dotted Sonoran Desert, which encompasses the southernmost portions of inland California and southwestern Arizona, and the much smaller Colorado Desert west of the Salton Sea. Irrigated land south of the Salton Sea and along the Colorado River is a web of brown-green. The presence of water and vegetation in these irrigated areas makes the land cooler. Elevation also plays a role in the surface temperatures of the Sonoran Desert. Pockets of low-elevation land are much warmer than the lines of mountains that separate them, particularly in southwestern Arizona. The coolest parts of California, shown in purple and blue, are in the mountains, most prominently the Sierra Nevada, but also the San Bernardino Mountains east of Los Angeles. In the photo-like images, the mountain ranges are dark green, colored by trees. The vegetation cover and the high elevation keep the land cooler than surrounding low-elevation sites. The other significant cool spot in the image is the San Joaquin Valley. Like the irrigated farm land bordering the Salton Sea and the Colorado River, this area is kept cool by the presence of water and plants. The coldest areas in the image appear to be in Arizona, Utah, and Nevada, which are marked by streaks of dark purple. These cold signatures are from clouds.The final correlation between land cover and temperature can be seen in urban areas along the coast. In the photo-like image, Los Angles sprawls as a silver-gray patch from the coast to the San Bernardino Mountains. Since urban surfaces absorb heat, Los Angles is slightly warmer in the surface temperature image than the surrounding landscape. In the north, the San Francisco urban area is similarly warmer than its surroundings. Though the extreme temperatures raised the fire danger in Southern California, MODIS did not detect any fires in the region. Fires, marked with red dots, were burning in Central California south and east of San Francisco. Smoke from a large fire [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14497 ] |
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Dust over the Arabian Sea
| Title |
Dust over the Arabian Sea |
| Description |
A number of jets of windblown desert dust (light brown plumes) were blowing over the Arabian Sea on March 2, 2003. Originating from the Arabian Peninsula (middle left) as well as Iran and Pakistan (top center and top right, respectively) the dust obscures the surface over much of the region. Notice the very thin line of clouds, much whiter and brighter than the dust, running southeastward over the Gulf of Oman and demarcating the edge of the front. Another similar cloud pattern can be seen south of Oman. Notice also the vertical discontinuity running from top to bottom through the center of this scene. This image was made using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors flying aboard NASA's Terra and Aqua satellites at hours apart on the same day. The scene appears a bit different to each satellite not only because the clouds and dust plumes are moving, but also because the relative angle of the sun is changing. In the righthand image (Aqua MODIS), you can discern more dark green structure in the Indian Ocean, indicating the presence of phytoplankton. The intense biological activity going on there is quite likely being enhanced by the influx of iron-rich desert dust settling into the waters there over recent days. The high-resolution image provided above is 500 meters per pixel. The MODIS Rapid Response System provides this image at MODIS' maximum spatial resolution of 250 meters. Image courtesy Jacques Descloitres, MODIS Rapid Response Team, NASA GSFC |
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Dust Storm over Afghanistan
| Title |
Dust Storm over Afghanistan |
| Description |
On August 17, 2004, the Moderate Resolution Imaging Spectroradiometer (MODIS), aboard NASA?s Terra satellite, observed a large plume of dust blowing out of the Sistan Basin and fanning out over a large portion of southern Afghanistan and northern Pakistan. Once a lush oasis spanning more than 2,000 square kilometers (800 square miles), the Hamoun Wetlands [ http://earthobservatory.nasa.gov/Study/hamoun/ ] were a major source of food and shelter for the people of Central Asia. Within the last decade, however, human mismanagement of the rivers feeding the once fertile wetlands has converted them mostly into salt flats?desiccated and almost devoid of life. The light sediment that once rested on the bottom of the Hamoun?s marshes now lies exposed to sun and wind. The frequent strong winds blowing through the region easily scoop up the dried silt and carry it aloft for hundreds or even thousands of kilometers. Such dust storms appear to be increasing in frequency and severity as residents in southern Afghanistan report that, during the last several years, the skies overhead have been the dustiest in living memory. The solid black line in this scene shows the border between the countries of Iran (to the left), Afghanistan (top), and Pakistan (bottom right). North in this image is toward the top. The high-resolution copy available here is 250 meters per pixel. There are also additional resolutions available. NASA image courtesy Jacques Descloitres, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
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Dust Storms from Africa's Bo
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| Title |
Dust Storms from Africa's Bodele Depression |
| Description |
Once serving as part of the floor for a much larger Lake Chad, the area now known as the Bodele Depression, located at the southern edge of the Sahara Desert in north central Africa, is slowly being transformed into a desert landscape. In the mid-1960s, Lake Chad was about the size of Lake Erie. But persistent drought conditions coupled with increased demand for freshwater for irrigation have reduced Lake Chad to about 5 percent of its former size. As the waters receded, the silts and sediments resting on the lakebed were left to dry in the scorching African sun. The small grains of the silty sand are easily swept up by the strong wind gusts that occasionally blow over the region. Once heaved aloft, the Bodele dust can be carried for hundreds or even thousands of kilometers. The remnants of Lake Chad appear as the olive-green feature set amid the tan and light brown hues of the surrounding landscape where the countries of Chad, Niger, Nigeria, and Cameroon all share borders. The Bodele Depression was the source of some very impressive dust storms that have swept over West Africa [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=11939 ] and the Cape Verde Islands [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=11935 ] in recent days. This true-color image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA?s Terra satellite, on February 7, 2004. A similar image was acquired later that same day by the MODIS instrument aboard NASA?s Aqua satellite. The high-resolution image available here is 500 meters per pixel, but both scenes are available at up to 250 meters per pixel?the sensor?s maximum resolution. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/ ] at NASA GSFC |
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Dust Storms from Africa's Bo
…
| Title |
Dust Storms from Africa's Bodele Depression |
| Description |
Once serving as part of the floor for a much larger Lake Chad, the area now known as the Bodele Depression, located at the southern edge of the Sahara Desert in north central Africa, is slowly being transformed into a desert landscape. In the mid-1960s, Lake Chad was about the size of Lake Erie. But persistent drought conditions coupled with increased demand for freshwater for irrigation have reduced Lake Chad to about 5 percent of its former size. As the waters receded, the silts and sediments resting on the lakebed were left to dry in the scorching African sun. The small grains of the silty sand are easily swept up by the strong wind gusts that occasionally blow over the region. Once heaved aloft, the Bodele dust can be carried for hundreds or even thousands of kilometers. The remnants of Lake Chad appear as the olive-green feature set amid the tan and light brown hues of the surrounding landscape where the countries of Chad, Niger, Nigeria, and Cameroon all share borders. The Bodele Depression was the source of some very impressive dust storms that have swept over West Africa [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=11939 ] and the Cape Verde Islands [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=11935 ] in recent days. This true-color image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA?s Terra satellite, on February 7, 2004. A similar image was acquired later that same day by the MODIS instrument aboard NASA?s Aqua satellite. The high-resolution image available here is 500 meters per pixel, but both scenes are available at up to 250 meters per pixel?the sensor?s maximum resolution. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/ ] at NASA GSFC |
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Indonesia?s Ruang Volcano Er
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| Title |
Indonesia?s Ruang Volcano Erupts |
| Description |
*Full-resolution Images:* ÿÿÿTerra MODIS at 1:55 UTC (1.1 MB) ÿÿÿAqua MODIS at 4:50 UTC (748 KB) Mount Ruang, a stratovolcano in the Indonesian Sulawesi Islands, erupted on September 25, 2002, sending a large plume of ash (gray pixels) streaming westward toward Borneo and Sumatra. The eruption was preceded by earthquakes on the day before, followed by a thick, black column of volcanic ash ejected as high as 5,000 m into the sky on the 25th. While no fatalities were reported, more than 1,000 residents on Ruang Island were forced to evacuate to a nearby island. This comparison pair of true-color images was acquired by the Moderate Resolution Imaging Spectroradiometer, flying aboard NASA's Terra and Aqua satellites, on September 25. The top image was acquired by Terra MODIS at 1:55 UTC, while the bottom image was acquired by Aqua MODIS at 4:50 UTC. Notice how much the plume grew in that 3-hour span of time. (Note: the Aqua image appears noticeably different because the relative sun angle makes both the plume and the ocean surface appear much brighter.) Images courtesy Jacques Descloitres, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/ ] at NASA GSFC |
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Indonesia?s Ruang Volcano Er
…
| Title |
Indonesia?s Ruang Volcano Erupts |
| Description |
*Full-resolution Images:* ÿÿÿTerra MODIS at 1:55 UTC (1.1 MB) ÿÿÿAqua MODIS at 4:50 UTC (748 KB) Mount Ruang, a stratovolcano in the Indonesian Sulawesi Islands, erupted on September 25, 2002, sending a large plume of ash (gray pixels) streaming westward toward Borneo and Sumatra. The eruption was preceded by earthquakes on the day before, followed by a thick, black column of volcanic ash ejected as high as 5,000 m into the sky on the 25th. While no fatalities were reported, more than 1,000 residents on Ruang Island were forced to evacuate to a nearby island. This comparison pair of true-color images was acquired by the Moderate Resolution Imaging Spectroradiometer, flying aboard NASA's Terra and Aqua satellites, on September 25. The top image was acquired by Terra MODIS at 1:55 UTC, while the bottom image was acquired by Aqua MODIS at 4:50 UTC. Notice how much the plume grew in that 3-hour span of time. (Note: the Aqua image appears noticeably different because the relative sun angle makes both the plume and the ocean surface appear much brighter.) Images courtesy Jacques Descloitres, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/ ] at NASA GSFC |
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Indonesia?s Ruang Volcano Er
…
| Title |
Indonesia?s Ruang Volcano Erupts |
| Description |
*Full-resolution Images:* ÿÿÿTerra MODIS at 1:55 UTC (1.1 MB) ÿÿÿAqua MODIS at 4:50 UTC (748 KB) Mount Ruang, a stratovolcano in the Indonesian Sulawesi Islands, erupted on September 25, 2002, sending a large plume of ash (gray pixels) streaming westward toward Borneo and Sumatra. The eruption was preceded by earthquakes on the day before, followed by a thick, black column of volcanic ash ejected as high as 5,000 m into the sky on the 25th. While no fatalities were reported, more than 1,000 residents on Ruang Island were forced to evacuate to a nearby island. This comparison pair of true-color images was acquired by the Moderate Resolution Imaging Spectroradiometer, flying aboard NASA's Terra and Aqua satellites, on September 25. The top image was acquired by Terra MODIS at 1:55 UTC, while the bottom image was acquired by Aqua MODIS at 4:50 UTC. Notice how much the plume grew in that 3-hour span of time. (Note: the Aqua image appears noticeably different because the relative sun angle makes both the plume and the ocean surface appear much brighter.) Images courtesy Jacques Descloitres, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/ ] at NASA GSFC |
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Lake Effect Snow in the Unit
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| Title |
Lake Effect Snow in the United States |
| Description |
Like light radiating from the Sun, streamers of snow streak southeast from the Great Lakes in this photo-like image, collected by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite on December 9, 2006. The snow seen here came from two different storms. The broad swath of white extending from the left edge of the image to Lake Michigan was deposited on December 1 by a powerful winter storm [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17480 ] that left thousands without power for many days. The snow on the southeastern side of the Great Lakes, however, fell on December 7 and December 8 as lake-effect snow. Lake-effect snow occurs along the southeastern edge of the Great Lakes when icy wind blows across the lakes from Canada. The wind picks up relatively warm, moist air over the lakes and pushes it over land, where the air is cooler. When the moist air encounters cooler temperatures over land, the water condenses into precipitation, which in this case fell as snow. The signature of lake-effect snow is striking in this image. A field of white lines the southeastern shores of each of the Great Lakes. The strong winds that generated the snow left their imprint in the form of long streamers of snow that extend all the way to the deep brown folds of the Appalachian Mountains along the right edge of the image.Daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/ ] of the United States can be viewed on the MODIS Rapid Response web site. The tiny red dots in this image indicate where MODIS detected fires. NASA image courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
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Eruption of Anatahan
| Title |
Eruption of Anatahan |
| Description |
Volcanic tremors resumed under the Anatahan Volcano on May 18, 2005, according to the current update [ http://hvo.wr.usgs.gov/cnmi/update.html ] from the United States Geological Survey and the Emergency Management Office for the Northern Mariana Islands. Tremor activity peaked on May 20 then declined until May 23. The tremor amplitudes have since resurged. Anatahan still showed signs of activity when the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ], flying on the Terra [ http://terra.nasa.gov/ ] satellite, acquired this image on May 25, 2005. Volcanic tremors occur when magma rises inside the volcano or when the volcano erupts. In this image, Anatahan, on the right, is clearly erupting, sending a brown plume of ash westward over the Philippine Sea. Further west, volcanic gasses from a previous eruption have gathered in a thick white haze called "vog." When sulfur dioxide and other volcanic pollutants mix with water and oxygen in the presence of sunlight, the result is volcanic smog, or vog [ http://hvo.wr.usgs.gov/volcanowatch/1996/96_05_29.html ], a potentially hazardous material. This picture shows all the ingredients necessary to make vog: a volcanic ash plume, plenty of water, and sunlight. The sunlight is particularly obvious as the sunglint in the center of the image. When the sun and the satellite are at the same angle to the ocean, sunlight bounces off the ocean surface and reflects directly into the satellite sensor. Image by Jesse Allen, based on data from the MODIS Rapid Response Team at NASA Goddard Space Flight Center. |
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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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Mount St. Helens
| Title |
Mount St. Helens |
| Description |
Hot lava had broken through the surface of the growing lava dome on Mount St. Helens when the MASTER sensor took this image in the early morning hours of October 13, 2004. MASTER, which stands for MODIS/ASTER Airborne Simulator, is an aircraft- mounted remote sensing device built to simulate the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov/ ]) and Advanced Spaceborne Thermal Emission and Reflection Radiometer [ http://asterweb.jpl.nasa.gov/ ] (ASTER) instruments on NASA's Terra [ http://terra.nasa.gov/ ] satellite. The top image was made from MASTER's thermal sensitive bands, and shows the heat in the volcano's crater. A brilliant white spot on the southwest side of the crater is hot lava bubbling to the surface. Smaller, less intense hot spots around the crater have formed where magma near the surface has heated the rock above it. The dark area around the lava dome is the crater. Shielded from the sun and covered with snow, the dark crater floor is cooler than the surrounding landscape, which appears red. A plume of steam rising from the lava dome (colored purple) drifts southeast in this image. The plume and crater floor are more visible in the lower, true color image. Acquired just after dawn, the image has few shadows and low contrast. An image composed of thermal infrared and visible light wavelengths reveals more details around the mountain. The volcanic plume is bright cyan, the cool crater is purple, and snow is light blue. To the north of the volcano, two bright red lines extend from south to north. These are warm-water streams, possibly heated by the active volcano. NASA images courtesy Jeff Myers, MASTER [ http://masterweb.jpl.nasa.gov/ ] instrument team, NASA Ames Research Center |
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Mount St. Helens
| Title |
Mount St. Helens |
| Description |
Hot lava had broken through the surface of the growing lava dome on Mount St. Helens when the MASTER sensor took this image in the early morning hours of October 13, 2004. MASTER, which stands for MODIS/ASTER Airborne Simulator, is an aircraft- mounted remote sensing device built to simulate the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov/ ]) and Advanced Spaceborne Thermal Emission and Reflection Radiometer [ http://asterweb.jpl.nasa.gov/ ] (ASTER) instruments on NASA's Terra [ http://terra.nasa.gov/ ] satellite. The top image was made from MASTER's thermal sensitive bands, and shows the heat in the volcano's crater. A brilliant white spot on the southwest side of the crater is hot lava bubbling to the surface. Smaller, less intense hot spots around the crater have formed where magma near the surface has heated the rock above it. The dark area around the lava dome is the crater. Shielded from the sun and covered with snow, the dark crater floor is cooler than the surrounding landscape, which appears red. A plume of steam rising from the lava dome (colored purple) drifts southeast in this image. The plume and crater floor are more visible in the lower, true color image. Acquired just after dawn, the image has few shadows and low contrast. An image composed of thermal infrared and visible light wavelengths reveals more details around the mountain. The volcanic plume is bright cyan, the cool crater is purple, and snow is light blue. To the north of the volcano, two bright red lines extend from south to north. These are warm-water streams, possibly heated by the active volcano. NASA images courtesy Jeff Myers, MASTER [ http://masterweb.jpl.nasa.gov/ ] instrument team, NASA Ames Research Center |
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Fires in Borneo
| Title |
Fires in Borneo |
| Description |
In southern Borneo, a cluster of fires was burning on September 18, 2005. These and other fires have been creating a severe air quality problem for the island throughout September. The image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite, active fires have been marked with red dots. One reason fires on Borneo are so smoky is that they are usually burning in peat swamp forests. The island's low-lying areas are home to swampy forests where leaves and other organic matter decay very slowly because of the soggy conditions. The dead material accumulates in thick layers called peat. When peat dries out, either due to drought or because of logging that opens the forest canopy and exposes the ground to the Sun, the peat become flammable. Fires started in peat forests can burn out of control for months, churning out thick smoke. NASA image created by Jesse Allen, Earth Observatory, using data obtained courtesy of the MODIS Rapid Response team. |
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Petrol Depot Fire in the Uni
…
| Title |
Petrol Depot Fire in the United Kingdom |
| Description |
Sunday, December 11, 2005, was a day without sun for many Londoners. At about 6 a.m. local time, an explosion rocked a fuel depot in Hertfordshire, approximately 40 kilometers (25 miles) north of London. The ensuing oil fire sent thick clouds of sun-blocking black smoke billowing over London and South England. By 11:50 a.m., when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) flew over on NASA's Terra [ http://terra.nasa.gov/ ] satellite, the smoke had fanned south over tens of kilometers. London, normally a large cement-colored circle on the landscape, was not even visible beneath the smoke. Nearly three hours later when Aqua [ http://aqua.nasa.gov/ ] MODIS flew over, the fire was still burning, and the smoke had spread still farther. By December 12 [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13281 ], the smoke had thinned to a single plume. The extent of the smoke is easier to see in the false-color images, right, which were created using light from the shortwave and near-infrared part of the electromagnetic spectrum. In these images, the dark smoke stands out clearly against the brilliant green of the plant-covered land. At the source of the smoke, the intense heat of the fire glows in the infrared. According to news reports, the fire was the largest of its kind ever seen in Europe. British health officials advised those living under the smoke plume to remain indoors. The smoke contains small particles, soot, that may cause irritation when inhaled, but no long-term health effects were expected. The smoke also contains gases like carbon monoxide, carbon dioxide, and sulphur dioxide. For more information about the health impacts of the smoke, see the Health Protection Agency [ http://www.hpa.org.uk/explosions/hemel_Q_As.htm ] web site. The large images provided above are at MODIS' maximum resolution of 250 meters per pixel. Daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Europe_2_01/2005345 ] of the region are available from the MODIS Rapid Response Team in a variety of resolutions. NASA images courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
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Petrol Depot Fire in the Uni
…
| Title |
Petrol Depot Fire in the United Kingdom |
| Description |
Sunday, December 11, 2005, was a day without sun for many Londoners. At about 6 a.m. local time, an explosion rocked a fuel depot in Hertfordshire, approximately 40 kilometers (25 miles) north of London. The ensuing oil fire sent thick clouds of sun-blocking black smoke billowing over London and South England. By 11:50 a.m., when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) flew over on NASA's Terra [ http://terra.nasa.gov/ ] satellite, the smoke had fanned south over tens of kilometers. London, normally a large cement-colored circle on the landscape, was not even visible beneath the smoke. Nearly three hours later when Aqua [ http://aqua.nasa.gov/ ] MODIS flew over, the fire was still burning, and the smoke had spread still farther. By December 12 [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13281 ], the smoke had thinned to a single plume. The extent of the smoke is easier to see in the false-color images, right, which were created using light from the shortwave and near-infrared part of the electromagnetic spectrum. In these images, the dark smoke stands out clearly against the brilliant green of the plant-covered land. At the source of the smoke, the intense heat of the fire glows in the infrared. According to news reports, the fire was the largest of its kind ever seen in Europe. British health officials advised those living under the smoke plume to remain indoors. The smoke contains small particles, soot, that may cause irritation when inhaled, but no long-term health effects were expected. The smoke also contains gases like carbon monoxide, carbon dioxide, and sulphur dioxide. For more information about the health impacts of the smoke, see the Health Protection Agency [ http://www.hpa.org.uk/explosions/hemel_Q_As.htm ] web site. The large images provided above are at MODIS' maximum resolution of 250 meters per pixel. Daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Europe_2_01/2005345 ] of the region are available from the MODIS Rapid Response Team in a variety of resolutions. NASA images courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
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Petrol Depot Fire in the Uni
…
| Title |
Petrol Depot Fire in the United Kingdom |
| Description |
Sunday, December 11, 2005, was a day without sun for many Londoners. At about 6 a.m. local time, an explosion rocked a fuel depot in Hertfordshire, approximately 40 kilometers (25 miles) north of London. The ensuing oil fire sent thick clouds of sun-blocking black smoke billowing over London and South England. By 11:50 a.m., when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) flew over on NASA's Terra [ http://terra.nasa.gov/ ] satellite, the smoke had fanned south over tens of kilometers. London, normally a large cement-colored circle on the landscape, was not even visible beneath the smoke. Nearly three hours later when Aqua [ http://aqua.nasa.gov/ ] MODIS flew over, the fire was still burning, and the smoke had spread still farther. By December 12 [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13281 ], the smoke had thinned to a single plume. The extent of the smoke is easier to see in the false-color images, right, which were created using light from the shortwave and near-infrared part of the electromagnetic spectrum. In these images, the dark smoke stands out clearly against the brilliant green of the plant-covered land. At the source of the smoke, the intense heat of the fire glows in the infrared. According to news reports, the fire was the largest of its kind ever seen in Europe. British health officials advised those living under the smoke plume to remain indoors. The smoke contains small particles, soot, that may cause irritation when inhaled, but no long-term health effects were expected. The smoke also contains gases like carbon monoxide, carbon dioxide, and sulphur dioxide. For more information about the health impacts of the smoke, see the Health Protection Agency [ http://www.hpa.org.uk/explosions/hemel_Q_As.htm ] web site. The large images provided above are at MODIS' maximum resolution of 250 meters per pixel. Daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Europe_2_01/2005345 ] of the region are available from the MODIS Rapid Response Team in a variety of resolutions. NASA images courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
|
Petrol Depot Fire in the Uni
…
| Title |
Petrol Depot Fire in the United Kingdom |
| Description |
Sunday, December 11, 2005, was a day without sun for many Londoners. At about 6 a.m. local time, an explosion rocked a fuel depot in Hertfordshire, approximately 40 kilometers (25 miles) north of London. The ensuing oil fire sent thick clouds of sun-blocking black smoke billowing over London and South England. By 11:50 a.m., when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) flew over on NASA's Terra [ http://terra.nasa.gov/ ] satellite, the smoke had fanned south over tens of kilometers. London, normally a large cement-colored circle on the landscape, was not even visible beneath the smoke. Nearly three hours later when Aqua [ http://aqua.nasa.gov/ ] MODIS flew over, the fire was still burning, and the smoke had spread still farther. By December 12 [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13281 ], the smoke had thinned to a single plume. The extent of the smoke is easier to see in the false-color images, right, which were created using light from the shortwave and near-infrared part of the electromagnetic spectrum. In these images, the dark smoke stands out clearly against the brilliant green of the plant-covered land. At the source of the smoke, the intense heat of the fire glows in the infrared. According to news reports, the fire was the largest of its kind ever seen in Europe. British health officials advised those living under the smoke plume to remain indoors. The smoke contains small particles, soot, that may cause irritation when inhaled, but no long-term health effects were expected. The smoke also contains gases like carbon monoxide, carbon dioxide, and sulphur dioxide. For more information about the health impacts of the smoke, see the Health Protection Agency [ http://www.hpa.org.uk/explosions/hemel_Q_As.htm ] web site. The large images provided above are at MODIS' maximum resolution of 250 meters per pixel. Daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Europe_2_01/2005345 ] of the region are available from the MODIS Rapid Response Team in a variety of resolutions. NASA images courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
|
Petrol Depot Fire in the Uni
…
| Title |
Petrol Depot Fire in the United Kingdom |
| Description |
Sunday, December 11, 2005, was a day without sun for many Londoners. At about 6 a.m. local time, an explosion rocked a fuel depot in Hertfordshire, approximately 40 kilometers (25 miles) north of London. The ensuing oil fire sent thick clouds of sun-blocking black smoke billowing over London and South England. By 11:50 a.m., when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) flew over on NASA's Terra [ http://terra.nasa.gov/ ] satellite, the smoke had fanned south over tens of kilometers. London, normally a large cement-colored circle on the landscape, was not even visible beneath the smoke. Nearly three hours later when Aqua [ http://aqua.nasa.gov/ ] MODIS flew over, the fire was still burning, and the smoke had spread still farther. By December 12 [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13281 ], the smoke had thinned to a single plume. The extent of the smoke is easier to see in the false-color images, right, which were created using light from the shortwave and near-infrared part of the electromagnetic spectrum. In these images, the dark smoke stands out clearly against the brilliant green of the plant-covered land. At the source of the smoke, the intense heat of the fire glows in the infrared. According to news reports, the fire was the largest of its kind ever seen in Europe. British health officials advised those living under the smoke plume to remain indoors. The smoke contains small particles, soot, that may cause irritation when inhaled, but no long-term health effects were expected. The smoke also contains gases like carbon monoxide, carbon dioxide, and sulphur dioxide. For more information about the health impacts of the smoke, see the Health Protection Agency [ http://www.hpa.org.uk/explosions/hemel_Q_As.htm ] web site. The large images provided above are at MODIS' maximum resolution of 250 meters per pixel. Daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Europe_2_01/2005345 ] of the region are available from the MODIS Rapid Response Team in a variety of resolutions. NASA images courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
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Fires in Eastern China
| Title |
Fires in Eastern China |
| Description |
Scores of active fires were burning in the southern Shandong (top part of image), Anhui (lower left), and Jiangsu (lower right) provinces of eastern China on June 11, 2006. This Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] image from the Terra [ http://terra.nasa.gov ] satellite shows active fire locations marked in red. Grayish smoke hangs over the center of the scene. According to reports from the USDA Foreign Agricultural Service, the region's winter wheat harvest is wrapping up, and these fires may be for post-harvest clean-up of fields. Below image center, sun glints brightly off Hongze Lake, while in the Yellow Sea south of Haizhou Bay, yellow-brown sediment fans out from the coast. A related image [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13631 ] of this region showing dust, smoke, and fires is included in the Natural Hazards: Dust and Smoke section. The high-resolution image provided above has a spatial resolution of 250 meters per pixel. The MODIS Rapid Response System provides this image in additional resolutions and formats. [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?FAS_China4/2006162/ ] NASA image courtesy the MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center |
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Record Hot April in Australi
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| Title |
Record Hot April in Australia |
| Description |
Record heat stifled Australia in April 2005. The average temperature for the entire continent was 2.9 degrees Celsius above average, making this the warmest April on record. The high temperatures were accompanied by dry skies, with rainfall totals well below average for many areas. This image shows just how much of Australia sweltered under hotter-than-normal temperatures during April 2005. The image was created using surface temperature data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA?s Terra [ http://terra.nasa.gov/ ] satellite. Deep red over most of the continent reveal where temperatures were hotter in April 2005 than the average April temperature between 2000 and 2004. Darker red spots show where temperatures spiked, while tan and blues show temperatures much closer to average. The surface temperatures shown here are different from the air temperatures reported on the evening news. Because the ground absorbs energy from the sun, surface temperatures are often much warmer than air temperatures, for example, a sandy beach can be unbearably hot even though the air temperature is comfortable. While air temperatures may not have soared as high as 15 degrees Celsius above average as the image shows the ground temperatures doing in places, they did set new records throughout the country. NASA image by Jesse Allen, based on data from Zhengming Wan, MODIS Land Surface Temperature Group, Institute for Computational Earth System Science [ http://www.icess.ucsb.edu/ ], University of California, Santa Barbara |
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Record Hot April in Australi
…
| Title |
Record Hot April in Australia |
| Description |
Record heat stifled Australia in April 2005. The average temperature for the entire continent was 2.9 degrees Celsius above average, making this the warmest April on record. The high temperatures were accompanied by dry skies, with rainfall totals well below average for many areas. This image shows just how much of Australia sweltered under hotter-than-normal temperatures during April 2005. The image was created using surface temperature data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA?s Terra [ http://terra.nasa.gov/ ] satellite. Deep red over most of the continent reveal where temperatures were hotter in April 2005 than the average April temperature between 2000 and 2004. Darker red spots show where temperatures spiked, while tan and blues show temperatures much closer to average. The surface temperatures shown here are different from the air temperatures reported on the evening news. Because the ground absorbs energy from the sun, surface temperatures are often much warmer than air temperatures, for example, a sandy beach can be unbearably hot even though the air temperature is comfortable. While air temperatures may not have soared as high as 15 degrees Celsius above average as the image shows the ground temperatures doing in places, they did set new records throughout the country. NASA image by Jesse Allen, based on data from Zhengming Wan, MODIS Land Surface Temperature Group, Institute for Computational Earth System Science [ http://www.icess.ucsb.edu/ ], University of California, Santa Barbara |
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Fires in Mexico and Central
…
| Title |
Fires in Mexico and Central America |
| Description |
Numerous fires were detected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on April 13, 2004, as the spacecraft passed over southern Mexico. The fires are marked with orange dots in this scene, which centers on the region south of Lake Chapala (northwest of image center). The lake and the Pacific Ocean are brightened by sun glint on the water. North of the lake is the city of Guadalajara. The widespread nature of the fires and the time of year suggests that these fires are being set intentionally for agricultural purposes. Though not necessarily hazardous, such large-scale burning can have a strong impact on weather, climate, human health, and natural resources. Image by Jesse Allen, based on data from the MODIS Rapid Response Team, NASA-GSFC |
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Rice Cultivation in Northwes
…
| 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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Saharan Dust off West Africa
| Title |
Saharan Dust off West Africa |
| Description |
A massive plume of Saharan desert dust (light brown pixels) continued its westward trek across the Atlantic Ocean on March 4, 2003, being held aloft and swept along by strong winds. The plume covers a vast expanse of ocean, roughly equal in extent to about half the land area of the contiguous United States. This true-color image of the dust storm was made by stitching together two images acquired on the same day by NASA's Terra and Aqua satellites. Notice the vertical discontinuity running from top to bottom through the center of this scene. The image was made using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors flying aboard both spacecraft at hours apart on March 4. The scene appears a bit different to each satellite not only because the clouds and dust plumes are moving, but also because the relative angle of the sun is changing. In the righthand image (Aqua MODIS), you can discern more dark green structure in the Indian Ocean, indicating the presence of phytoplankton. The intense biological activity going on there is quite likely being enhanced by the influx of iron-rich desert dust settling into the waters there over recent days. Image courtesy Jeffrey Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Saharan Dust off West Africa
| Title |
Saharan Dust off West Africa |
| Description |
A massive plume of Saharan desert dust (light brown pixels) continued its westward trek across the Atlantic Ocean on March 5, 2003, being held aloft and swept along by strong winds. The plume, which originated on March 2, now covers a vast expanse of ocean and appears bound to reach the other side of the Atlantic. This true-color image of the dust storm was made by stitching together four images acquired on the same day by NASA?s Terra and Aqua satellites. The image was made using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors flying aboard both spacecraft at hours apart on March 5. Notice the vertical discontinuities running from top to bottom through the center of this scene, indicating the width sensor's viewing swath on each subsequent overpass. The scene appears a bit different to each satellite not only because the clouds and dust plumes are moving, but also because the relative angle of the sun is changing. Image courtesy Jeffrey Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Saharan Dust off West Africa
| Title |
Saharan Dust off West Africa |
| Description |
A massive plume of Saharan desert dust (light brown pixels) continued its westward trek across the Atlantic Ocean on March 6, 2003, being held aloft and swept along by strong winds. The plume, which originated on March 2, now covers a vast expanse of ocean and appears bound to reach the other side of the Atlantic. This true-color image of the dust storm was made by stitching together four images acquired on the same day by NASA?s Terra and Aqua satellites. The image was made using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors flying aboard both spacecraft at hours apart on March 6. Notice the vertical discontinuities running from top to bottom through the center of this scene, indicating the width sensor's viewing swath on each subsequent overpass. The scene appears a bit different to each satellite not only because the clouds and dust plumes are moving, but also because the relative angle of the sun is changing. The white triangles at the bottom of the image show where no data were acquired due to gaps between subsequent viewing swaths. Image courtesy Jeffrey Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Snow in the Hindu Kush
| Title |
Snow in the Hindu Kush |
| Description |
The most severe winter to hit southwest Asia in decades has cost hundreds of lives in Pakistan, India, and Afghanistan. Heavy snow continues to fall over the Himalaya Mountains in both Indian-administered and Pakistan-administered Kashmir and in the Hindu Kush of Afghanistan. As the above image shows, both mountains and valleys are buried in snow across the region, with the exception of the Indus River valley in Pakistan. The snow has isolated many communities, stranding them without access to food supplies. Most of the deaths, however, have occurred as people have been trapped under avalanches in the steep mountains. At least 230 people died in Indian-administered Kashmir, many of them in a series of avalanches near the capital, Srinagar, where 4.5 meters (15 feet) of snow has fallen. When the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA?s Terra [ http://terra.nasa.gov/ ] satellite acquired this image on February 22, 2005, the clouds had cleared and the sun shone over Kashmir. Low cloud, slightly smoother and duller white than snow, fills the valley around Srinagar. In the high mountains exposed to the sun, the avalanche hazard could increase as melting snow becomes unstable. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
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Total Solar Eclipse over Afr
…
| Title |
Total Solar Eclipse over Africa and the Mediterranean |
| Description |
At 10:40 UTC (Coordinated Universal Time), NASA's Aqua [ http://aqua.nasa.gov ] satellite flew over the eastern Mediterranean as the shadow of the Moon traveled across Libya and the Mediterranean. As Aqua passed over, the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] captured the top image in this pair. The deep shadow cast by the Moon as it passed in front of the Sun is clearly visible on the Earth, in stark contrast to the daylight view of the same area captured just an hour earlier by the MODIS on the Terra [ http://terra.nasa.gov ] satellite. During the eclipse, clouds and snow were still visible, but the land surface below was lost in darkness. NASA images created by Jesse Allen, Earth Observatory, using data obtained courtesy of the MODIS Rapid Response team. |
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Total Solar Eclipse over Afr
…
| Title |
Total Solar Eclipse over Africa and the Mediterranean |
| Description |
At 10:40 UTC (Coordinated Universal Time), NASA's Aqua [ http://aqua.nasa.gov ] satellite flew over the eastern Mediterranean as the shadow of the Moon traveled across Libya and the Mediterranean. As Aqua passed over, the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] captured the top image in this pair. The deep shadow cast by the Moon as it passed in front of the Sun is clearly visible on the Earth, in stark contrast to the daylight view of the same area captured just an hour earlier by the MODIS on the Terra [ http://terra.nasa.gov ] satellite. During the eclipse, clouds and snow were still visible, but the land surface below was lost in darkness. NASA images created by Jesse Allen, Earth Observatory, using data obtained courtesy of the MODIS Rapid Response team. |
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Total solar eclipse over Ant
…
| Title |
Total solar eclipse over Antarctica |
| Description |
The moon cast a long shadow over Antarctica on November 23, 2003, in a total solar eclipse. The sun typically hangs low on the horizon during the southernmost continent's almost-summer months, so when the Moon moved between the Sun and the Earth, its shadow fell in a roughly 500-kilometer long oval like the long shadows of a early summer dawn. At the time this image was taken, the sun was at approximately 15 degrees above the horizon. The shadow's long circular shape is the same pattern a flashlight casts an the floor when held at a similar angle. The moon's shadow has two parts: the fuzzy outer shadow, the penumbra, and the dark inner shadow, the umbra. Within the umbra, the sun is completely blocked. A person standing on the ground sees a glowing black disk in front of the sun?the disk is the moon, and the glow is the sun's corona. In the penumbra, the ground observer sees the moon covering part of the sun. Both the penumbra and the umbra are visible in this true-color image. The Moderate Resolution Imaging Spectroradiometer [ http://modis.gsfc.nasa.gov ] (MODIS) on the Aqua [ http://aqua.nasa.gov/ ] satellite captured this image of the eclipse between 23:15 and 23:20 UTC. The Terra [ http://terra.nasa.gov/ ] satellite captured a similar image [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2003327-1123/Antarctica.A2003327.2255 ] of the eclipse. The eclipse started at 22:08 UTC, and the shadow passed from the surface of the earth a little over an hour later at 23:20 UTC. The sun's light was completely blocked at 22:49 for one minute and 55 seconds. At the time this image was taken, the sun was just rising over Antarctica, tinting the mountains a delicate pink, even within the shadow of the eclipse. Beyond the dark upper left corner, the sun has not yet driven away night's darkness. The bluish tones of the snow reveal how Antarctica appears from space without atmospheric correction. The shadow covers Queen Maud Land, Antarctica, with its tip pointing towards Africa. The South Pole is just beyond the right corner of the image. The moon is not the only thing throwing shadows across the landscape in this image. On the top left, the Pensacola Mountains make long horizontal shadows on the ice. Patches of low cloud along the left side of the umbra are also leaving a dark smudge on the surface. This image is available in multiple resolutions [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2003327-1123/Antarctica2.A2003327.2320 ]. Image courtesy Jacques Descloitres, MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
|
Total solar eclipse over Ant
…
| Title |
Total solar eclipse over Antarctica |
| Description |
The moon cast a long shadow over Antarctica on November 23, 2003, in a total solar eclipse. The sun typically hangs low on the horizon during the southernmost continent's almost-summer months, so when the Moon moved between the Sun and the Earth, its shadow fell in a roughly 500-kilometer long oval like the long shadows of a early summer dawn. At the time this image was taken, the sun was at approximately 15 degrees above the horizon. The shadow's long circular shape is the same pattern a flashlight casts an the floor when held at a similar angle. The moon's shadow has two parts: the fuzzy outer shadow, the penumbra, and the dark inner shadow, the umbra. Within the umbra, the sun is completely blocked. A person standing on the ground sees a glowing black disk in front of the sun?the disk is the moon, and the glow is the sun's corona. In the penumbra, the ground observer sees the moon covering part of the sun. Both the penumbra and the umbra are visible in this true-color image. The Moderate Resolution Imaging Spectroradiometer [ http://modis.gsfc.nasa.gov ] (MODIS) on the Aqua [ http://aqua.nasa.gov/ ] satellite captured this image of the eclipse between 23:15 and 23:20 UTC. The Terra [ http://terra.nasa.gov/ ] satellite captured a similar image [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2003327-1123/Antarctica.A2003327.2255 ] of the eclipse. The eclipse started at 22:08 UTC, and the shadow passed from the surface of the earth a little over an hour later at 23:20 UTC. The sun's light was completely blocked at 22:49 for one minute and 55 seconds. At the time this image was taken, the sun was just rising over Antarctica, tinting the mountains a delicate pink, even within the shadow of the eclipse. Beyond the dark upper left corner, the sun has not yet driven away night's darkness. The bluish tones of the snow reveal how Antarctica appears from space without atmospheric correction. The shadow covers Queen Maud Land, Antarctica, with its tip pointing towards Africa. The South Pole is just beyond the right corner of the image. The moon is not the only thing throwing shadows across the landscape in this image. On the top left, the Pensacola Mountains make long horizontal shadows on the ice. Patches of low cloud along the left side of the umbra are also leaving a dark smudge on the surface. This image is available in multiple resolutions [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2003327-1123/Antarctica2.A2003327.2320 ]. Image courtesy Jacques Descloitres, MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
|
Floods in Ethiopia and Somal
…
| Title |
Floods in Ethiopia and Somalia |
| Description |
Heavy rains pounded down over the Ahmar Mountains and the desert-dry plain to their south and east on April 23 and April 24, 2005. Rivers flowing out of the mountains spread far beyond their banks on April 27, 2005, when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA?s Terra [ http://terra.nasa.gov/ ] satellite captured the top image. In these false-color scenes, water is a deep turquoise against the tan-pink desert. Clouds are light blue. Rivers that were faint spidery shadows on April 11, 2005, lower image, had become wide blue-green stokes that appeared to be hundreds of meters wider than normal on April 27, top. The region shown in this image has been plagued by drought, and that may have contributed to the flooding. Hard, sun-baked ground cannot easily absorb heavy rain, so the water tends to run off, filling depressions and riverbeds. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team and the Goddard Earth Sciences DAAC. |
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Widely Scattered Fires acros
…
| Title |
Widely Scattered Fires across Central Africa |
| Description |
This pair of images from December 11, 2002, shows the diurnal (daily cycle) fire patterns in central Africa. The top image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on the Terra satellite in the morning, while the bottom image was captured by the MODIS on the Aqua satellite in the afternoon. From left to right, this image spans the countries of Nigeria, Cameroon, Chad, and the Central African Republic. At bottom right, a portion of Democratic Republic of Congo is visible. As the day progressed, fire activity (indicated by red dots) increased markedly. The increase is due to both human and environmental factors. Many, if not most, of these fires are set by humans for agricultural purposes: clearing farmland, returning nutrients to the soil, regenerating pasture. People become more active over the course of the day, and fire occurrence increases. Fire activity is also influenced by increasing temperatures and decreasing humidity as the morning progresses to afternoon. This increases the potential for planned fires to get out of control or to burn larger areas than intended. Another interesting difference between the morning and afternoon overpasses is how the relative position of the sun and the satellite during each overpass changes the appearance of the vegetation. Notice that in the Terra overpass, when the light from the sun would have been coming from the southeast, the vegetation at the right of the image appears dark, and the vegetation in the left half of the image appears bright. During the Aqua overpass, the reverse is true: the sun is coming from the southwest, and the vegetation appears bright in the east and dark in the west. This apparent change in surface observations due to change in the relative positions of the sun and the spacecraft is referred to as the bidirectional effect, and scientists must take the effect into consideration when using satellite data to study surface features on Earth. Image courtesy Jacques Descloitres, MODIS Rapid Response Team at NASA GSFC |
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Widely Scattered Fires acros
…
| Title |
Widely Scattered Fires across Central Africa |
| Description |
This pair of images from December 11, 2002, shows the diurnal (daily cycle) fire patterns in central Africa. The top image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on the Terra satellite in the morning, while the bottom image was captured by the MODIS on the Aqua satellite in the afternoon. From left to right, this image spans the countries of Nigeria, Cameroon, Chad, and the Central African Republic. At bottom right, a portion of Democratic Republic of Congo is visible. As the day progressed, fire activity (indicated by red dots) increased markedly. The increase is due to both human and environmental factors. Many, if not most, of these fires are set by humans for agricultural purposes: clearing farmland, returning nutrients to the soil, regenerating pasture. People become more active over the course of the day, and fire occurrence increases. Fire activity is also influenced by increasing temperatures and decreasing humidity as the morning progresses to afternoon. This increases the potential for planned fires to get out of control or to burn larger areas than intended. Another interesting difference between the morning and afternoon overpasses is how the relative position of the sun and the satellite during each overpass changes the appearance of the vegetation. Notice that in the Terra overpass, when the light from the sun would have been coming from the southeast, the vegetation at the right of the image appears dark, and the vegetation in the left half of the image appears bright. During the Aqua overpass, the reverse is true: the sun is coming from the southwest, and the vegetation appears bright in the east and dark in the west. This apparent change in surface observations due to change in the relative positions of the sun and the spacecraft is referred to as the bidirectional effect, and scientists must take the effect into consideration when using satellite data to study surface features on Earth. Image courtesy Jacques Descloitres, MODIS Rapid Response Team at NASA GSFC |
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Odyssey Over Mars
| Title |
Odyssey Over Mars |
| Explanation |
Scroll right and journey [ http://pdsmaps.wr.usgs.gov/maps.html ] for 300 kilometers over Terra Sirenum [ http://www-pdsimage.wr.usgs.gov/PDS/public/mapmaker/ mapmkr.htm ] in the cratered [ http://clasdean.la.asu.edu/news/images/msipix/ ] highlands of southern Mars [ http://www.uapress.arizona.edu/online.bks/mars/ contents.htm ]. The infrared view [ http://photojournal.jpl.nasa.gov/cgi-bin/ PIAGenCatalogPage.pl?PIA03483 ], 32 kilometers wide, was recently recorded by the THEMIS [ http://themis.asu.edu/latest.html ] camera on board the orbiting Mars Odyssey [ http://mars.jpl.nasa.gov/missions/present/ odyssey.html ] spacecraft. Beginning [ http://themis.asu.edu/zoom-ir_day_f1.html ] at the north (left) edge, the scene sweeps across the floor and over the rim of Koval'sky Crater. Continuing [ http://themis.asu.edu/zoom-ir_day_f2.html ] southward [ http://themis.asu.edu/zoom-ir_day_f3.html ] (right) of the crater's rim are lava flows [ http://volcano.und.nodak.edu/vwdocs/planet_volcano/mars/ Overview.html ] exhibiting fractures and numerous smaller impact craters. The infrared [ http://sirtf.caltech.edu/Education/Yellowstone/ gallery.html ] image was made in daylight hours, so sun-facing slopes are still warm and bright while shadowed areas are cool and dark. But rocky [ http://antwrp.gsfc.nasa.gov/apod/ap010721.html ] regions also tend to remain cooler [ http://sirtf.caltech.edu/Education/Zoo/ zoo.html ] and darker than their surroundings, likely corresponding to the dark blotchy terrain along the Koval'sky Crater floor and dark rings of rocky ejecta surrounding some of the smaller craters [ http://wwwflag.wr.usgs.gov/USGSFlag/Space/nomen/mars/ marscrat.html ]. |
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Dust Storms from Africa's Bo
…
nasa, nasanaturalhazards
Once serving as part of the
…
Bodele_TMO2004042
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2004-02-11 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Bodele_TMO2004042 |
|
First Monthly CERES Global L
…
nasa, nasaimageofthedaygalle
…
*NASA Releases Terra's First
…
ceres_monthly_200003
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2000-03-01 |
| creator |
NASA -- Data courtesy CERES instrument team |
| identifier |
ceres_monthly_200003 |
|
Dust over the Arabian Sea: N
…
nasa, nasanaturalhazards
A number of jets of windblow
…
Pakistan_TMO2003061
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-03-02 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Pakistan_TMO2003061 |
|
|
