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Mount Saint Helens
title Mount Saint Helens
description Mount Saint Helens exemplifies how Earth's topographic form can change greatly even within our lifetimes. The mountain is one of several prominent volcanoes of the Cascade Range that stretches from British Columbia, Canada, southward through Washington, Oregon and into northern California. Mount Adams (left background) and Mount Hood (right background) are also seen in this view, which was created entirely from elevation data produced by the Shuttle Radar Topography Mission. Prior to 1980, Mount Saint Helens had a shape roughly similar to other Cascade peaks, a tall, bold, irregular conic form that rose to 9,677 feet (2,950 meters). However, the explosive eruption of May 18, 1980, caused the upper 1,300 feet (400 meters) of the mountain to collapse, slide and spread northward, covering much of the adjacent terrain (lower left), leaving a crater atop the greatly shortened mountain. Subsequent eruptions built a volcanic dome within the crater, and the high rainfall of this area lead to substantial erosion of the poorly consolidated landslide material. Eruptions at Mount Saint Helens subsided in 1986, but renewed volcanic activity here and at other Cascade volcanoes is inevitable. Predicting such eruptions still presents challenges, but migration of magma within these volcanoes often produces distinctive seismic activity and minor but measurable topographic changes that can give warning of a potential eruption. Image credit: NASA/JPL/NGA
3-D Perspective Pasadena, Ca …
Title 3-D Perspective Pasadena, California
Full Description This perspective view shows the western part of the city of Pasadena, California, looking north towards the San Gabriel Mountains. Portions of the cities of Altadena and La Canada, Flintridge are also shown. The image was created from three datasets: the Shuttle Radar Topography Mission (SRTM) supplied the elevation data, Landsat data from November 11, 1986 provided the land surface color (not the sky) and U.S. Geological Survey digital aerial photography provides the image detail. The Rose Bowl, surrounded by a golf course, is the circular feature at the bottom center of the image. The Jet Propulsion Laboratory is the cluster of large buildings north of the Rose Bowl at the base of the mountains. A large landfill, Scholl Canyon, is the smooth area in the lower left corner of the scene. This image shows the power of combining data from different sources to create planning tools to study problems that affect large urban areas. In addition to the well-known earthquake hazards, Southern California is affected by a natural cycle of fire and mudflows. Wildfires strip the mountains of vegetation, increasing the hazards from flooding and mudflows for several years afterwards. Data such as shown on this image can be used to predict both how wildfires will spread over the terrain and also how mudflows will be channeled down the canyons. The Shuttle Radar Topography Mission (SRTM), launched on February 11, 2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission was designed to collect three dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC. Size: 5.8 km (3.6 miles) x 10 km (6.2 miles) Location: 34.16 deg. North lat., 118.16 deg. West lon. Orientation: Looking North Original Data Resolution: SRTM, 30 meters, Landsat,30 meters, Aerial Photo, 3 meters (no vertical exaggeration)
Date 02/16/2000
NASA Center Jet Propulsion Laboratory
Hubble Space Telescope Finds …
Title Hubble Space Telescope Finds Stellar Graveyard
Burst of Star Formation Driv …
Title Burst of Star Formation Drives Bubble in Galaxy's Core
Hubble's Largest Galaxy Port …
Title Hubble's Largest Galaxy Portrait Offers a New High-Definition View
General Information What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Giant galaxies weren?t assembled in a day. Neither was this Hubble Space Telescope image of the face-on spiral galaxy Messier 101 (M101). It is the largest and most detailed photo of a spiral galaxy that has ever been released from Hubble. The galaxy?s portrait is actually composed of 51 individual exposures taken with Hubble's Advanced Camera for Surveys and the Wide Field and Planetary Camera 2 in March 1994, September 1994, June 1999, November 2002, and January 2003. The newly composed image also includes elements from images from ground-based photos.
Hubble Eyes Star Birth in th …
Title Hubble Eyes Star Birth in the Extreme
Hubble Sees Faintest Stars i …
Title Hubble Sees Faintest Stars in a Globular Cluster
Hubble Zooms In on Heart of …
Title Hubble Zooms In on Heart of Mystery Comet
Hubble Zooms In on Heart of …
Title Hubble Zooms In on Heart of Mystery Comet
Holiday Wishes from the Hubb …
Title Holiday Wishes from the Hubble Space Telescope
General Information What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Resembling festive lights on a holiday wreath, this NASA/ESA Hubble Space Telescope image of the nearby spiral galaxy M74 is an iconic reminder of the impending season. Bright knots of glowing gas light up the spiral arms, indicating a rich environment of star formation. M74 is located roughly 32 million light-years away in the direction of the constellation Pisces, the Fish. The image is a composite of Advanced Camera for Surveys data taken in 2003 and 2005.
Hubble Zooms In on Heart of …
Title Hubble Zooms In on Heart of Mystery Comet
Hubble Zooms In on Heart of …
Title Hubble Zooms In on Heart of Mystery Comet
Hubble Sees Faintest Stars i …
Title Hubble Sees Faintest Stars in a Globular Cluster
Hubble Zooms In on Heart of …
Title Hubble Zooms In on Heart of Mystery Comet
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.
New Gullies on Martian Sand …
title New Gullies on Martian Sand Dune
Description One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter (insert MOC2-1212a), encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. Based on earlier observations of other dune fields with gullies, camera-team scientists suspect that, these gullies form by a process other than water fluidization. An image of a dune in Russell Crater, taken by the Mars Orbiter Camera in March 2001, (insert MOC2-1212c) shows how the morphology of the dune's slip face changes with direction: Gullies form on pole-facing slopes (southwest in this case), while normal slip-face avalanche features ("avalanches" in the figure) are seen on the equator-facing slopes (northwest in this case). Most of the dunes that have gullies on them are located in the Hellespontus and Noachis regions, and are frost-covered during the winter. Based on experience in Antarctica and other cold regions on Earth, it is known that snow and ice can be incorporated into dunes during winter. An example is the layering of snow buried in a sand dune in Victoria Valley, Antarctica, seen in a photograph taken by Michael Malin during the austral summer of 1982-1983 (insert MOC2-1212d). Active sand dunes in cold regions such as Antarctica and northern Canada commonly incorporate wintertime snow as new sand avalanches down a slip face and covers the frozen material. A similar process might occur for middle and high latitude dunes on Mars, although in many cases the "snow" would consist mostly of carbon-dioxide frost, with minimal water ice. What would happen to carbon-dioxide frost incorporated into a martian sand dune? On surfaces that receive early and direct sunlight, the sand would heat and the carbon-dioxide frost would sublime over a period of time, undermining the slope and promoting normal sand sliding. On slopes that were initially shaded and later exposed to direct sunlight, heating would be delayed and the carbon dioxide frost would sublime rapidly. This rapid formation of carbon-dioxide gas may act to fluidize overlying sand, causing it to flow rather than avalanche, and thus create a gully. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington. Credit: NASA/JPL/MSSS/ASU
NASA's Aquarius/SAC-D Missio …
nasa, nasaheadquartersflickr …
Gary Lagerloef, Aquarius Pri …
5731306842_763318ecd5_o
mediatype IMAGE
mediatype image
date 2011-05-17
creator NASA
identifier 5731306842_763318ecd5_o
Tree Cover: Image of the Day
nasa, nasaimageofthedaygalle …
Trees are the interface betw …
treecover_combined
mediatype IMAGE
mediatype image
date 2003
creator NASA -- Image by Robert Simmon, based on data provided by Matt Hansen, University of Maryland Global Land Cover Facility
identifier treecover_combined
Tree Cover: Image of the Day
nasa, nasaimageofthedaygalle …
Trees are the interface betw …
treecover_combined
mediatype IMAGE
mediatype image
date 2003
creator NASA -- Image by Robert Simmon, based on data provided by Matt Hansen, University of Maryland Global Land Cover Facility
identifier treecover_combined
Northern Forest Affected by …
nasa, nasaimageofthedaygalle …
823-10827. * Arctic Climate …
forest_tundra_trend_iotd
mediatype IMAGE
mediatype image
date 2003
creator NASA -- (Map adapted from figures provided by Scott Goetz, www.whrc.org/ Woods Hole Research Center )
identifier forest_tundra_trend_iotd
NASA's Aquarius/SAC-D Missio …
nasa, nasaheadquartersflickr …
Gary Lagerloef, left, Aquari …
5731306978_3d8d68be26_o
mediatype IMAGE
mediatype image
date 2011-05-17
creator NASA
identifier 5731306978_3d8d68be26_o
NASA's Aquarius/SAC-D Missio …
nasa, nasaheadquartersflickr …
Gary Lagerloef, right, Aquar …
5731308340_df4f8bbb9c_o
mediatype IMAGE
mediatype image
date 2011-05-17
creator NASA
identifier 5731308340_df4f8bbb9c_o
NASA's Aquarius/SAC-D Missio …
nasa, nasaheadquartersflickr …
Seated from left, Eric Linds …
5731307090_0281f263eb_o
mediatype IMAGE
mediatype image
date 2011-05-17
creator NASA
identifier 5731307090_0281f263eb_o
Heat Wave in North America: …
nasa, nasanaturalhazards
Scorching summer sun, burnin …
nalstanom_tmo_2006193
mediatype IMAGE
mediatype image
date 2006-07-19
creator NASA -- NASA Image Of The Day
identifier nalstanom_tmo_2006193
Heat Wave in North America: …
nasa, nasanaturalhazards
Scorching summer sun, burnin …
nalstanom_tmo_2006193
mediatype IMAGE
mediatype image
date 2006-07-19
creator NASA -- NASA Image Of The Day
identifier nalstanom_tmo_2006193
NASA's Aquarius/SAC-D Missio …
nasa, nasaheadquartersflickr …
A reporter asks a question t …
5730757683_7a546c4edd_o
mediatype IMAGE
mediatype image
date 2011-05-17
creator NASA
identifier 5730757683_7a546c4edd_o
MISR Sees a Cloud's Reflecti …
nasa, nasaimageofthedaygalle …
MISR images of the southeast …
misr_canada
mediatype IMAGE
mediatype image
date 2000-03-06
creator NASA -- Image by NASA/GSFC/JPL, MISR Science Team
identifier misr_canada
Oppressive Heat Wave Moves a …
nasa, nasaimageofthedaygalle …
The last two weeks of July a …
heatwave_cer_200607
mediatype IMAGE
mediatype image
date 2006-08-06
creator NASA -- NASA images by Takmeng Wong with the asd-www.larc.nasa.gov/ceres/ CERES Science Team at NASA Langley Research Center.
identifier heatwave_cer_200607
Oppressive Heat Wave Moves a …
nasa, nasaimageofthedaygalle …
The last two weeks of July a …
heatwave_cer_200607
mediatype IMAGE
mediatype image
date 2006-08-06
creator NASA -- NASA images by Takmeng Wong with the asd-www.larc.nasa.gov/ceres/ CERES Science Team at NASA Langley Research Center.
identifier heatwave_cer_200607
Smoke Signals from the Alask …
nasa, nasaimageofthedaygalle …
Large, lightning-induced fir …
PIA04363
mediatype IMAGE
mediatype image
date 2004-06-30
creator NASA -- Image courtesy NASA/GSFC/LaRC/JPL, www-misr.jpl.nasa.gov/ MISR Team and Dominic Mazzoni (JPL). Text by Clare Averill (Raytheon/JPL).
identifier PIA04363
Western United States and So …
nasa, nasaimageofthedaygalle …
This natural-color image fro …
PIA04330
mediatype IMAGE
mediatype image
date 2003
creator NASA -- Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. mailto:jknighton@clear-light.com Jim Knighton of Clear Light Image Products produced the image mosaic. Please note that the high-resolution TIF image is provided here at a pixel resolution of approximately 1.1 kilometers, but is available from the producer at a resolution of 278 meters. Text by Clare Averill (Acro Service Corporation/JPL).
identifier PIA04330
Anaglyph, North America
PIA03378
Sol (our sun)
C-Band Interferometric Radar
Title Anaglyph, North America
Original Caption Released with Image This anaglyph (stereoscopic view) of North America was generated with data from the Shuttle Radar Topography Mission (SRTM). It is best viewed at or near full resolution with anaglyph glasses. For this broad view the resolution of the data was first reduced to 30 arcseconds (about 928 meters north-south and 736 meters east-west in central North America), matching the best previously existing global digital topographic data set called GTOPO30. The data were then resampled to a Mercator projection with approximately square pixels (about one kilometer, or 0.6 miles, on each side). Even at this decreased resolution the variety of landforms comprising the North American continent is readily apparent. Active tectonics (structural deformation of the Earth's crust) along and near the Pacific North American plate boundary creates the great topographic relief seen along the Pacific coast. Earth's crustal plates converge in southern Mexico and in the northwest United States, melting the crust and producing volcanic cones. Along the California coast, the plates are sliding laterally past each other, producing a pattern of slices within the San Andreas fault system. And, where the plates are diverging, the crust appears torn apart as one huge tear along the Gulf of California (northwest Mexico), and as the several fractures comprising the Basin and Range province (in and around Nevada). Across the Great Plains, erosional patterns dominate, with stream channels surrounding and penetrating the remnants of older smooth slopes east of the Rocky Mountains. This same erosion process is exposing the bedrock structural patterns of the Black Hills in South Dakota and the Ozark Mountains in Arkansas. Lateral erosion and sediment deposition by the Mississippi River has produced the flatlands of the lower Mississippi Valley and the Mississippi Delta. To the north, evidence of the glaciers of the last ice age is widely found, particularly east of the Canadian Rocky Mountains and around the Great Lakes. From northeastern British Columbia, across Alberta, Saskatchewan, and Manitoba to North Dakota and Minnesota, huge striations clearly show the flow pattern of the glaciers. And southwest of Lakes Michigan, Huron, and Erie, arcing ridges of sediment, called terminal moraines, show where glaciers dumped sediment at their melting ends. In eastern Canada, New York, and New England, the terrain has been scoured by glaciers, and eroded by streams, particularly along fractures in the bedrock. In Labrador and Quebec, the Mistastin, Manicougan, and Clearwater Lakes meteor impact craters can also be seen. Further south, narrow curving ridges of upturned and eroded layered rocks form most of the Appalachian Mountains. In contrast, around the Caribbean Sea region (Yucatan, Florida, and the Bahamas), flat-lying, stable limestone platforms are common, while the most eastern islands of the Caribbean include active volcanoes along another convergence zone of tectonic plates. This, anaglyph was created by deriving a shaded relief image from the SRTM data, draping it back over the SRTM elevation model, and then generating two differing perspectives, one for each eye. Illumination is from the north (top). When viewed through special glasses, the anaglyph is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. Elevation data used in this image were acquired by the SRTM aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Location: 15 to 60 degrees North latitude, 50 to 130 degrees West longitude Orientation: North toward the top, Mercator projection Image Data: Shaded SRTM elevation model Original Data Resolution: SRTM 1 arcsecond (about 30 meters or 98 feet) Date Acquired: February 2000
Shaded Relief with Height as …
PIA03377
Sol (our sun)
C-Band Interferometric Radar
Title Shaded Relief with Height as Color, North America
Original Caption Released with Image This image of North America was generated with data from the Shuttle Radar Topography Mission (SRTM). For this broad view the resolution of the data was first reduced to 30 arcseconds (about 928 meters north-south and 736 meters east-west in central North America), matching the best previously existing global digital topographic data set called GTOPO30. The data were then resampled to a Mercator projection with approximately square pixels (about one kilometer, or 0.6 miles, on each side). Even at this decreased resolution the variety of landforms comprising the North American continent is readily apparent. Active tectonics (structural deformation of the Earth's crust) along and near the Pacific -- North American plate boundary creates the great topographic relief seen along the Pacific coast. Earth's crustal plates converge in southern Mexico and in the northwest United States, melting the crust and producing volcanic cones. Along the California coast, the plates are sliding laterally past each other, producing a pattern of slices within the San Andreas fault system. And, where the plates are diverging, the crust appears torn apart as one huge tear along the Gulf of California (northwest Mexico), and as the several fractures comprising the Basin and Range province (in and around Nevada). Across the Great Plains, erosional patterns dominate, with streams channels surrounding and penetrating the remnants of older smooth slopes east of the Rocky Mountains. This same erosion process is exposing the bedrock structural patterns of the Black Hills in South Dakota and the Ozark Mountains in Arkansas. Lateral erosion and sediment deposition by the Mississippi River has produced the flatlands of the lower Mississippi Valley and the Mississippi Delta. To the north, evidence of the glaciers of the last ice age is widely found, particularly east of the Canadian Rocky Mountains and around the Great Lakes. From northeastern British Columbia, across Alberta, Saskatchewan, and Manitoba to North Dakota and Minnesota, huge striations clearly show the flow pattern of the glaciers. And southwest of Lakes Michigan, Huron, and Erie, arcing ridges of sediment, called terminal moraines, show where glaciers dumped sediment at their melting ends. In eastern Canada, New York, and New England, the terrain has been scoured by glaciers, and eroded by streams, particularly along fractures in the bedrock. In Labrador and Quebec, the Mistastin, Manicougan, and Clearwater Lakes meteor impact craters can also be seen. Further south, narrow curving ridges of upturned and eroded layered rocks form most of the Appalachian Mountains. In contrast, around the Caribbean Sea region (Yucatan, Florida, and the Bahamas), flat-lying, stable limestone platforms are common, while the most eastern islands of the Caribbean include active volcanoes along another convergence zone of tectonic plates. Two visualization methods were combined to produce the image: shading and color coding of, topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Location: 15 to 60 degrees North latitude, 50 to 130 degrees West longitude Orientation: North toward the top, Mercator projection Image Data: shaded and colored SRTM elevation model Original Data Resolution: SRTM 1 arcsecond (about 30 meters or 98 feet) Date Acquired: February 2000
MISR View of Georgian Bay, O …
PIA02615
Sol (our sun)
Multi-angle Imaging SpectroR …
Title MISR View of Georgian Bay, Ontario, Canada
Original Caption Released with Image MISR images of the southeast portion of Georgian Bay in Ontario, Canada, acquired on March 6, 2000, during Terra orbit 1155. The color image is from the nadir (vertical) camera, and highlights a cloud to the southwest of Christian Island. In this view, the shadow cast by the cloud on the water is visible just north of the cloud itself. Bright areas in the image are either cloud or ice, an example of the latter is the frozen Lake Simcoe. The eight monochrome images are red band data from the off-nadir cameras. Starting with the one in the upper right and moving counterclockwise, the images progress from the most forward-viewing to the most aftward-viewing camera. Thus, the top (bottom) row of monochrome images are views acquired forward (aftward) of vertical. The apparent displacement of the cloud from south to north as the view progresses from forward to aftward is primarily a geometric parallax effect due to the cloud's elevation above the surface. In each image in the top row, a fainter feature with the same shape as the cloud is visible within Georgian Bay. The feature and the cloud itself approach one another as the view angle becomes less oblique. The feature is present only in the water, and disappears over the land surface of Christian Island. What is it? We are observing reflections of the cloud in the water. Their positions are dictated by the law of reflection, which states that the angle relative to the vertical of the reflected rays is the same as the angle of the incident rays. Therefore, the apparent location of a reflection relative to the cloud changes as a function of camera view angle. Unlike water, land does not act as a good mirror. Also, in the aftward views the reflections are less visible because they are blocked by the southern extension of the cloud. Reflections of this sort are not visible in conventional vertical imagery because in that case they lie directly underneath the cloud, and are consequently obscured. 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. For more information: http://www-misr.jpl.nasa.gov
Space Radar Image of Prince …
PIA01702
Sol (our sun)
Title Space Radar Image of Prince Albert, Canada
New Gullies on Martian Sand …
PIA04290
Sol (our sun)
Mars Orbiter Camera
Title New Gullies on Martian Sand Dune
Original Caption Released with Image ), encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. Based on earlier observations of other dune fields with gullies, camera-team scientists suspect that these gullies form by a process other than water fluidization. An image of a dune in Russell Crater, taken by the Mars Orbiter Camera in March 2001, (figure 3) shows how the morphology of the dune's slip face changes with direction: Gullies form on pole-facing slopes (southwest in this case), while normal slip-face avalanche features ("avalanches" in the figure) are seen on the equator-facing slopes (northwest in this case). Most of the dunes that have gullies on them are located in the Hellespontus and Noachis regions, and are frost-covered during the winter. Based on experience in Antarctica and other cold regions on Earth, it is known that snow and ice can be incorporated into dunes during winter. An example is the layering of snow buried in a sand dune in Victoria Valley, Antarctica, seen in a photograph taken by Michael Malin during the austral summer of 1982-1983 (figure 4). Active sand dunes in cold regions such as Antarctica and northern Canada commonly incorporate wintertime snow as new sand avalanches down a slip face and covers the frozen material. A similar process might occur for middle and high latitude dunes on Mars, although in many cases the "snow" would consist mostly of carbon-dioxide frost, with minimal water ice. What would happen to carbon-dioxide frost incorporated into a martian sand dune? On surfaces that receive early and direct sunlight, the sand would heat and the carbon-dioxide frost would sublime over a period of time, undermining the slope and promoting normal sand sliding. On slopes that were initially shaded and later exposed to direct sunlight, heating would be delayed and the carbon dioxide frost would sublime rapidly. This rapid formation of carbon-dioxide gas may act to fluidize overlying sand, causing it to flow rather than avalanche, and thus create a gully. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington., One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images (figure 1) from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter (figure 2
New Gullies on Martian Sand …
PIA04290
Sol (our sun)
Mars Orbiter Camera
Title New Gullies on Martian Sand Dune
Original Caption Released with Image ), encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. Based on earlier observations of other dune fields with gullies, camera-team scientists suspect that these gullies form by a process other than water fluidization. An image of a dune in Russell Crater, taken by the Mars Orbiter Camera in March 2001, (figure 3) shows how the morphology of the dune's slip face changes with direction: Gullies form on pole-facing slopes (southwest in this case), while normal slip-face avalanche features ("avalanches" in the figure) are seen on the equator-facing slopes (northwest in this case). Most of the dunes that have gullies on them are located in the Hellespontus and Noachis regions, and are frost-covered during the winter. Based on experience in Antarctica and other cold regions on Earth, it is known that snow and ice can be incorporated into dunes during winter. An example is the layering of snow buried in a sand dune in Victoria Valley, Antarctica, seen in a photograph taken by Michael Malin during the austral summer of 1982-1983 (figure 4). Active sand dunes in cold regions such as Antarctica and northern Canada commonly incorporate wintertime snow as new sand avalanches down a slip face and covers the frozen material. A similar process might occur for middle and high latitude dunes on Mars, although in many cases the "snow" would consist mostly of carbon-dioxide frost, with minimal water ice. What would happen to carbon-dioxide frost incorporated into a martian sand dune? On surfaces that receive early and direct sunlight, the sand would heat and the carbon-dioxide frost would sublime over a period of time, undermining the slope and promoting normal sand sliding. On slopes that were initially shaded and later exposed to direct sunlight, heating would be delayed and the carbon dioxide frost would sublime rapidly. This rapid formation of carbon-dioxide gas may act to fluidize overlying sand, causing it to flow rather than avalanche, and thus create a gully. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington., One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images (figure 1) from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter (figure 2
New Gullies on Martian Sand …
PIA04290
Sol (our sun)
Mars Orbiter Camera
Title New Gullies on Martian Sand Dune
Original Caption Released with Image ), encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. Based on earlier observations of other dune fields with gullies, camera-team scientists suspect that these gullies form by a process other than water fluidization. An image of a dune in Russell Crater, taken by the Mars Orbiter Camera in March 2001, (figure 3) shows how the morphology of the dune's slip face changes with direction: Gullies form on pole-facing slopes (southwest in this case), while normal slip-face avalanche features ("avalanches" in the figure) are seen on the equator-facing slopes (northwest in this case). Most of the dunes that have gullies on them are located in the Hellespontus and Noachis regions, and are frost-covered during the winter. Based on experience in Antarctica and other cold regions on Earth, it is known that snow and ice can be incorporated into dunes during winter. An example is the layering of snow buried in a sand dune in Victoria Valley, Antarctica, seen in a photograph taken by Michael Malin during the austral summer of 1982-1983 (figure 4). Active sand dunes in cold regions such as Antarctica and northern Canada commonly incorporate wintertime snow as new sand avalanches down a slip face and covers the frozen material. A similar process might occur for middle and high latitude dunes on Mars, although in many cases the "snow" would consist mostly of carbon-dioxide frost, with minimal water ice. What would happen to carbon-dioxide frost incorporated into a martian sand dune? On surfaces that receive early and direct sunlight, the sand would heat and the carbon-dioxide frost would sublime over a period of time, undermining the slope and promoting normal sand sliding. On slopes that were initially shaded and later exposed to direct sunlight, heating would be delayed and the carbon dioxide frost would sublime rapidly. This rapid formation of carbon-dioxide gas may act to fluidize overlying sand, causing it to flow rather than avalanche, and thus create a gully. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington., One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images (figure 1) from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter (figure 2
New Gullies on Martian Sand …
PIA04290
Sol (our sun)
Mars Orbiter Camera
Title New Gullies on Martian Sand Dune
Original Caption Released with Image ), encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. Based on earlier observations of other dune fields with gullies, camera-team scientists suspect that these gullies form by a process other than water fluidization. An image of a dune in Russell Crater, taken by the Mars Orbiter Camera in March 2001, (figure 3) shows how the morphology of the dune's slip face changes with direction: Gullies form on pole-facing slopes (southwest in this case), while normal slip-face avalanche features ("avalanches" in the figure) are seen on the equator-facing slopes (northwest in this case). Most of the dunes that have gullies on them are located in the Hellespontus and Noachis regions, and are frost-covered during the winter. Based on experience in Antarctica and other cold regions on Earth, it is known that snow and ice can be incorporated into dunes during winter. An example is the layering of snow buried in a sand dune in Victoria Valley, Antarctica, seen in a photograph taken by Michael Malin during the austral summer of 1982-1983 (figure 4). Active sand dunes in cold regions such as Antarctica and northern Canada commonly incorporate wintertime snow as new sand avalanches down a slip face and covers the frozen material. A similar process might occur for middle and high latitude dunes on Mars, although in many cases the "snow" would consist mostly of carbon-dioxide frost, with minimal water ice. What would happen to carbon-dioxide frost incorporated into a martian sand dune? On surfaces that receive early and direct sunlight, the sand would heat and the carbon-dioxide frost would sublime over a period of time, undermining the slope and promoting normal sand sliding. On slopes that were initially shaded and later exposed to direct sunlight, heating would be delayed and the carbon dioxide frost would sublime rapidly. This rapid formation of carbon-dioxide gas may act to fluidize overlying sand, causing it to flow rather than avalanche, and thus create a gully. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington., One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images (figure 1) from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter (figure 2
New Gullies on Martian Sand …
PIA04290
Sol (our sun)
Mars Orbiter Camera
Title New Gullies on Martian Sand Dune
Original Caption Released with Image ), encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. Based on earlier observations of other dune fields with gullies, camera-team scientists suspect that these gullies form by a process other than water fluidization. An image of a dune in Russell Crater, taken by the Mars Orbiter Camera in March 2001, (figure 3) shows how the morphology of the dune's slip face changes with direction: Gullies form on pole-facing slopes (southwest in this case), while normal slip-face avalanche features ("avalanches" in the figure) are seen on the equator-facing slopes (northwest in this case). Most of the dunes that have gullies on them are located in the Hellespontus and Noachis regions, and are frost-covered during the winter. Based on experience in Antarctica and other cold regions on Earth, it is known that snow and ice can be incorporated into dunes during winter. An example is the layering of snow buried in a sand dune in Victoria Valley, Antarctica, seen in a photograph taken by Michael Malin during the austral summer of 1982-1983 (figure 4). Active sand dunes in cold regions such as Antarctica and northern Canada commonly incorporate wintertime snow as new sand avalanches down a slip face and covers the frozen material. A similar process might occur for middle and high latitude dunes on Mars, although in many cases the "snow" would consist mostly of carbon-dioxide frost, with minimal water ice. What would happen to carbon-dioxide frost incorporated into a martian sand dune? On surfaces that receive early and direct sunlight, the sand would heat and the carbon-dioxide frost would sublime over a period of time, undermining the slope and promoting normal sand sliding. On slopes that were initially shaded and later exposed to direct sunlight, heating would be delayed and the carbon dioxide frost would sublime rapidly. This rapid formation of carbon-dioxide gas may act to fluidize overlying sand, causing it to flow rather than avalanche, and thus create a gully. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington., One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images (figure 1) from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter (figure 2
Multi-angle Images of Hudson …
PIA02603
Sol (our sun)
Multi-angle Imaging SpectroR …
Title Multi-angle Images of Hudson Bay and James Bay, Canada, 24 February 2000
Original Caption Released with Image At left is a true-color image from the downward-looking (nadir)camera on the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite. The false-color image at right is a composite of red band data taken by the MISR forward 45.6-degree, nadir, and aftward 45.6-degree cameras, displayed in blue, green, and red colors, respectively. Color variations in the left image highlight spectral (true-color) differences, whereas those in the right image highlight differences in angular reflectance properties. The purple areas in the right image are low cloud, and light blue at the edge of the bay is due to increased forward scattering by the fast (smooth)ice. The orange areas are rougher ice, which scatters more light in the backward direction. This example illustrates how multi-angle viewing can distinguish physical structures and textures. Data for all channels are presented in a Space Oblique Mercator map projection to facilitate their co-registration. The images are about 400 km (250 miles) wide with a spatial resolution of about 275 meters (300 yards). North is toward the top. 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.
Green Summer and Icy Winter …
PIA02645
Sol (our sun)
Multi-angle Imaging SpectroR …
Title Green Summer and Icy Winter in James Bay
Original Caption Released with Image One year ago, in late February 2000, MISR began acquiring Earth imagery. Its "first light" images showed a frozen James Bay in the Ontario-Quebec region of Canada. These more recent nadir-camera views of the same area illuminate stark contrasts between summer and winter. The left-hand image was acquired on August 9, 2000 (Terra orbit 3427), and the right-hand image is from January 16, 2001 (Terra orbit 5757). James Bay lies at the southern end of Hudson Bay. It is named for the English explorer Thomas James, who first explored the area in 1631 while searching for the Northwest Passage. Visible in these images are some of the many rivers that flow into the bay, starting at the southern tip and moving clockwise on the western side are the Harricana, Moose, Albany, and Attawapiskat. The latter enters the bay just to the west of the large, crescent-shaped Akimiski Island. 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.
Pasadena, California Anaglyp …
PIA02721
Sol (our sun)
C-Band Interferometric Radar
Title Pasadena, California Anaglyph with Aerial Photo Overlay
Original Caption Released with Image This anaglyph shows NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. Red-blue glasses are required to see the 3-D effect. The surrounding residential areas of La Canada-Flintridge (to the left) and Altadena/Pasadena (to the right) are also shown. JPL is located at the base of the San Gabriel Mountains, an actively growing mountain range, seen towards the top of the image. The large canyon coming out of the mountains (top to bottom of image) is the Arroyo Seco, which is a major drainage channel for the mountains. Sand and gravel removal operations in the lower part of the arroyo (bottom of image) are removing debris brought down by flood and mudflow events. Old landslide scars (lobe-shaped features) are seen in the arroyo, evidence that living near steep canyon slopes in tectonically active areas can be hazardous. The data can also be utilized by recreational users such as hikers enjoying the natural beauty of these rugged mountains. This anaglyph was generated using topographic data from the Shuttle Radar Topography Mission to create two differing perspectives of a single image, one perspective for each eye. The detailed aerial image was provided by U. S. Geological Survey digital orthophotography. Each point in the image is shifted slightly, depending on its elevation. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC. Size: 2.2 km (1.4 miles) x 2.4 km (1.49 miles) Location: 34.16 deg. North lat., 118.16 deg. West lon. Orientation: looking straight down at land Original Data Resolution: SRTM, 30 meters, Aerial Photo, 3 meters. Date Acquired: February 16, 2000 Image: NASA/JPL/NIMA
Smoke Soars to Stratospheric …
PIA04365
Sol (our sun)
Multi-angle Imaging SpectroR …
Title Smoke Soars to Stratospheric Heights
Original Caption Released with Image A new look at smoke from the Chisholm forest fire, which ignited on May 23, 2001 about 160 kilometers north of Edmonton in Alberta, Canada, provides confirming evidence that dense smoke can reach the upper troposphere and lower stratosphere. Scientists have postulated a link between fires in northern forests and the observed enhancements in stratospheric aerosols, but it is difficult to measure smoke aerosol heights directly. Here, height information for the Chisholm fire was retrieved using stereoscopic processing of data from multiple Multi-angle Imaging SpectroRadiometer (MISR) cameras. These images were acquired on May 29, when the severity of the fire had begun to stabilize after a cold front and strong low-level winds caused rapid spread of flame and an eruption of large-scale convection on May 28. This dramatic event was studied in detail by M. Fromm and R. Servranckx, "Transport of forest fire smoke above the tropopause by supercell convection", Geophys. Res. Lett., vol. 30, no. 10 (2003). The two left-hand images are natural color views from MISR's nadir and 60° forward viewing cameras in which a pall of yellowish smoke is apparent both above the surface and above clouds in the top portion of the images. This area is near the junction of Canada's Keewatin region and Northwest Territory, and about 1200 km northward of the originalfire location. Lake Athabasca is at the lower left. The second panel from the right is MISR's standard stereo height product (derived from the nadir and the two 26° cameras), while the right-hand panel is a specially-generated product using MISR's 46° and 60° forward-pointing cameras. Because the smoke appears thicker at the oblique view angles, better areal coverage is obtained and the retrievals are less sensitive to the underlying cloud deck. The southern portion of the smoke cloud is at an altitude of about 3.5 km, however, the smoke further to the north has risen above the tropopause (which is at about 11 km altitude) and intruded into the lower stratosphere. These measurements indicate that smoke reaches heights of about 12-13 kilometers above sea level. The height fields pictured here are uncorrected for wind effects, wind-corrected heights (which have higher accuracy but sparser spatial coverage) for this smoke pall are about 0.5 km higher. The Multiangle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82° north and 82° south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 7695. The panels cover an area of 380 kilometers x 1137 kilometers, and utilize data from blocks 36 to 43 within World Reference System-2 path 40. 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.
Anaglyph of Perspective View …
PIA02731
Sol (our sun)
C-Band Interferometric Radar
Title Anaglyph of Perspective View with Aerial Photo Overlay Pasadena, California
Original Caption Released with Image This anaglyph is a perspective view that shows the western part of the city of Pasadena, California, looking north toward the San Gabriel Mountains. Red-blue glasses are required to see the 3-D effect. Portions of the cities of Altadena and La Canada-Flintridge are also shown. The image was created from two datasets: the Shuttle Radar Topography Mission (SRTM) supplied the elevation data and U. S. Geological Survey digital aerial photography provided the image detail. The Jet Propulsion Laboratory is the cluster of large buildings left of center, at the base of the mountains. This image shows the power of combining data from different sources to create planning tools to study problems that affect large urban areas. In addition to the well-known earthquake hazards, Southern California is affected by a natural cycle of fire and mudflows. Wildfires can strip the mountains of vegetation, increasing the hazards from flooding and mudflows. Data shown in this image can be used to predict both how wildfires spread over the terrain and how mudflows are channeled down the canyons. This anaglyph was generated using topographic data from the Shuttle Radar Topography Mission to create two differing perspectives of a single image, one perspective for each eye. Each point in the image is shifted slightly, depending on its elevation. When viewed through special glasses, the result is a view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. The Shuttle Radar Topography Mission (SRTM), launched on February 11, 2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC. Size: 5.8 km (3.6 miles) x 10 km (6.2 miles) Location: 34.16 deg. North lat., 118.16 deg. West lon. Orientation: Looking North Original Data Resolution: SRTM, 30 m, aerial photo, 3 m, no vertical exaggeration Date Acquired: February 16, 2000 Image: NASA/JPL/NIMA
Natural Color Mosaic of Nort …
PIA04361
Sol (our sun)
C-Band Interferometric Radar …
Title Natural Color Mosaic of North America
Original Caption Released with Image This natural-color image combines cloud-free data from over 500 Multi-angle Imaging SpectroRadiometer (MISR) orbits with shaded relief Digital Terrain Elevation models from the Shuttle Radar Topography Mission (SRTM) and other sources. An astonishing diversity of geological features, ecological systems and human landscapes across North America is indicated within the image, which spans from 56N, 136W at the upper left to 16N 48W at lower right. In addition to the contiguous United States, the scene spans from British Columbia in the northwest to Newfoundland in the northeast, and extends eastward to the lonely Bermuda Islands and southward to the Bahamas, Cuba and Mexico. Draped in green, the eastern and central United States and Canada contrast with the vibrant geology that is laid bare across the arid portions of the southwestern United States and central Mexico. Along Mexico's east coast, the lush vegetation to the east of the Sierra Madre mountain range indicates the orographic rainfall gradient along this subtropical-tropical coast. In the high Rocky Mountains and in British Columbia's Coast Range, many peaks remain snow-covered year-round. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 north and 82 south latitude. This data product was generated from a portion of the imagery acquired during years 2000 - 2004. The image is displayed in an Albers Conic Equal Area projection with the projection center at 36 North, 92 West. 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.
Mount Saint Helens, Washingt …
PIA06668
Sol (our sun)
C-Band Imaging Radar, X-Band …
Title Mount Saint Helens, Washington, USA, SRTM Perspective: Shaded Relief and Colored Height
Original Caption Released with Image (about 100 miles) Location: 46.2 degrees North latitude, 122.2 degrees West longitude Orientation: View Southeast Image Data: Shaded and colored SRTM elevation model Date Acquired: February 2000, Mount Saint Helens is a prime example of how Earth's topographic form can greatly change even within our lifetimes. The mountain is one of several prominent volcanoes of the Cascade Range that stretches from British Columbia, Canada, southward through Washington, Oregon, and into northern California. Mount Adams (left background) and Mount Hood (right background) are also seen in this view, which was created entirely from elevation data produced by the Shuttle Radar Topography Mission. Prior to 1980, Mount Saint Helens had a shape roughly similar to other Cascade peaks, a tall, bold, irregular conic form that rose to 2950 meters (9677 feet). However, the explosive eruption of May 18, 1980, caused the upper 400 meters (1300 feet) of the mountain to collapse, slide, and spread northward, covering much of the adjacent terrain (lower left), leaving a crater atop the greatly shortened mountain. Subsequent eruptions built a volcanic dome within the crater, and the high rainfall of this area lead to substantial erosion of the poorly consolidated landslide material. Eruptions at Mount Saint Helens subsided in 1986, but renewed volcanic activity here and at other Cascade volcanoes is inevitable. Predicting such eruptions still presents challenges, but migration of magma within these volcanoes often produces distinctive seismic activity and minor but measurable topographic changes that can give warning of a potential eruption. Three visualization methods were combined to produce this image: shading of topographic slopes, color coding of topographic height, and then projection into a perspective view. The shade image was derived by computing topographic slope in the northeast-southwest (left to right) direction, so that northeast slopes appear bright and southwest slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. The perspective view simulates the geometry of the surface as it would be viewed on a clear day. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's NASA's Science Mission Directorate, Washington, D.C. Size: View distance about 150 km
Smoke Signals from the Alask …
PIA04363
Sol (our sun)
Multi-angle Imaging SpectroR …
Title Smoke Signals from the Alaska and Yukon Fires
Original Caption Released with Image . Some of the smoke from these fires was detected as far away as New Hampshire. These visualizations were captured on June 30th by the Multi-angle Imaging SpectroRadiometer (MISR) on NASA's Terra spacecraft. Here, MISR distinguishes clouds from smoke and retrieves heights and optical depths for the smoke -- information which will help to improve models of how smoke aerosols are transported. The images cover an area extending from the Mackenzie Bay in northwest Canada, through the Alaskan Interior and along the Alaska-Yukon border, south to the Wrangell Mountains. The first panel in the series is a natural-color image from MISR's 60° forward viewing camera. Smoke plumes notable along the right-hand edge are situated southwest of the Peel River in the Yukon Territory, and plumes extending west from the left-hand edge are situated in the vicinity of the Yukon River and the town of Eagle at the Alaska-Canada border. In the lower portion of the image, thick smoke obscures the Wrangell Mountain range. The next panel in the series is a stereoscopic height field, in which topography, smoke plumes and clouds are all being detected. Analysis indicates that most of the smoke and many low clouds are situated at heights between about 1 and 4 kilometers above the surface, while a few high clouds attained much greater altitudes. The third panel from the left is a smoke mask, in which the image is classified as either non-smoke, or as smoke with low confidence (lc) or high confidence (hc), represented by the blue, red and green pixels, respectively. Many of the actual smoke "plumes" were identified as high-confidence smoke, including parts of plumes in the Peel River region (upper right) and Yukon River/Alaska-Canada border region (left-hand edge). This smoke mask is produced by a computerized "machine-learning" classifier which detects smoke by examining the spectral, textural, and angular features in the radiances from three oblique-viewing MISR cameras. Ultimately, the classifier will be trained to identify plume-like shapes, thus making it possible to automatically isolate plume heights from the stereo product. The right-hand panel displays MISR's aerosol optical depth retrieval, in which the brightness and contrast changes of the surface at different view angles are used to measure the attenuation of sunlight as it passes through a column of the atmosphere. Increasing amounts of smoke aerosol appear as green, yellow, orange and red pixels, and clearer skies are indicated by blue pixels. Areas where the aerosol optical depth could not be retrieved, either because the smoke was too thick to see the surface contrast or because the presence of clouds precluded a retrieval, are shown in dark gray. 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 non-animated data products were generated from a portion of the imagery acquired, Large lightning-induced fires were active in Alaska and the Yukon Territory from mid-June to mid-July, 2004. Thick smoke particles filled the air during these fires, prompting Alaskan officials to issue air quality warnings [ http://airnow.gov/ ], during Terra orbits 24123. The still panels cover an area of about 400 kilometers 898 kilometers, and use data from blocks 35 to 41 within World Reference System-2 path 64. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., 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.
Western United States and So …
PIA04330
Sol (our sun)
Multi-angle Imaging SpectroR …
Title Western United States and Southwestern Canada
Original Caption Released with Image This natural-color image from the Multi-angle Imaging SpectroRadiometer (MISR) captures the beauty of the western United States and Canada. Data from 45 swaths from MISR's vertical-viewing (nadir) camera were combined to create this cloud-free mosaic. The image extends from 48° N 128° W in the northwest, to 32°N, 104° W in the southeast, and has been draped over a shaded relief Digital Terrain Elevation Model from the United States Geological Survey. The image area includes much of British Columbia, Alberta and Saskatchewan in the north, and extends southward to California, Arizona and New Mexico. The snow-capped Rocky Mountains are a prominent feature extending through British Columbia, Montana, Wyoming, Colorado and New Mexico. Many major rivers originate in the Columbia Plateau region of Washington, Oregon and Idaho. The Colorado Plateau region is characterized by the vibrant red-colored rocks of the Painted Desert in Utah and Arizona, and in New Mexico, White Sands National Park is the large white feature in the Southeast corner of the image with the Malpais lava flow just to its North. The southwest is dominated by the Mojave Desert of California and Nevada, California's San Joaquin Valley, the Los Angeles basin and the Pacific Ocean. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. This data product was generated from a portion of the imagery acquired during 2000-2002. The panels utilize data from blocks 45 to 65 within World Reference System-2 paths 31 to 53. 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.
Stereo Pair, Pasadena, Calif …
PIA02737
Sol (our sun)
C-Band Interferometric Radar …
Title Stereo Pair, Pasadena, California
Original Caption Released with Image This stereoscopic image pair is a perspective view that shows the western part of the city of Pasadena, California, looking north toward the San Gabriel Mountains. Portions of the cities of Altadena and La Canada Flintridge are also shown. The cluster of large buildings left of center, at the base of the mountains, is the Jet Propulsion Laboratory. This image shows the power of combining data from different sources to create planning tools to study problems that affect large urban areas. In addition to the well-known earthquake hazards, Southern California is affected by a natural cycle of fire and mudflows. Data shown in this image can be used to predict both how wildfires spread over the terrain and how mudflows are channeled down the canyons. The image was created from three datasets: the Shuttle Radar Topography Mission (SRTM) supplied the elevation, U. S. Geological Survey digital aerial photography provided the image detail, and the Landsat Thematic Mapper provided the color. The United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota, provided the Landsat data and the aerial photography. The image can be viewed in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing), or by downloading and printing the image pair, and viewing them with a stereoscope. The Shuttle Radar Topography Mission (SRTM), launched on February 11, 2000, used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI)space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC. Size: 3.4 km (2.1 miles) width x 7.0 km (4.4 miles) depth Location: 34.16 deg. North lat., 118.16 deg. West lon. Orientation: Looking North Original Data Resolution: SRTM and Landsat, 30 m, aerial photo, 3 m, no vertical exaggeration Date Acquired: February 16, 2000 (SRTM), July 3, 1985 (Landsat) Image: NASA/JPL/NIMA
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