|
|
ICESat Cloud Walls (south to
…
| Title |
ICESat Cloud Walls (south to north spiral camera path) |
| Abstract |
This is an animation showing data from ICESat's Geoscience Laser Altimeter System (GLAS). Cloud data can be seen over about 15 orbits on October 6, 2003. The data are initially laid out in the order that is was collected followed by continued movement around the scene. This version of the animation starts at the south pole and spirals slowly up to the north pole. |
| Completed |
2004-10-07 |
|
ICESat Cloud Walls (south to
…
| Title |
ICESat Cloud Walls (south to north spiral camera path) |
| Abstract |
This is an animation showing data from ICESat's Geoscience Laser Altimeter System (GLAS). Cloud data can be seen over about 15 orbits on October 6, 2003. The data are initially laid out in the order that is was collected followed by continued movement around the scene. This version of the animation starts at the south pole and spirals slowly up to the north pole. |
| Completed |
2004-10-07 |
|
Sea Surface Height Anomalies
…
| Title |
Sea Surface Height Anomalies during El Nino/La Nina Event of 1997-1998 (WMS) |
| Abstract |
The El Nino/La Nina event in 1997-1999 was particularly intense, but was also very well observed by satellites and buoys. Changes in the normal height of the ocean's surface were observed by the TOPEX/Poseidon altimeter. |
| Completed |
2005-03-31 |
|
Sea Surface Height Anomalies
…
| Title |
Sea Surface Height Anomalies during El Nino/La Nina Event of 1997-1998 (WMS) |
| Abstract |
The El Nino/La Nina event in 1997-1999 was particularly intense, but was also very well observed by satellites and buoys. Changes in the normal height of the ocean's surface were observed by the TOPEX/Poseidon altimeter. |
| Completed |
2005-03-31 |
|
Sea Surface Height Anomaly,
…
| Title |
Sea Surface Height Anomaly, 2003-2005 (WMS) |
| Abstract |
Changes in the normal height of the ocean's surface were observed by the TOPEX/Poseidon altimeter. |
| Completed |
2005-07-13 |
|
Antarctic Plumbing: Lake Eng
…
| Title |
Antarctic Plumbing: Lake Englehardt's Subglacial Hydraulic System |
| Abstract |
ICESat satellite laser altimeter elevation profiles from 2003-2006 collected over West Antarctica reveal numerous regions of temporally varying elevation. MODIS satellite imagery over roughly the same time period collaborates where these subglacial fluctuations have occurred. These observations have led scientists to conclude that subglacial water movement is happening in this lake region, revealing a widespread, dynamic subglacial water system that could provide important insights into ice flow and the mass balance of Antarctica's ice. |
| Completed |
2007-02-13 |
|
Antarctic Plumbing: Lake Eng
…
| Title |
Antarctic Plumbing: Lake Englehardt's Subglacial Hydraulic System |
| Abstract |
ICESat satellite laser altimeter elevation profiles from 2003-2006 collected over West Antarctica reveal numerous regions of temporally varying elevation. MODIS satellite imagery over roughly the same time period collaborates where these subglacial fluctuations have occurred. These observations have led scientists to conclude that subglacial water movement is happening in this lake region, revealing a widespread, dynamic subglacial water system that could provide important insights into ice flow and the mass balance of Antarctica's ice. |
| Completed |
2007-02-13 |
|
Antarctic Plumbing: Lake Eng
…
| Title |
Antarctic Plumbing: Lake Englehardt's Subglacial Hydraulic System |
| Abstract |
ICESat satellite laser altimeter elevation profiles from 2003-2006 collected over West Antarctica reveal numerous regions of temporally varying elevation. MODIS satellite imagery over roughly the same time period collaborates where these subglacial fluctuations have occurred. These observations have led scientists to conclude that subglacial water movement is happening in this lake region, revealing a widespread, dynamic subglacial water system that could provide important insights into ice flow and the mass balance of Antarctica's ice. |
| Completed |
2007-02-13 |
|
Microwave Radiometer/Scatter
…
| Name of Image |
Microwave Radiometer/Scatterometer and Altimeter - Skylab Experiment S193 |
| Date of Image |
1970-01-01 |
| Full Description |
This 1970 photograph shows Skylab's Microwave Radiometer/Scatterometer and Altimeter, one of the major components for an Earth Resources Experiment Package (EREP). It was designed to study varying ocean surface, soil erosion, sea and lake ice, snow cover, seasonal vegetational changes, flooding, rainfall and soil types. The overall purpose of the EREP was to test the use of sensors that operated in the visible, infrared, and microwave portions of the electromagnetic spectrum to monitor and study Earth resources. The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments. |
|
Valles Marineris: The Grand
…
| Title |
Valles Marineris: The Grand Canyon of Mars |
| Explanation |
The largest canyon in the Solar System [ http://www.nineplanets.org/overview.html ] cuts a wide swath across the face of Mars [ http://www.nineplanets.org/mars.html ]. Named Valles Marineris [ http://astrogeology.usgs.gov/Projects/VallesMarineris/ ], the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. By comparison, the Earth's Grand Canyon [ http://en.wikipedia.org/wiki/Grand_Canyon ] in Arizona, USA is 800 kilometers long, 30 kilometers across, and 1.8 kilometers deep. The origin of the Valles Marineris [ http://en.wikipedia.org/wiki/Valles_Marineris ] remains unknown, although a leading hypothesis holds that it started as a crack [ http://antwrp.gsfc.nasa.gov/apod/ap980310.html ] billions of years ago as the planet cooled [ http://helio.estec.esa.nl/intermarsnet/redreport/node20.html ]. Recently [ http://antwrp.gsfc.nasa.gov/apod/ap020531.html ], several geologic processes have been identified in the canyon [ http://www.windows.ucar.edu/cgi-bin/tour.cgi?link=/mars/interior/Valles_Marineris.html&sw=false&sn=4444&d=/mars/interior&edu=mid&br=graphic&back=/mars/exploring/MGS_altimeter_OMons.html&cd=false&tour=&fr=f ]. The above mosaic [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-mars.html ] was created [ http://nssdc.gsfc.nasa.gov/photo_gallery/caption/marsglobe1.txt ] from over 100 images of Mars [ http://antwrp.gsfc.nasa.gov/apod/mars.html ] taken by Viking [ http://pds.jpl.nasa.gov/planets/welcome/viking.htm ] Orbiters in the 1970s. |
|
The Topography of Mars
| Title |
The Topography of Mars |
| Explanation |
Mars has its ups and downs. Visible on the above interactive topographic map [ http://ltpwww.gsfc.nasa.gov/tharsis/Mars_topography_from_MOLA/ ] of the surface of Mars [ http://www.nineplanets.org/mars.html ] are giant volcanoes [ http://antwrp.gsfc.nasa.gov/apod/ap000529.html ], deep valleys [ http://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search?Mars+valley ], impact craters [ http://antwrp.gsfc.nasa.gov/apod/ap010108.html ], and terrain considered unusual [ http://antwrp.gsfc.nasa.gov/apod/ap010327.html ] and even mysterious [ http://antwrp.gsfc.nasa.gov/apod/ap980407.html ]. Particularly notable are the volcanoes of the Tharsis province [ http://antwrp.gsfc.nasa.gov/apod/ap990618.html ], visible on the left in (false-color) red and white, which are taller than any mountains on Earth [ http://www.highalpex.com/Peaklist/top100.html ]. Just to the left of center is Valles Marineris [ http://antwrp.gsfc.nasa.gov/apod/ap950720.html ], a canyon much longer and deeper than Earth's Grand Canyon [ http://www.nps.gov/grca/ ]. On the right in blue is the Hellas Planitia [ http://www.solarviews.com/cap/mgs/mgstopo5.htm ], a basin over 2000 kilometers wide that was likely created by a collision with an asteroid [ http://antwrp.gsfc.nasa.gov/apod/asteroids.html ]. Mars has many smooth lowlands in the north [ http://antwrp.gsfc.nasa.gov/apod/ap980924.html ], and many rough highlands in the south [ http://antwrp.gsfc.nasa.gov/apod/ap991203.html ]. This map was created by the Mars Orbital Laser Altimeter [ http://ltpwww.gsfc.nasa.gov/tharsis/mola.html ] (MOLA) on board the robot Mars Global Surveyor [ http://mars.jpl.nasa.gov/mgs/ ] currently orbiting Mars [ http://www.sciam.com/1196issue/1196kargel.html ]. MOLA measures heights on Mars [ http://antwrp.gsfc.nasa.gov/apod/mars.html ] by precisely determining the time it takes for a low power laser beam [ http://www.howstuffworks.com/laser.htm ] to bounce off [ http://ltpwww.gsfc.nasa.gov/tharsis/measure.html ] the surface. Zoom in by clicking anywhere on the above map [ http://ltpwww.gsfc.nasa.gov/tharsis/map_lab.html ]. |
|
All of Mars
| Title |
All of Mars |
| Explanation |
From pole [ http://antwrp.gsfc.nasa.gov/apod/ap981216.html ] to pole [ http://antwrp.gsfc.nasa.gov/apod/ap991203.html ], from east to west, this is all of Mars [ http://www.nineplanets.org/mars.html ]. The above picture [ http://ltpwww.gsfc.nasa.gov/tharsis/ngs.html ] was digitally reconstructed from over 200 million laser altimeter measurements [ http://ltpwww.gsfc.nasa.gov/tharsis/measure.html ] taken by the Mars Global Surveyor spacecraft [ http://mars.jpl.nasa.gov/mgs/overvu/overview.html ] currently orbiting Mars [ http://antwrp.gsfc.nasa.gov/apod/mars.html ]. The image strips Mars [ http://www.solarviews.com/eng/mars.htm ] of its clouds [ http://antwrp.gsfc.nasa.gov/apod/ap010417.html ] and dust [ http://antwrp.gsfc.nasa.gov/apod/ap001009.html ], and renders the whole surface visible simultaneously in its true daytime color. Particularly notable are the volcanoes [ http://www.geo.mtu.edu/volcanoes/world.html ] of the Tharsis province [ http://volcano.und.nodak.edu/vwdocs/planet_volcano/mars/Shields/tharsis. html ], visible on the left, which are taller than any mountains on Earth. Just to the left of center is Valles Marineris [ http://www.solarviews.com/cap/mars/me07s078.htm ], a canyon much longer and deeper Earth's Grand Canyon [ http://www.kaibab.org/geology/gc_geol.htm ]. On the right, south of the center, is the Hellas Planitia [ http://cmex- www.arc.nasa.gov/CMEXCD/NSTA95/TeachCen/TOPO/Act3/Act3.htm ], a basin over 2000 kilometers wide that was likely created by a collision with an asteroid [ http://space.about.com/science/space/library/weekly/aa022597.htm ]. Mars has many smooth lowlands in the north, and many rough highlands in the south. Mars has just passed its closest approach [ http://antwrp.gsfc.nasa.gov/apod/ap010615.html ] to Earth since 1988 and can be seen shining brightly in the evening sky. |
|
Carving Ma'adim Vallis
| Title |
Carving Ma'adim Vallis |
| Explanation |
Just as erosion from the Colorado River carved the Grand Canyon [ http://www.aqd.nps.gov/grd/parks/grca/ ] on Earth, a river of flood water may have carved Ma'adim Vallis, one of the largest canyons on Mars [ http://antwrp.gsfc.nasa.gov/apod/ap970627.html ]. Researchers have presented strong evidence [ http://www.nasm.edu/nasm/pa/nasmnews/pr/research/ 062002.htm ] for such a scenario [ http://www.sciencemag.org/cgi/content/short/296/5576/2209 ] based on elevation data recorded by the MOLA [ http://ltpwww.gsfc.nasa.gov/tharsis/mola.html ] (Mars Orbiter Laser Altimeter) experiment on the Mars Global Surveyor [ http://mars.jpl.nasa.gov/mgs/ ] spacecraft. This false-color, detailed, topographical [ http://antwrp.gsfc.nasa.gov/apod/ap010628.html ] map of MOLA data shows in blue the area of an enormous complex of lakes that are thought [ http://www.nasm.si.edu/ceps/research/mars/irwin_lakes.htm ] to have existed over three and a half billion years ago in the southern highlands of Mars. As the largest lake spilled over the low point in its boundary a torrential flood would have moved north, along the direction indicated by the arrow, carving the sinuous Ma'adim Vallis. At the north end of Ma'adim Vallis, the flood waters would have poured into large, round Gusev Crater [ http://www.psrd.hawaii.edu/Sept98/GusevMars.html ]. Since standing bodies of surface water are thought to be favorable for ancient martian microbial life [ http://science.nasa.gov/newhome/headlines/ ast11jun99_1.htm ], Gusev Crater has been suggested as a landing site for future Mars missions [ http://mars.jpl.nasa.gov/missions/future/ express.html ]. |
|
Valles Marineris: The Grand
…
| Title |
Valles Marineris: The Grand Canyon of Mars |
| Explanation |
The largest canyon in the Solar System [ http://www.nineplanets.org/overview.html ] cuts a wide swath across the face of Mars [ http://www.nineplanets.org/mars.html ]. Named Valles Marineris [ http://astrogeology.usgs.gov/Projects/VallesMarineris/ ], the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. By comparison, the Earth's Grand Canyon [ http://www.aqd.nps.gov/grd/parks/grca/ ] in Arizona, USA is 800 kilometers long, 30 kilometers across, and 1.8 kilometers deep. The origin of the Valles Marineris [ http://mars.jpl.nasa.gov/mep/science/vm.html ] remains unknown, although a leading hypothesis holds that it started as a crack [ http://antwrp.gsfc.nasa.gov/apod/ap980310.html ] billions of years ago as the planet cooled [ http://helio.estec.esa.nl/intermarsnet/redreport/node20.html ]. Recently [ http://antwrp.gsfc.nasa.gov/apod/ap020531.html ], several geologic processes have been identified in the canyon [ http://www.windows.ucar.edu/cgi-bin/tour.cgi?link=/mars/interior/Valles_Marineris.html&sw=false&sn=4444&d=/mars/interior&edu=mid&br=graphic&back=/mars/exploring/MGS_altimeter_OMons.html&cd=false&tour=&fr=f ]. The above mosaic [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-mars.html ] was created [ http://nssdc.gsfc.nasa.gov/photo_gallery/caption/marsglobe1.txt ] from over 100 images of Mars [ http://antwrp.gsfc.nasa.gov/apod/mars.html ] taken by Viking [ http://pds.jpl.nasa.gov/planets/welcome/viking.htm ] Orbiters in the 1970s. |
|
Frosty Mountains on Mars
| Title |
Frosty Mountains on Mars |
| Explanation |
What causes the unusual white color on some Martian mountains? The answer can be guessed by noticing that the bright areas disappear as springtime [ http://antwrp.gsfc.nasa.gov/apod/ap030422.html ] takes hold in the south of Mars: dry ice. Dry carbon dioxide ice [ http://www.howstuffworks.com/question264.htm ] sublimates directly to gas from its frozen state. The frosty mountains, named Charitum Montes [ http://www.msss.com/mars_images/moc/2003/06/10/ ], have been covered with carbon dioxide [ http://scifun.chem.wisc.edu/chemweek/CO2/CO2.html ] ice over the Martian winter. The serene scene pictured above [ http://www.msss.com/mars_images/moc/2003/07/02/index.html ] is not a photograph, but rather a computationally constructed digital illusion resulting from the fusion of two color images from the Mars Orbital Camera and topographic data from the Mars Orbiter Laser Altimeter [ http://mars.jpl.nasa.gov/mgs/sci/mola/mola.html ]. Both instruments operate from the Mars Global Surveyor [ http://mars.jpl.nasa.gov/mgs/ ] robot spacecraft currently orbiting Mars [ http://www.nineplanets.org/mars.html ]. The red planet continues to grow larger [ http://antwrp.gsfc.nasa.gov/apod/ap030724.html ] in terrestrial skies as Earth and Mars move closer to their recent-record closest approach [ http://science.nasa.gov/headlines/y2003/18jun_approachingmars.htm ] on August 27. |
|
3-D Mars' North Pole
| Title |
3-D Mars' North Pole |
| Explanation |
This dramatic premier [ http://ltpwww.gsfc.nasa.gov/tharsis/agu_f98.html ] three-dimensional visualization of Mars' north pole is based on elevation measurements made by an orbiting laser. During the Spring and Summer [ http://ltpwww.gsfc.nasa.gov/tharsis/npole.html ] of 1998 the Mars Orbiter Laser Altimeter [ http://ltpwww.gsfc.nasa.gov/tharsis/mola.html#Introduction ] (MOLA) flashed laser pulses toward the Martian surface from the Global Surveyor spacecraft and recorded the time it took to detect the reflection [ http://ltpwww.gsfc.nasa.gov/tharsis/mola.html#Principles ]. This timing data has now been translated to a detailed topographic map of Mars' north polar terrain [ http://antwrp.gsfc.nasa.gov/apod/ap980924.html ]. The map indicates that the ice cap is is about 1,200 kilometers across, a maximum of 3 kilometers thick, and cut by canyons and troughs up to 1 kilometer deep. The measurements also [ http://earth.agu.org/pubs/toc/gl/gl_25_24.html ] indicate that the cap is composed primarily of water ice with a total volume of only about four percent of planet Earth's Antarctic ice sheet [ http://antwrp.gsfc.nasa.gov/apod/ap951222.html ]. In all it represents at most a tenth of the amount of water some scientists believe once existed on ancient Mars [ http://www.sciam.com/1196issue/1196kargel.html ]. Where did all the water [ http://humbabe.arc.nasa.gov/mgcm/faq/wetmars.html ] go? |
|
| Description |
*Why is Olympus Mons so big?* The main difference between the volcanoes on Mars and Earth is their size, volcanoes in the Tharsis region of Mars are 10 to 100 times larger than those anywhere on Earth. The lava flows on the Martian surface are observed to be much longer, probably a result of higher eruption rates and lower surface gravity. Another reason why the volcanoes on Mars are so massive is because the crust on Mars doesn't move the way it does on Earth. On Earth, the hot spots remain stationary but crustal plates are moving above them. The Hawaiian islands result from the northwesterly movement of the Pacific plate over a stationary hotspot producing lava. As the plate moves over the hotspot, new volcanoes are formed and the existing ones become extinct. This distributes the total volume of lava among many volcanoes rather than one large volcano. On Mars, the crust remains stationary and the lava piles up in one, very large volcano.*For more on Olympus Mons: 3-D image of Olympus Mons (you'll need 3-D glasses!)Earth and Space Network [ http://www.earthspace.net/solar_system/mars_html/mars_surface.html ]University of Michigan [ http://www.windows.umich.edu/cgi-bin/tour.cgi?link=/mars/interior/Martian_volcanoes.html&sw=false&sn=4444&d=/mars/interior&edu=mid&br=graphic&back=/mars/exploring/MGS_altimeter_OMons.html&cd=false&tour=&fr=f ]* |
|
| Description |
*Full Res(683 kB)**Winding Side Canyon (Louros Valles)* Viewers experience roller-coaster twists and turns as they fly up a winding tributary valley that feeds into Valles Marineris, the "Grand Canyon of Mars." Geologists think channels such as these were carved by water as it escaped through faults and cracks in the subsurface. This caused the ground above it to collapse, leaving a meandering channel that resembles a stream valley on Earth. This scene comes from "Flight Through Mariner Valley," an exciting video produced for NASA by the Jet Propulsion Laboratory. The video takes viewers on a simulated flight into Valles Marineris, where they explore its scenic wonders as their imaginary scout ship dives low over landslides and races through winding canyons. The video features high-resolution images from Arizona State University's Thermal Emission Imaging System multi-band camera on NASA's Mars Odyssey. The images, which show details as small as 300 meters (1,000 feet) across, were taken at infrared wavelengths during the Martian daytime. Scientists joined hundreds of individual frames from the camera into a giant mosaic, then colored the mosaic to approximate how Mars would appear to the human eye. To give the mosaic depth and height, moviemakers fitted it to a computerized topographic model for Valles Marineris. This was developed using hundreds of thousands of altitude measurements by the Mars Orbiter Laser Altimeter, an instrument on NASA's Mars Global Surveyor spacecraft. Credit: NASA/JPL/Arizona State University |
|
| Description |
*Full Res (1.3 MB)**Mars Canyon with Los Angeles for Scale* A "Grand Canyon of Mars" slices across the Red Planet near its equator. This canyon -- Valles Marineris, or the Mariner Valley -- is 10 times longer and deeper than Arizona's Grand Canyon, and 20 times wider. As the picture shows, you could drop the whole Los Angeles basin into a small part of Valles Marineris and leave plenty of room to spare. In length, the canyon extends far enough that it could reach across the United States from East Coast to West Coast, while its rim stands more than 25,000 feet high, nearly as tall as Earth's Mount Everest. This scene comes from "Flight Through Mariner Valley," an exciting video produced for NASA by the Jet Propulsion Laboratory. The video takes viewers on a simulated flight into Valles Marineris, where they explore its scenic wonders as their imaginary scout ship dives low over landslides and races through winding canyons. The video features high-resolution images from Arizona State University's Thermal Emission Imaging System multi-band camera on NASA's Mars Odyssey. The images, which show details as small as 300 meters (1,000 feet) across, were taken at infrared wavelengths during the Martian daytime. Scientists joined hundreds of individual frames from the camera into a giant mosaic, then colored the mosaic to approximate how Mars would appear to the human eye. To give the mosaic depth and height, moviemakers fitted it to a computerized topographic model for Valles Marineris. This was developed using hundreds of thousands of altitude measurements by the Mars Orbiter Laser Altimeter, an instrument on NASA's Mars Global Surveyor spacecraft. Credit: NASA/JPL/Arizona State University |
|
| Description |
*Full Res(1.2 MB)**Mars Canyon View* Flying through the canyons and over the ridges of Valles Marineris, viewers can experience some of the thrills that gripped explorers who pushed into unknown regions on Earth. Buried in the rocks of this magnificent Martian canyon lies a history book of Mars that scientists have just begun to open. This scene comes from "Flight Through Mariner Valley," an exciting video produced for NASA by the Jet Propulsion Laboratory. The video takes viewers on a simulated flight into Valles Marineris, where they explore its scenic wonders as their imaginary scout ship dives low over landslides and races through winding canyons. The video features high-resolution images from Arizona State University's Thermal Emission Imaging System multi-band camera on NASA's Mars Odyssey. The images, which show details as small as 300 meters (1,000 feet) across, were taken at infrared wavelengths during the Martian daytime. Scientists joined hundreds of individual frames from the camera into a giant mosaic, then colored the mosaic to approximate how Mars would appear to the human eye. To give the mosaic depth and height, moviemakers fitted it to a computerized topographic model for Valles Marineris. This was developed using hundreds of thousands of altitude measurements by the Mars Orbiter Laser Altimeter, an instrument on NASA's Mars Global Surveyor spacecraft. Credit: NASA/JPL/Arizona State University |
|
Carbon-Dioxide Frost Settlin
…
| title |
Carbon-Dioxide Frost Settling from Seasonal Outbursts on Mars (Movie) |
| Description |
Carbon-Dioxide Frost Settling from Seasonal Outbursts on Mars (Movie) This movie, constructed by overlaying a time series of images taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), shows seasonal changes and unearthly processes that occur in Mars' south polar seasonal frost cap. More >> [ http://mars.jpl.nasa.gov/mro/gallery/video/index.html#CarbonDioxideFrost ] |
|
Nalubaale Dam, Uganda: Image
…
nasa, nasaimageofthedaygalle
…
Dam KML file for use with ea
…
nalubaale_etm_2001331
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2001-11-27 |
| creator |
NASA -- NASA image by Robert Simmon, based on landsat.gsfc.nasa.gov/ Landsat-7 data provided by the UMD glcf.umiacs.umd.edu/index.shtml Global Land Cover Facility. |
| identifier |
nalubaale_etm_2001331 |
|
A Quiet Equatorial Pacific:
…
nasa, nasaimageofthedaygalle
…
Some climate forecast models
…
ssh_jas_2003307
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-11-03 |
| creator |
NASA -- Image courtesy NASA/JPL sealevel.jpl.nasa.gov/ Ocean Surface Topography Team |
| identifier |
ssh_jas_2003307 |
|
Pacific Climate Calm: Image
…
nasa, nasaimageofthedaygalle
…
In early 2006, a weak eartho
…
ssh_jas_2006144
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2006-05-21 |
| creator |
NASA -- Image courtesy NASA/JPL Ocean Surface Topography from Space team |
| identifier |
ssh_jas_2006144 |
|
3-D Data from ICESat: Image
…
nasa, nasaimageofthedaygalle
…
Orbiting the Earth at nearly
…
ICESat_cloud
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-01-12 |
| creator |
NASA -- Image courtesy NASA |
| identifier |
ICESat_cloud |
|
Venus Rising
nasa, nasaimageofthedaygalle
…
This hemispheric view of Ven
…
508439main_PIA00007
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2011-01-05 |
| creator |
NASA |
| identifier |
508439main_PIA00007 |
|
Antarctica's Land and Ice El
…
nasa, nasaimageofthedaygalle
…
Launched January 12, 2003, N
…
ICESat_AntElevation
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-01-12 |
| creator |
NASA -- NASA image (top) courtesy Christopher Shuman, ICESat Deputy Project Scientist, Goddard Space Flight Center. Artists' rendering (below) courtesy Greg Shirah and Alex Kekesi, svs.gsfc.nasa.gov Scientific Visualizations Studio, Goddard Space Flight Center. |
| identifier |
ICESat_AntElevation |
|
Vertical Profile of the Smok
…
nasa, nasaimageofthedaygalle
…
A new instrument in orbit ab
…
GLAS_2003301
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-10-28 |
| creator |
NASA -- Image courtesy Steve Palm, https://icesat.gsfc.nasa.gov/ ICESat Team, NASA Goddard Space Flight Center |
| identifier |
GLAS_2003301 |
|
Hemispheric View of Venus Ce
…
PIA00157
Sol (our sun)
Imaging Radar
| Title |
Hemispheric View of Venus Centered at 0 Degrees East Longitude |
| Original Caption Released with Image |
The hemispheric view of Venus, as revealed by more than a decade of radar investigations culminating in the 1990-1994 Magellan mission, is centered at 0 degrees east longitude. The Magellan spacecraft imaged more than 98% of Venus at a resolution of about 100 meters, the effective resolution of this image is about 3 km. A mosaic of the Magellan images (most with illumination from the west) forms the image base. Gaps in the Magellan coverage were filled with images from the Earth-based Arecibo radar in a region centered roughly on 0 degree latitude and longitude, and with a neutral tone elsewhere (primarily near the south pole). The composite image was processed to improve contrast and to emphasize small features, and was color-coded to represent elevation. Gaps in the elevation data from the Magellan radar altimeter were filled with altimetry from the Venera spacecraft and the U.S. Pioneer Venus missions. An orthographic projection was used, simulating a distant view of one hemisphere of the planet. The Magellan mission was managed for NASA by Jet Propulsion Laboratory (JPL), Pasadena, CA. Data processed by JPL, the Massachusetts Institute of Technology, Cambridge, MA, and the U.S. Geological Survey, Flagstaff, AZ. |
|
Hemispheric View of Venus Ce
…
PIA00159
Sol (our sun)
Imaging Radar
| Title |
Hemispheric View of Venus Centered at 180 Degrees East Longitude |
| Original Caption Released with Image |
The hemispheric view of Venus, as revealed by more than a decade of radar investigations culminating in the 1990-1994 Magellan mission, is centered at 180 degrees east longitude. The Magellan spacecraft imaged more than 98% of Venus at a resolution of about 100 meters, the effective resolution of this image is about 3 km. A mosaic of the Magellan images (most with illumination from the west) forms the image base. Gaps in the Magellan coverage were filled with images from the Earth-based Arecibo radar in a region centered roughly on 0 degree latitude and longitude, and with a neutral tone elsewhere (primarily near the south pole). The composite image was processed to improve contrast and to emphasize small features, and was color-coded to represent elevation. Gaps in the elevation data from the Magellan radar altimeter were filled with altimetry from the Venera spacecraft and the U.S. Pioneer Venus missions. An orthographic projection was used, simulating a distant view of one hemisphere of the planet. The Magellan mission was managed for NASA by Jet Propulsion Laboratory (JPL), Pasadena, CA. Data processed by JPL, the Massachusetts Institute of Technology, Cambridge, MA, and the U.S. Geological Survey, Flagstaff, AZ. |
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Hemispheric View of Venus Ce
…
PIA00158
Sol (our sun)
Imaging Radar
| Title |
Hemispheric View of Venus Centered at 90 Degrees East Longitude |
| Original Caption Released with Image |
The hemispheric view of Venus, as revealed by more than a decade of radar investigations culminating in the 1990-1994 Magellan mission, is centered at 90 degrees east longitude. The Magellan spacecraft imaged more than 98% of Venus at a resolution of about 100 meters, the effective resolution of this image is about 3 km. A mosaic of the Magellan images (most with illumination from the west) forms the image base. Gaps in the Magellan coverage were filled with images from the Earth-based Arecibo radar in a region centered roughly on 0 degree latitude and longitude, and with a neutral tone elsewhere (primarily near the south pole). The composite image was processed to improve contrast and to emphasize small features, and was color-coded to represent elevation. Gaps in the elevation data from the Magellan radar altimeter were filled with altimetry from the Venera spacecraft and the U.S. Pioneer Venus missions. An orthographic projection was used, simulating a distant view of one hemisphere of the planet. The Magellan mission was managed for NASA by Jet Propulsion Laboratory (JPL), Pasadena, CA. Data processed by JPL, the Massachusetts Institute of Technology, Cambridge, MA, and the U.S. Geological Survey, Flagstaff, AZ. |
|
Hemispheric View of Venus Ce
…
PIA00160
Sol (our sun)
Imaging Radar
| Title |
Hemispheric View of Venus Centered at 270 Degrees East Longitude |
| Original Caption Released with Image |
The hemispheric view of Venus, as revealed by more than a decade of radar investigations culminating in the 1990-1994 Magellan mission, is centered at 270 degrees east longitude. The Magellan spacecraft imaged more than 98% of Venus at a resolution of about 100 meters, the effective resolution of this image is about 3 km. A mosaic of the Magellan images (most with illumination from the west) forms the image base. Gaps in the Magellan coverage were filled with images from the Earth-based Arecibo radar in a region centered roughly on 0 degree latitude and longitude, and with a neutral tone elsewhere (primarily near the south pole). The composite image was processed to improve contrast and to emphasize small features, and was color-coded to represent elevation. Gaps in the elevation data from the Magellan radar altimeter were filled with altimetry from the Venera spacecraft and the U.S. Pioneer Venus missions. An orthographic projection was used, simulating a distant view of one hemisphere of the planet. The Magellan mission was managed for NASA by Jet Propulsion Laboratory (JPL), Pasadena, CA. Data processed by JPL, the Massachusetts Institute of Technology, Cambridge, MA, and the U.S. Geological Survey, Flagstaff, AZ. |
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TOPEX/El Niño Watch - June 2
…
PIA00735
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - June 25, 1997 |
| Original Caption Released with Image |
This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S./French TOPEX/POSEIDON satellite. The image shows sea surface height relative to normal ocean conditions on June 25, 1997 and provides more convincing information that the weather-disrupting phenomenon known as El Niño is back and getting stronger. The white and red areas indicate unusual patterns of heat storage, in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it s about 10 centimeters (4 inches) above normal. The surface area covered by the warm water mass is about one and one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21-30 degrees Celsius (70-85 degrees Fahrenheit), is about 30 times the volume of water in all the U.S. Great Lakes combined. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmosphere system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and Atmospheric Administration, (NOAA), has issued an advisory indicating the presence of the early indications of El Niño conditions. |
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TOPEX/El Niño Watch - Indone
…
PIA00742
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - Indonesia Area, December, 1996 and August, 1997 |
| Original Caption Released with Image |
These images of the Pacific Ocean near Indonesia were produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The images show sea surface height relative to normal ocean conditions during December 1996 and August 1997. The difference in sea level between these months is tied to the movement of warm water away from Indonesia. In December (left image), red and white areas indicate the presence of warm, higher than average sea level around Indonesia. At this time, massive amounts of warm water were detected around Indonesia by the TOPEX/Poseidon satellite. The warm, wet air from this water fed the normally heavy rainfall in this region. By August 1997 (right image), sea level had dropped well below average as shown by purple areas (sea level at least 18 centimeters (7 inches) below normal). The warm water had shifted east towards the west coast of North and South America, taking the rains with it. The white and red areas indicate patterns of unusually high heat storage, in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The movement of warm water away from the western Pacific is tied to the weather-disrupting phenomenon known as El Niño. The departure of the large mass of warm water that is normally located near Indonesia has affected where rain clouds form, altered the typical atmospheric patterns and brought devastating drought to Indonesia. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. Using these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmosphere system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and Atmospheric Administration (NOAA) has issued an advisory indicating the presence of the early indications of El Niño conditions. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov/ |
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TOPEX/El Niño Watch - March
…
PIA00734
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - March thru June, 1997 |
| Original Caption Released with Image |
These four views of the Pacific Ocean were produced using sea surface height measurements taken by the U.S./French TOPEX/POSEIDON satellite. The images show sea surface height relative to normal ocean conditions from March 1997 through June 1997. This evolutionary view is providing oceanographers with more convincing information that the weather-disrupting phenomenon known as El Niño is back and getting stronger. The white and red areas indicate unusual patterns of heat storage, in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it s about 10 centimeters (4 inches) above normal. The surface area covered by the warm water mass is about one and one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21-30 degrees Celsius (70-85 degrees Fahrenheit), is about 30 times the volume of water in all the U.S. Great Lakes combined. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmosphere system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and Atmospheric Administration, (NOAA), has issued an advisory indicating the presence of the early indications of El Niño conditions. |
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TOPEX/El Niño Watch - Octobe
…
PIA00741
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - October 3, 1997 |
| Original Caption Released with Image |
This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S./French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Oct. 3, 1997 as the warm water associated with El Niño (in white) spreads northward along the entire coast of North America from the equator all the way to Alaska. The warm water pool in tropical Pacific resulting from El Niño seems to have stabilized. The white and red areas indicate unusual patterns of heat storage, in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The surface area covered by the warm water mass is about one and one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21 and 30 C (70 to 85 F), carries the amount of heat equal to 100 times the amount of fossil fuel energy consumed by the entire U.S. population during one year. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmosphere system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and Atmospheric Administration (NOAA) has issued an advisory indicating the presence of a strong El Niño condition throughout the coming winter. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov/ |
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TOPEX/El Niño Watch- Septemb
…
PIA00736
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch- September 20, 1997 |
| Original Caption Released with Image |
This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S./French TOPEX/POSEIDON satellite. The image shows sea surface height relative to normal ocean conditions on September 20, 1997 and provides more convincing information that the weather-disrupting phenomenon known as El Niño is back and getting stronger. The white and red areas indicate unusual patterns of heat storage, in the white areas, the sea surface is between 14 and 32 centimeters ( 6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The surface area covered by the warm water mass is about one and one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21-30 degrees Celsius (70-85 degrees Fahrenheit), is about 30 times the volume of water in all the U.S. Great Lakes combined. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmosphere system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and Atmospheric Administration, (NOAA), has issued an advisory indicating the presence of the early indications of El Niño conditions. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov/ |
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TOPEX/El Niño Watch - El Niñ
…
PIA01140
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - El Niño Rhythm, Dec, 10, 1997 |
| Original Caption Released with Image |
This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Dec.10, 1997 and sea surface height is an indicator of the heat content of the ocean. The volume and area of the warm water pool related to El Niño has increased again after reaching a temporary low around Dec. 1. TOPEX/Poseidon has been tracking the fluctuations of the El Niño warm pool since it began early this year. Oceanographers believe the recent increases and decreases in the size of the warm water pool at the equator are part of the natural rhythm of El Niño and that the warm pool is occasionally pumped up by wind bursts blowing from the western and central Pacific Ocean. Each wind burst has triggered a temporary increase in area and volume of the warm pool. These data collected throughout 1997 have provided scientists with their first detailed view of how El Niño's warm pool behaves because the TOPEX/Poseidon satellite measures the changing sea surface height with unprecedented precision. In this image, the white and red areas indicate unusual patterns of heat storage, in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmosphere system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and Atmospheric Administration, (NOAA), has issued an advisory indicating the presence of a strong El Niño condition throughout the winter. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov |
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TOPEX/El Niño Watch - El Niñ
…
PIA01164
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - El Niño Warm Water Pool Decreasing, Jan, 08, 1998 |
| Original Caption Released with Image |
This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Jan. 8, 1998, and sea surface height is an indicator of the heat content of the ocean. The volume of the warm water pool related to the El Niño has decreased by about 40 percent since its maximum in early November, but the area of the warm water pool is still about one and a half times the size of the continental United States. The volume measurements are computed as the sum of all the sea surface height changes as compared to normal ocean conditions. In addition, the maximum water temperature in the eastern tropical Pacific, as measured by the National Oceanic and Atmospheric Administration (NOAA), is still higher than normal. Until these high temperatures diminish, the El Niño warm water pool still has great potential to disrupt global weather because the high water temperatures directly influence the atmosphere. Oceanographers believe the recent decrease in the size of the warm water pool is a normal part of El Niño's natural rhythm. TOPEX/Poseidon has been tracking these fluctuations of the El Niño warm pool since it began in early 1997. These sea surface height measurements have provided scientists with their first detailed view of how El Niño's warm pool behaves because the TOPEX/Poseidon satellite measures the changing sea surface height with unprecedented precision. In this image, the white and red areas indicate unusual patterns of heat storage, in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmosphere system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and Atmospheric Administration, (NOAA), has issued an advisory indicating the presence of a strong El Niño condition throughout the winter. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov |
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The Geodesy Campaign
PIA02023
Sol (our sun)
Mars Orbiter Camera
| Title |
The Geodesy Campaign |
| Original Caption Released with Image |
Every day, Mars Global Surveyor (MGS) circles the red planet just over twelve times, and from their vantage point at 400 km altitude, the fisheye lenses of the Mars Orbiter Camera (MOC)Wide Angle (WA) cameras can see the entire surface. During typical operations, highly-summed two-color image strips are transmitted for each orbit and assembled into daily global weather maps, with a resolution of about 7.5 km (4.6 miles) per pixel. The small size and low resolution of these strips leaves most of the data bandwidth available for higher-priority Narrow Angle images. During May 1999, however, the Wide Angle cameras are being used instead to map the whole planet at the intrinsic resolution of the WA camera -- 230 meters (750 feet) per pixel. While the blue WA camera continues to capture the global map so that daily weather can still be monitored, the other WA camera (with the red filter) is building up swaths of full-resolution coverage. The Deep Space Network is tracking the spacecraft 24 hours a day during this geodesy campaign, and imaging data are being returned for about two-thirds of the time at 69 kbits/sec(somewhat faster than a 56K modem). During the other third of the time, the spacecraft is transmitting back to Earth one day's worth of recorded data from the other science instruments. Geodesy is the measurement of a planet's shape and the location of features on its surface. The intent of the geodesy campaign is to acquire, during a short period of time, simultaneous measurements by the Mars Orbiter Laser Altimeter (MOLA), the Radio Science (RS)investigation, and the MOC. MOLA observations provide precise, absolute measurements of a set of profiles around the planet, but their spacing is quite large relative to their resolution. RS measurements provide detailed information about the position of the spacecraft, critical to processing both the MOC and MOLA data. MOC provides both a higher resolution base map on which the other data can be overlain and, using stereoscopic measurements, provides the potential for a ten-fold improvement in the spatial resolution of the topography. Owing to the nature of the MGS orbit, the groundtrack returns to within about 30 km of a given orbit 88 orbits (about one week) later. Thus, it takes a week to build up global coverage at full resolution. Figure MOC2-127a [ http://photojournal.jpl.nasa.gov/catalog/PIA02022 ], shows the planning map of coverage during the first week of the campaign (top), and the resulting actual coverage (bottom). Gaps caused by recorder playbacks must be filled in a second week of imaging by moving the times of the playbacks. Also in the second week, stereo coverage is acquired by re-imaging areas from adjacent orbits at aside-looking angle. Figure MOC2-127b shows an example of such stereo from the Mare Tyrrhenum region, centered at 27.3°S, 227.0°W (NOTE: Red-blue glasses are needed to view the stereo effect). The crater that dominates the center of Figure MOC2-127b is about 50 kilometers (31 miles) across. Stereo coverage will be completed in the third and fourth weeks. The remaining data volume will be used to fill in gaps created by data losses, and to acquire a somewhat lower resolution global color image through the blue wide angle camera. The resulting dataset will provide global color and stereo coverage at about 300 m/pixel. Although similar coverage was obtained by the Viking mission in the late 1970s, Viking took over three years to cover the planet, and there are significant variations in lighting, weather, and surface features in the Viking images. A substantial improvement in the longitude/latitude grid is expected, which will have important benefits to future Mars exploration. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. |
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The Geodesy Campaign
PIA02022
Sol (our sun)
Mars Orbiter Camera
| Title |
The Geodesy Campaign |
| Original Caption Released with Image |
Figure MOC2-127b [ http://photojournal.jpl.nasa.gov/catalog/PIA02023 ] is about 50 kilometers (31 miles) across. Stereo coverage will be completed in the third and fourth weeks. The remaining data volume will be used to fill in gaps created by data losses, and to acquire a somewhat lower resolution global color image through the blue wide angle camera. The resulting dataset will provide global color and stereo coverage at about 300 m/pixel. Although similar coverage was obtained by the Viking mission in the late 1970s, Viking took over three years to cover the planet, and there are significant variations in lighting, weather, and surface features in the Viking images. A substantial improvement in the longitude/latitude grid is expected, which will have important benefits to future Mars exploration. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO., Every day, Mars Global Surveyor (MGS) circles the red planet just over twelve times, and from their vantage point at 400 km altitude, the fisheye lenses of the Mars Orbiter Camera (MOC)Wide Angle (WA) cameras can see the entire surface. During typical operations, highly-summed two-color image strips are transmitted for each orbit and assembled into daily global weather maps, with a resolution of about 7.5 km (4.6 miles) per pixel. The small size and low resolution of these strips leaves most of the data bandwidth available for higher-priority narrow Angle images. During May 1999, however, the Wide Angle cameras are being used instead to map the whole planet at the intrinsic resolution of the WA camera -- 230 meters (750 feet) per pixel. While the blue WA camera continues to capture the global map so that daily weather can still be monitored, the other WA camera (with the red filter) is building up swaths of full-resolution coverage. The Deep Space Network is tracking the spacecraft 24 hours a day during this geodesy campaign, and imaging data are being returned for about two-thirds of the time at 69 kbits/sec (somewhat faster than a 56K modem). During the other third of the time, the spacecraft is transmitting back to Earth one day's worth of recorded data from the other science instruments. Geodesy is the measurement of a planet's shape and the location of features on its surface. The intent of the geodesy campaign is to acquire, during a short period of time, simultaneous measurements by the Mars Orbiter Laser Altimeter (MOLA), the Radio Science (RS)investigation, and the MOC. MOLA observations provide precise, absolute measurements of a set of profiles around the planet, but their spacing is quite large relative to their resolution. RS measurements provide detailed information about the position of the spacecraft, critical to processing both the MOC and MOLA data. MOC provides both a higher resolution base map on which the other data can be overlain and, using stereoscopic measurements, provides the potential for a ten-fold improvement in the spatial resolution of the topography. Owing to the nature of the MGS orbit, the groundtrack returns to within about 30 km of a given orbit 88 orbits (about one week) later. Thus, it takes a week to build up global coverage at full resolution. Figure MOC2-127a shows the planning map of coverage during the first week of the campaign (top), and the resulting actual coverage (bottom). Gaps caused by recorder playbacks must be filled in a second week of imaging by moving the times of the playbacks. Also in the second week, stereo coverage is acquired by re-imaging areas from adjacent orbits at aside-looking angle. Figure MOC2-127b [ http://photojournal.jpl.nasa.gov/catalog/PIA02023 ] shows an example of such stereo from the Mare Tyrrhenum region, centered at 27.3°S, 227.0°W (NOTE: Red-blue glasses are needed to view the stereo effect). The crater that dominates the center of |
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Warm Ocean Temperatures Blan
…
PIA00556
Sol (our sun)
Altimeter
| Title |
Warm Ocean Temperatures Blanket the Far-Western Pacific |
| Original Caption Released with Image |
These data, taken during a 10-day collection cycle ending March 9, 2001, show that above-normal sea-surface heights and warmer ocean temperatures(indicated by the red and white areas) still blanket the far-western tropical Pacific and much of the north (and south) mid-Pacific. Red areas are about 10centimeters (4 inches) above normal, white areas show the sea-surface height is between 14 and 32 centimeters (6 to 13 inches) above normal. This build-up of heat dominating the Western Pacific was first noted by TOPEX/Poseidon oceanographers more than two years ago and has outlasted the El Niño and La Niña events of the past few years. See: http://www.jpl.nasa.gov/elnino/990127.html . This warmth contrasts with the Bering Sea, Gulf of Alaska and tropical Pacific where lower-than-normal sea levels and cool ocean temperatures continue (indicated by blue areas). The blue areas are between 5 and 13centimeters (2 and 5 inches) below normal, whereas the purple areas range from 14 to 18 centimeters (6 to 7 inches) below normal. Actually, the near-equatorial ocean cooled through the fall of 2000 and into mid-winter and continues almost La Niña-like. Looking at the entire Pacific basin, the Pacific Decadal Oscillation's warm horseshoe and cool wedge pattern still dominates this sea-level height image. Most recent National Oceanic and Atmospheric Administration (NOAA) sea-surface temperature data also clearly illustrate the persistence of this basin-wide pattern. They are available at http://psbsgi1.nesdis.noaa.gov:8080/PSB/EPS/SST/climo.html The U.S.-French TOPEX/Poseidon mission is managed by JPL for NASA's Earth Science Enterprise, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. For more information on the TOPEX/Poseidon project, see: http://topex-www.jpl.nasa.gov |
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She's Back? La Niña Developi
…
PIA03665
Sol (our sun)
Altimeter
| Title |
She's Back? La Niña Developing? |
| Original Caption Released with Image |
The tropical Pacific Ocean is beginning to exhibit the characteristics of a developing La Niña condition. This image shows that the gradual cooling of the central equatorial Pacific over the past few months is continuing and the area of low sea level (shown in blue) has decreased (cooled) slightly over last few months. It is still uncertain, scientists say, that this cold pool will evolve into a long-lasting, strong La Niña situation. For a complete discussion of this evolving situation and potential implications see: http://www.noaanews.noaa.gov/stories2006/s2559.htm [ http://www.noaanews.noaa.gov/stories2006/s2559.htm ]. This image of the Pacific Ocean was produced using sea-surface height measurements taken by the U.S.-French Jason satellite. The image shows sea surface height relative to normal ocean conditions on December 31, 2005, these sea surface heights are an indicator of the changing amount of heat stored in the ocean. The purple areas in this image are about 18 centimeters (7 inches) below normal, creating a deficit in the heat supply to the surface waters. The white areas show the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions. A La Niña situation is essentially the opposite of an El Niño condition. During La Niña, the trade winds are stronger than normal and the cold water that normally exists along the coast of South America extends to the central equatorial Pacific. A La Niña reappears every three to five years and, if the present event strengthens, it will certainly reorganize global weather patterns. The U.S. portion of the Jason mission is managed by JPL for NASA's Science Mission Directorate, Washington, D.C. Research on Earth's oceans using Jason and other space-based capabilities is conducted by NASA's Science Mission Directorate to better understand and protect our home planet. |
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Pacific Ocean in Holding Pat
…
PIA03850
Sol (our sun)
Altimeter
| Title |
Pacific Ocean in Holding Pattern for El Niño |
| Original Caption Released with Image |
The Pacific Ocean doesn't show signs of anything that looks like the whopper El Niño of 1997-1998, according to the latest information from the U.S.-French ocean-observing satellite Topex/Poseidon. The data do show that the mid-equatorial Pacific Ocean has slowly warmed by about 1 degree Celsius (1.8 degrees Fahrenheit) above normal in the past few months. However, the Pacific continues to be dominated by the larger-than-El Niño /La Niña pattern called the Pacific Decadal Oscillation, which may discourage El Niño development."Except for some recent mid-Pacific warming, June 2002 looks very much like June 2001," said oceanographer Dr. William Patzert of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We're still in an E Niño holding pattern." ( See June 2001 image [ http://sealevel.jpl.nasa.gov/elnino/20010621.html ]) The Topex/Poseidon data were taken during a 10-day collection cycle ending June 14, 2002. They show that there hasn't been any fundamental change in the ocean's large-scale patterns for the past three years. The near-equatorial ocean has been very quiet, although sea levels and sea-surface temperatures are near normal or slightly warmer throughout the far western and central tropical Pacific. Red areas are about 10 centimeters (4 inches) above normal, white areas show the sea-surface height is between 14 and 32 centimeters (6 to 13inches) above normal. This warmth contrasts with the Bering Sea, Gulf of Alaska and U.S. West Coast, where lower-than-normal sea-surface levels (blue areas) and cool ocean temperatures continue. The blue areas are between 5 and 13 centimeters (2 and 5 inches)below normal, and the purple areas range from 14 to 18 centimeters (6to 7 inches) below normal. |
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Watching for the Next El Niñ
…
PIA03855
Sol (our sun)
Altimeter
| Title |
Watching for the Next El Niño |
| Original Caption Released with Image |
This Topex/Poseidon image of sea-surface heights was taken during a 10-day collection cycle ending August 7, 2002. Sea-surface heights are a measure of how much heat is stored in the ocean below to influence future planetary climate events. Since May 2001, there have been a series of warm Kelvin waves--eastward-moving ocean waves that cross the equatorial Pacific in about two months. A sizable one arrived at the South American coast last February, raising the ocean temperature by 2 degrees Celsius (3.6 degrees Fahrenheit) and triggering the National Oceanic and Atmospheric Administration's forecast for a mild El Niño in 2002. There was another wave in June, followed by the current large pool of warm water in the tropical Pacific that is now moving toward the coast of South America at a speed of 215 kilometers (134 miles) a day and will arrive there in three to four weeks, raising ocean temperatures. Scientists will continue to monitor the Pacific closely for further signs of El Niño formation and intensity. |
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NASA/French Satellite Data R
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PIA07219
Sol (our sun)
Altimeter
| Title |
NASA/French Satellite Data Reveal New Details of Tsunami |
| Original Caption Released with Image |
Displayed in blue color is the height of sea surface (shown in blue) measured by the Jason satellite two hours after the initial magnitude 9 earthquake hit the region (shown in red) southwest of Sumatra on December 26, 2004. The data were taken by a radar altimeter onboard the satellite along a track traversing the Indian Ocean when the tsunami waves had just filled the entire Bay of Bengal (see the model simulation inset image). The data shown are the changes of sea surface height from previous observations made along the same track 20-30 days before the earthquake, reflecting the signals of the tsunami waves. The maximum height of the leading wave crest was about 50 cm (or 1.6 ft), followed by a trough of sea surface depression of 40 cm. The directions of wave propagation along the satellite track are shown by the blue arrows. "Model Simulation:" Simulated changes of sea surface height caused by the earthquake two hours after the initial shock. The simulation was performed using a computer model and provided for public access via internet by Kenji Satake, National Institute of Advanced Industrial Science and Technology, Japan (http://www.ioc.unesco.org/itsu/templates/itsu/images/animation.gif). Wave crests are shown in red and troughs in blue. The track traversed by the Jason satellite was also shown. The simulated crests and troughs along the track are in agreement with the satellite observations. The map provides a basin-wide perspective for interpreting the satellite observations along a single track. |
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Distributory Fan Near Holden
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PIA04869
Sol (our sun)
Mars Orbiter Camera
| Title |
Distributory Fan Near Holden Crater |
| Original Caption Released with Image |
Click on image for larger view A region near the center of the fan has a loop, the inverted floor of a former meandering stream that was cut off as the channel adjusted its course. Meanders and cut-off meanders are the prime evidence for persistent flow of water through this area sometime early in martian history.Click on image for larger view A region near the southeast edge of the fan shows inverted channels at different levels within the sedimentary deposit, indicating a long and complex history of water-related processes. One ridge crosses over another just left of the center of this frame. The top of the lower ridge is the former floor of a channel that was transporting water and sediment toward the lower right. The top of the upper ridge was once the floor of a channel that moved material toward the right or upper right. The lower ridge is the older channel. It was completely filled and buried beneath the surface when the upper channel formed.Click on image for larger view A regional context image shows the location of the fan with a white box. West of the fan are several valleys that fed water and sediment to the crater holding the fan (labeled "Holden NE" Crater). This map is a mosaic of daytime infrared images from the Thermal Emission Imaging System on Mars Odyssey. The contours are topography relative to Mars' zero-elevation level, derived from observations by the Mars Orbiter Laser Altimeter on Mars Global Surveyor. Sunlight illuminates the scene from the upper left. The 10-kilometer scale bar is about 6.2 miles across.Click on image for larger view Additional information about Mars Global Surveyor is online at http://mars.jpl.nasa.gov/mgs/ [ http://mars.jpl.nasa.gov/mgs/ ]. The Jet Propulsion Laboratory, Pasadena, Calif., manages the Mars Global Surveyor mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. JPL's industrial partner is Lockheed Martin Space Systems, Denver, which built and operates the spacecraft., November 13, 2003 Details in a fan-shaped deposit discovered by NASA's Mars Global Surveyor orbiter provide evidence that some ancient rivers on Mars flowed for a long time, not just in brief, intense floods. The apron of debris filling the middle of this picture from the spacecraft's Mars Orbiter Camera is a hardened and eroded distributory fan, a type of geological feature that includes river deltas and alluvial fans. Sediments transported through valleys by water on early Mars formed the 13-kilometer-long (8-mile) deposit in the distant past, when it was still possible for liquid water to flow across the martian surface. Mars Orbiter Camera team members published discovery of this feature in the online edition of the journal Science. What is important about it? First, it provides unequivocal evidence that some valleys on Mars experienced persistent flow over considerable periods of time, as rivers do on Earth. Second, because the fan is today a deposit of sedimentary rock, it demonstrates that some sedimentary rocks on Mars were deposited in a liquid environment. Third, the fan's general shape, the pattern of its channels, and its low slopes provide circumstantial evidence that the feature was an actual delta -- that is, a deposit made when a river or stream enters a body of water. If so, this landform is a strong indicator that some craters and basins on Mars once held lakes. Hundreds of other locations on Mars where valleys enter craters and basins have been imaged by the Mars Orbiter Camera, but none has shown landforms like those presented here. The picture is a mosaic of images acquired between August 2000 and September 2003. The area covered 14 kilometer (8.7 miles) by 19.3 kilometers (12 miles). North is up. Sunlight illuminates the scene from the left. The spacecraft's narrow-angle camera takes grayscale images, the color added is based on information from a camera on Mars Odyssey. The fan is in an unnamed crater that is 64 kilometers (40 miles) in diameter, at 24.3 degrees south latitude, 33.5 degrees west longitude. The crater lies northeast of a larger one named Holden Crater. The fan is a fossil landform. That is, it is an eroded remnant of a somewhat larger and thicker deposit. The originally loose sediment was turned to rock and then eroded over time to present the features seen today. The channels through which sediment was transported are no longer present. Instead, only their floors remain, and these have been elevated by erosion so that former channels now stand as ridges. The floors of former channels became inverted in this way because they were more resistant to the forces of erosion, indicating they either were more strongly cemented than surrounding materials, or they have more coarse grains (which are harder to remove), or both. Closer looks at two portions of the fan show observations critical to the story. White boxes overlaid on the image show the locations of those two areas. |
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Distributory Fan Near Holden
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PIA04869
Sol (our sun)
Mars Orbiter Camera
| Title |
Distributory Fan Near Holden Crater |
| Original Caption Released with Image |
Click on image for larger view A region near the center of the fan has a loop, the inverted floor of a former meandering stream that was cut off as the channel adjusted its course. Meanders and cut-off meanders are the prime evidence for persistent flow of water through this area sometime early in martian history.Click on image for larger view A region near the southeast edge of the fan shows inverted channels at different levels within the sedimentary deposit, indicating a long and complex history of water-related processes. One ridge crosses over another just left of the center of this frame. The top of the lower ridge is the former floor of a channel that was transporting water and sediment toward the lower right. The top of the upper ridge was once the floor of a channel that moved material toward the right or upper right. The lower ridge is the older channel. It was completely filled and buried beneath the surface when the upper channel formed.Click on image for larger view A regional context image shows the location of the fan with a white box. West of the fan are several valleys that fed water and sediment to the crater holding the fan (labeled "Holden NE" Crater). This map is a mosaic of daytime infrared images from the Thermal Emission Imaging System on Mars Odyssey. The contours are topography relative to Mars' zero-elevation level, derived from observations by the Mars Orbiter Laser Altimeter on Mars Global Surveyor. Sunlight illuminates the scene from the upper left. The 10-kilometer scale bar is about 6.2 miles across.Click on image for larger view Additional information about Mars Global Surveyor is online at http://mars.jpl.nasa.gov/mgs/ [ http://mars.jpl.nasa.gov/mgs/ ]. The Jet Propulsion Laboratory, Pasadena, Calif., manages the Mars Global Surveyor mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. JPL's industrial partner is Lockheed Martin Space Systems, Denver, which built and operates the spacecraft., November 13, 2003 Details in a fan-shaped deposit discovered by NASA's Mars Global Surveyor orbiter provide evidence that some ancient rivers on Mars flowed for a long time, not just in brief, intense floods. The apron of debris filling the middle of this picture from the spacecraft's Mars Orbiter Camera is a hardened and eroded distributory fan, a type of geological feature that includes river deltas and alluvial fans. Sediments transported through valleys by water on early Mars formed the 13-kilometer-long (8-mile) deposit in the distant past, when it was still possible for liquid water to flow across the martian surface. Mars Orbiter Camera team members published discovery of this feature in the online edition of the journal Science. What is important about it? First, it provides unequivocal evidence that some valleys on Mars experienced persistent flow over considerable periods of time, as rivers do on Earth. Second, because the fan is today a deposit of sedimentary rock, it demonstrates that some sedimentary rocks on Mars were deposited in a liquid environment. Third, the fan's general shape, the pattern of its channels, and its low slopes provide circumstantial evidence that the feature was an actual delta -- that is, a deposit made when a river or stream enters a body of water. If so, this landform is a strong indicator that some craters and basins on Mars once held lakes. Hundreds of other locations on Mars where valleys enter craters and basins have been imaged by the Mars Orbiter Camera, but none has shown landforms like those presented here. The picture is a mosaic of images acquired between August 2000 and September 2003. The area covered 14 kilometer (8.7 miles) by 19.3 kilometers (12 miles). North is up. Sunlight illuminates the scene from the left. The spacecraft's narrow-angle camera takes grayscale images, the color added is based on information from a camera on Mars Odyssey. The fan is in an unnamed crater that is 64 kilometers (40 miles) in diameter, at 24.3 degrees south latitude, 33.5 degrees west longitude. The crater lies northeast of a larger one named Holden Crater. The fan is a fossil landform. That is, it is an eroded remnant of a somewhat larger and thicker deposit. The originally loose sediment was turned to rock and then eroded over time to present the features seen today. The channels through which sediment was transported are no longer present. Instead, only their floors remain, and these have been elevated by erosion so that former channels now stand as ridges. The floors of former channels became inverted in this way because they were more resistant to the forces of erosion, indicating they either were more strongly cemented than surrounding materials, or they have more coarse grains (which are harder to remove), or both. Closer looks at two portions of the fan show observations critical to the story. White boxes overlaid on the image show the locations of those two areas. |
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Distributory Fan Near Holden
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PIA04869
Sol (our sun)
Mars Orbiter Camera
| Title |
Distributory Fan Near Holden Crater |
| Original Caption Released with Image |
Click on image for larger view A region near the center of the fan has a loop, the inverted floor of a former meandering stream that was cut off as the channel adjusted its course. Meanders and cut-off meanders are the prime evidence for persistent flow of water through this area sometime early in martian history.Click on image for larger view A region near the southeast edge of the fan shows inverted channels at different levels within the sedimentary deposit, indicating a long and complex history of water-related processes. One ridge crosses over another just left of the center of this frame. The top of the lower ridge is the former floor of a channel that was transporting water and sediment toward the lower right. The top of the upper ridge was once the floor of a channel that moved material toward the right or upper right. The lower ridge is the older channel. It was completely filled and buried beneath the surface when the upper channel formed.Click on image for larger view A regional context image shows the location of the fan with a white box. West of the fan are several valleys that fed water and sediment to the crater holding the fan (labeled "Holden NE" Crater). This map is a mosaic of daytime infrared images from the Thermal Emission Imaging System on Mars Odyssey. The contours are topography relative to Mars' zero-elevation level, derived from observations by the Mars Orbiter Laser Altimeter on Mars Global Surveyor. Sunlight illuminates the scene from the upper left. The 10-kilometer scale bar is about 6.2 miles across.Click on image for larger view Additional information about Mars Global Surveyor is online at http://mars.jpl.nasa.gov/mgs/ [ http://mars.jpl.nasa.gov/mgs/ ]. The Jet Propulsion Laboratory, Pasadena, Calif., manages the Mars Global Surveyor mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. JPL's industrial partner is Lockheed Martin Space Systems, Denver, which built and operates the spacecraft., November 13, 2003 Details in a fan-shaped deposit discovered by NASA's Mars Global Surveyor orbiter provide evidence that some ancient rivers on Mars flowed for a long time, not just in brief, intense floods. The apron of debris filling the middle of this picture from the spacecraft's Mars Orbiter Camera is a hardened and eroded distributory fan, a type of geological feature that includes river deltas and alluvial fans. Sediments transported through valleys by water on early Mars formed the 13-kilometer-long (8-mile) deposit in the distant past, when it was still possible for liquid water to flow across the martian surface. Mars Orbiter Camera team members published discovery of this feature in the online edition of the journal Science. What is important about it? First, it provides unequivocal evidence that some valleys on Mars experienced persistent flow over considerable periods of time, as rivers do on Earth. Second, because the fan is today a deposit of sedimentary rock, it demonstrates that some sedimentary rocks on Mars were deposited in a liquid environment. Third, the fan's general shape, the pattern of its channels, and its low slopes provide circumstantial evidence that the feature was an actual delta -- that is, a deposit made when a river or stream enters a body of water. If so, this landform is a strong indicator that some craters and basins on Mars once held lakes. Hundreds of other locations on Mars where valleys enter craters and basins have been imaged by the Mars Orbiter Camera, but none has shown landforms like those presented here. The picture is a mosaic of images acquired between August 2000 and September 2003. The area covered 14 kilometer (8.7 miles) by 19.3 kilometers (12 miles). North is up. Sunlight illuminates the scene from the left. The spacecraft's narrow-angle camera takes grayscale images, the color added is based on information from a camera on Mars Odyssey. The fan is in an unnamed crater that is 64 kilometers (40 miles) in diameter, at 24.3 degrees south latitude, 33.5 degrees west longitude. The crater lies northeast of a larger one named Holden Crater. The fan is a fossil landform. That is, it is an eroded remnant of a somewhat larger and thicker deposit. The originally loose sediment was turned to rock and then eroded over time to present the features seen today. The channels through which sediment was transported are no longer present. Instead, only their floors remain, and these have been elevated by erosion so that former channels now stand as ridges. The floors of former channels became inverted in this way because they were more resistant to the forces of erosion, indicating they either were more strongly cemented than surrounding materials, or they have more coarse grains (which are harder to remove), or both. Closer looks at two portions of the fan show observations critical to the story. White boxes overlaid on the image show the locations of those two areas. |
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Distributory Fan Near Holden
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PIA04869
Sol (our sun)
Mars Orbiter Camera
| Title |
Distributory Fan Near Holden Crater |
| Original Caption Released with Image |
Click on image for larger view A region near the center of the fan has a loop, the inverted floor of a former meandering stream that was cut off as the channel adjusted its course. Meanders and cut-off meanders are the prime evidence for persistent flow of water through this area sometime early in martian history.Click on image for larger view A region near the southeast edge of the fan shows inverted channels at different levels within the sedimentary deposit, indicating a long and complex history of water-related processes. One ridge crosses over another just left of the center of this frame. The top of the lower ridge is the former floor of a channel that was transporting water and sediment toward the lower right. The top of the upper ridge was once the floor of a channel that moved material toward the right or upper right. The lower ridge is the older channel. It was completely filled and buried beneath the surface when the upper channel formed.Click on image for larger view A regional context image shows the location of the fan with a white box. West of the fan are several valleys that fed water and sediment to the crater holding the fan (labeled "Holden NE" Crater). This map is a mosaic of daytime infrared images from the Thermal Emission Imaging System on Mars Odyssey. The contours are topography relative to Mars' zero-elevation level, derived from observations by the Mars Orbiter Laser Altimeter on Mars Global Surveyor. Sunlight illuminates the scene from the upper left. The 10-kilometer scale bar is about 6.2 miles across.Click on image for larger view Additional information about Mars Global Surveyor is online at http://mars.jpl.nasa.gov/mgs/ [ http://mars.jpl.nasa.gov/mgs/ ]. The Jet Propulsion Laboratory, Pasadena, Calif., manages the Mars Global Surveyor mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. JPL's industrial partner is Lockheed Martin Space Systems, Denver, which built and operates the spacecraft., November 13, 2003 Details in a fan-shaped deposit discovered by NASA's Mars Global Surveyor orbiter provide evidence that some ancient rivers on Mars flowed for a long time, not just in brief, intense floods. The apron of debris filling the middle of this picture from the spacecraft's Mars Orbiter Camera is a hardened and eroded distributory fan, a type of geological feature that includes river deltas and alluvial fans. Sediments transported through valleys by water on early Mars formed the 13-kilometer-long (8-mile) deposit in the distant past, when it was still possible for liquid water to flow across the martian surface. Mars Orbiter Camera team members published discovery of this feature in the online edition of the journal Science. What is important about it? First, it provides unequivocal evidence that some valleys on Mars experienced persistent flow over considerable periods of time, as rivers do on Earth. Second, because the fan is today a deposit of sedimentary rock, it demonstrates that some sedimentary rocks on Mars were deposited in a liquid environment. Third, the fan's general shape, the pattern of its channels, and its low slopes provide circumstantial evidence that the feature was an actual delta -- that is, a deposit made when a river or stream enters a body of water. If so, this landform is a strong indicator that some craters and basins on Mars once held lakes. Hundreds of other locations on Mars where valleys enter craters and basins have been imaged by the Mars Orbiter Camera, but none has shown landforms like those presented here. The picture is a mosaic of images acquired between August 2000 and September 2003. The area covered 14 kilometer (8.7 miles) by 19.3 kilometers (12 miles). North is up. Sunlight illuminates the scene from the left. The spacecraft's narrow-angle camera takes grayscale images, the color added is based on information from a camera on Mars Odyssey. The fan is in an unnamed crater that is 64 kilometers (40 miles) in diameter, at 24.3 degrees south latitude, 33.5 degrees west longitude. The crater lies northeast of a larger one named Holden Crater. The fan is a fossil landform. That is, it is an eroded remnant of a somewhat larger and thicker deposit. The originally loose sediment was turned to rock and then eroded over time to present the features seen today. The channels through which sediment was transported are no longer present. Instead, only their floors remain, and these have been elevated by erosion so that former channels now stand as ridges. The floors of former channels became inverted in this way because they were more resistant to the forces of erosion, indicating they either were more strongly cemented than surrounding materials, or they have more coarse grains (which are harder to remove), or both. Closer looks at two portions of the fan show observations critical to the story. White boxes overlaid on the image show the locations of those two areas. |
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