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Altimeter of Jet Propulsion Laboratory (JPL) and Goddard Space Flight Center (GSFC) from 1998
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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? |
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Topographical Mars
| Title |
Topographical Mars |
| Explanation |
Contrasting colors trace changing elevations in this new high-resolution topographic map of Mars [ http://pao.gsfc.nasa.gov/gsfc/spacesci/pictures/mola/mars3d.htm ]. Just released [ ftp://pao.gsfc.nasa.gov/pub/PAO/Releases/1999/99-71.txt ], the data were gathered in 1998 and 1999 by the Mars Orbiter Laser Altimeter [ http://ltpwww.gsfc.nasa.gov/tharsis/mola.html#Introduction ] (MOLA) onboard the Mars Global Surveyor spacecraft. The martian topography is seen to range over 19 miles between the highest volcanic peaks (white) and the lowest regions (purple). Along with the striking difference [ http://www.msss.com/http/ps/di.html ] between the Red Planet's [ http://www.uapress.arizona.edu/online.bks/mars/contents.htm ] low northern hemisphere (top) and high southern regions, one of the most noticeable features on the map [ http://www-pdsimage.wr.usgs.gov/PDS/public/mapmaker/mapmkr.htm ] is the large blue-purple southern depression corresponding to the Hellas basin. Likely the result of an asteroid impact, Mars' deepest basin is about 1300 miles across making it one of the largest impact features [ http://antwrp.gsfc.nasa.gov/apod/ap960906.html ] in the Solar System. Explorations [ http://antwrp.gsfc.nasa.gov/apod/ap981216.html ] of MOLA's rich topographic database are expected to produce insights into water flows and the geologic history [ http://helio.estec.esa.nl/intermarsnet/redreport/node20.html ] of Mars. |
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Elevation Measurement Profil
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PIA01338
Sol (our sun)
MOLA
| Title |
Elevation Measurement Profile of Mars |
| Original Caption Released with Image |
The elevation measurements were collected by the Mars Orbiter Laser Altimeter (MOLA) aboard Global Surveyor during the spring and summer of 1998, as the spacecraft orbited Mars in an interim elliptical orbit. MOLA sends laser pulses toward the planet and measures the precise amount of time before the reflected signals are received back at the instrument. From this data, scientists can infer surface and cloud heights. During its mapping of the north polar cap, the MOLA instrument also made the first direct measurement of cloud heights on the red planet. Reflections from the atmosphere were obtained at altitudes from just above the surface to more than nine miles (approximately 15 kilometers) on about 80 percent of the laser profiles. Most clouds were observed at high latitudes, at the boundary of the ice cap and surrounding terrain. Clouds observed over the polar cap are likely composed of carbon dioxide that condenses out of the atmosphere during northern hemisphere winter. Many clouds exhibit dynamic structure probably caused by winds interacting with surface topography, much as occurs on Earth when winds collide with mountains to produce turbulence. The principal investigator for MOLA is Dr. David E. Smith of Goddard. The MOLA instrument was designed and built by the Laser Remote Sensing Branch of Laboratory for Terrestrial Physics at Goddard. The Mars Global Surveyor Mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for the NASA Office of Space Science. |
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MGS Mars Orbiter Laser Altim
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PIA00959
Sol (our sun)
MOLA
| Title |
MGS Mars Orbiter Laser Altimeter Topographic Profile of Impact Crater |
| Original Caption Released with Image |
Among the myriad of interesting landforms sampled by MOLA on its first traverse across the Red Planet on 15 September 1997 is this 13-mile (21-kilometer) diameter impact crater located at ~ 48°N. The figure shows the topography, the computed position of the spacecraft groundtrack (solid line) and the track adjusted to correct for image location error (dashed line). The topographic profile provides some of the first indications of how landscape modification has operated in Martian geologic history. The relief of the crater rim, in combination with the steepness (over 20°) of the inner crater wall, are intriguing in that most craters of this size are much more subdued. The shape of the outer ejecta blanket of the crater likely indicates impact into an H2O rich crust. Issues concerning how craters such as this can be used to understand the properties of the uppermost crust of Mars in regions where the role of water and other volatiles may be important can be addressed with the high spatial and vertical resolution topographic profiles that will be acquired by MOLA once it starts its detailed mapping of the Red Planet in March of 1998. |
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3000 Mile Laser Altimeter Pr
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PIA00958
Sol (our sun)
MOLA
| Title |
3000 Mile Laser Altimeter Profile Across Northern Hemisphere of Mars |
| Original Caption Released with Image |
Topographic profile across the northern hemisphere of Mars from the Mars Orbiter Laser Altimeter (MOLA). The profile was obtained during the Mars Global Surveyor Capture Orbit Calibration Pass on September 15, 1997 and represents 20 minutes of data collection. The profile has a length of approximately 3000 miles (5000 kilometers). The large bulge is the western part of the Elysium rise, the second largest volcanic province on Mars, and shows over 3 miles (5 kilometers) of vertical relief. This area contains deep chasms that reflect tectonic, volcanic and erosional processes. In contrast is the almost 1featureless1 northern plains region of Mars, which shows only hundreds of meters of relief at scales the size of the United States. Plotted for comparison is the elevation of the Viking Lander 2 site, which is located 275 miles (445 kilometers) west of the profile. At the southernmost extent of the trace is the transition from the northern plains to the ancient southern highlands. Characterizing the fine-scale nature of topography in this chaotic region is crucial to testing theories for how the dichotomy between the geologically distinctive northern lowlands and southern uplands formed and subsequently evolved. The spatial resolution of the profile is approximately 1000 feet (330 meters) and the vertical resolution is approximately 3 feet (1 meter). When the Mars Global Surveyor mapping mission commences in March, 1998, the MOLA instrument will collect 72 times as much data every day for a period of two years. |
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MGS MOC Coverage of Mars Pol
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PIA02310
Sol (our sun)
Mars Orbiter Camera
| Title |
MGS MOC Coverage of Mars Polar Lander Region |
| Original Caption Released with Image |
. The selection criteria were to find a place that was relatively flat and relatively smooth, but which displayed characteristics of the south polar layered materials. The inset (upper left) shows the location of the landing zone with respect to the south polar residual (year-round) ice cap. The base map used here is a mosaic of Viking Orbiter images from the U.S. Geological Survey. 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., High-resolution views of the Mars Polar Lander [ http://www.marspolarlander.com/ ] landing zone were essential to the selection of a safe place for the December 3, 1999, landing to occur. The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) took its first pictures of the landing zone in December 1997 [ http://www.msss.com/mars_images/3_9_98_release/7200/index.html ] and January 1998 [ http://www.msss.com/mars_images/3_9_98_release/9500/index.html ]. After that time, the south polar region was not accessible to the camera until June 1999, when the south polar winter was ending and the sun began to dawn on this region once again. Since the beginning of June 1999, an intense period of imaging has been conducted over the landing zone so that a safe site could be found. The final site has now been identified, and the pictures shown here give some idea of what the Mars Polar Lander will encounter a little more than three months from now. This figure shows the zone originally proposed by the Mars Volatiles and Climate Surveyor (MVACS) [ http://mvacs.ess.ucla.edu/ ] science team for the Mars Polar Lander mission, which spanned the region from 72° to 78°S latitude and 170° to 230°W longitude. The thin white boxes and lines crossing the proposed zone outline MOC images taken between the first week in June 1999 and the first week in August 1999. The longest images were taken at 12 by 18 meters (39 by 59 feet) per pixel, there are three sets of long images, each taken during a given week in June as the terminator (the line separating "night" from "day") moved south across the landing zone. Smaller swaths represent images at higher resolution. The best resolution so far achieved is about 4 meters (13 ft) per pixel, better images will be taken in September and October as the sun rises farther and the surface becomes better illuminated. This figure shows the location of the primary (blue) and secondary (white) landing ellipses, which were selected on the basis of interpretation of the MGS data, in particular data from the Mars Orbiter Laser Altimeter [ http://ltpwww.gsfc.nasa.gov/tharsis/98lander.html ] and the Mars Orbiter Camera [ http://www.msss.com/mars_images/index.html ] |
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