1999 SPACE SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| FIRST GLOBAL 3-D VIEW OF MARS REVEALS DEEP BASIN AND PATHWAYS FOR WATER FLOW | G99-046 | 5/27/99 | 00:20:10 | An impact basin deep enough to swallow Mount Everest and surprising slopes in Valles Marineris highlight a global map of Mars that will influence scientific understanding of the red planet for years. Generated by the Mars Orbiter Laser Altimeter (MOLA), an instrument aboard NASA's Mars Global Surveyor, the high-resolution map represents 27 million elevation measurements gathered in 1998 and 1999. The most curious aspect of the topographic map is the striking difference between the planet's low, smooth Northern Hemisphere and the heavily cratered Southern Hemisphere, which sits, on average, about three miles (five kilometers) higher than the north. |
TAPE CONTENTS: |
| COLOR SCALE AND 3-D INFORMATION
Some of the sequences begin with a "natural color" image mosaic from the Viking orbiters draped over the 3-D extruded MOLA data. The false colored MOLA images use two techniques to illustrate the 3-D martian terrain. The average equatorial height is taken as zero and is colored yellow; warmer colors (orange-red-brown-white) denote higher topography and cooler colors (green-blue-indigo) denote lower. The data has also been rendered in 3-D, with the elevation multiplied by a factor of 5.
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| ITEM (1): GLOBAL VIEWS - MARS GLOBE - Generated by an instrument aboard NASA's Mars Global Surveyor spacecraft called the Mars Orbiter Laser Altimeter (MOLA), the high-resolution map represents 27 million measurements of elevation gathered during March-April 1999 and the spring and summer of 1998.
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| ITEM (2): GLOBAL VIEWS - FLAT MAP - The topographic map illustrates the striking difference between the planet's low, smooth northern hemisphere and the heavily cratered southern hemisphere which sits on average about 3 miles (5 km) higher than the north. The full range of topography on Mars is about 19 miles (30 km), one and a half times the range of elevations found on Earth.
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| ITEM (3): HELLAS BASIN - The Hellas impact basin in the southern hemisphere of Mars is the largest impact crater in the solar system at 1,300 miles (about 2000 km) across. |
| ITEM (4): HELLAS BASIN - FLY AROUND - The basin is surrounded by a ring of topography that rises 1.5 miles (about two km) above the surroundings and stretches out to 2,500 miles (4,000 km) from the basin center. This ring of material, likely thrown out of the basin during the impact of an asteroid, has a volume equivalent to a 2.6-mile (4 km) thick layer spread over the continental United States, and it contributes significantly to the high topography in the southern hemisphere.
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| ITEM (5): VALLES MARINERIS - Valles Marineris is a canyon that stretches about 1850 miles (3,000 km) and its deepest point it is 5 miles (8 km) deep. The new data show that the eastern part of the vast Valles Marineris canyon slopes away >from nearby outflow channels, with part of it lying a half-mile (about 1 km) below the level of the outflow channels.
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| ITEM (6): THARSIS RIDGE - A cluster of four enormous volcanoes can be seen in this flyby of the Tharsis region. The most amazing of these giant volcanoes is Olympus Mons which rises about 15 miles (24 km) above the surrounding plains.
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| ITEM (7): LONG DOWNHILL RUN - The difference in elevation between the hemispheres results in a slope from the south pole to north pole that was the major influence on the global-scale flow of water early in martian history. Scientific models of watersheds using the new elevation map show that the northern hemisphere lowlands would have drained three-quarters of the martian surface.
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| ITEM (8): POLAR REGIONS - The current water inventory of Mars can be estimated using the new data about the south polar cap and information about the north pole released last year. While the poles appear very different from each other in visual images, they show a striking similarity in elevation profiles. Based on understanding of the north pole, this suggests that the south pole has a significant water ice component, in addition to carbon dioxide ice. The concentric lines around the poles are artifacts from the preliminary rendering.
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| ITEM (9): NORTH POLE REGION - Previously released November, 1998
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| ITEM (10): LANDING SITE - MARS POLAR LANDER - The MOLA data will also help engineers assess the area where NASA's Mars Polar Lander mission will set down on December 3, and aid the selection of future landing sites.
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| ITEM (11): MOLA / MARS GLOBAL SURVEYOR ANIMATION - During the ongoing Mars Global Surveyor mission, the MOLA instrument is collecting about 900,000 measurements of elevation every day. MOLA 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 the Jet Propulsion Laboratory, Pasadena, CA.
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| ITEM (12): INTERVIEW EXCERPTS WITH DR JIM GARVIN, MOLA SCIENCE TEAM, NASA GODDARD SPACE FLIGHT CENTER
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