2001 SPACE SCIENCE VIDEOTAPES |
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Tape Title | Record ID |
Date Produced | TRT: |
Synopsis |
| SKI MARS! LASER ALTIMETER PROVIDES FIRST
MEASUREMENTS OF SEASONAL SNOW DEPTH ON MARS | G01-083 | 12/06/01 |
00:20:42 | A global view of how Mars changes with
the seasons has been provided by extremely precise observations from
two investigations on NASA's Mars Global Surveyor (MGS) spacecraft.
Elevation and gravity measurements of Mars from MGS have been used to
measure seasonal changes in the thickness of seasonal frost deposits
and to provide the first direct measurement of their density. The
observations were obtained from the Mars Orbiter Laser Altimeter
(MOLA) and the spacecraft's radio tracking system. The results are
to be published in the December 7, 2001 issue of Science.
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TAPE CONTENTS: |
| ITEM (1): Mystery of the
Martian Snow - Over the course of a Martian year, which
consists of 687 Earth days, as much as a third of Mars' tenuous
carbon dioxide (CO2) atmosphere "freezes out" during the winter in
the northern and southern hemispheres. For years, scientists
wondered how the caps changed during the year. How much carbon
dioxide 'snow' is deposited each season? Are the frost deposits
more like snow or more like ice? What role do the ice caps play in
seasonal changes on Mars?
This sequence was generated using the 3-D topography generated from
the MOLA instrument. The scientists ten use the topography in a
simulated flight over the Martian surface.
Courtesy: NASA
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| ITEM (1a): The Colors of
Mars - Color Chart - MOLA Color Table - Scientists use a
color to help them better represent the surface features of Mars. In
the preceding sequences, red and white colors are used to indicate
higher relative altitudes and blue colors are used to for lower
relative altitudes. (Note that some of the sequences use a
orange-brown "true" color overlay which were generated from mosaics
from the Viking mission or the MOC camera on the MGS.)
Courtesy: NASA
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| ITEM (2): Martian Snow Depth
Revealed - Scientists made precise measurements from the
orbiting laser over the course of the Martian year to create a
portrait of the changing depth of frozen carbon dioxide. The MOLA
results show that a maximum of 1.5 to 2 meters of frozen material are
deposited during the Martian winter. During the summer, the frozen
CO2 evaporates and returns to the atmosphere.
Courtesy: NASA
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| ITEM (3): Cloud
Clues - Scientists were also able to track elusive Martian
clouds linked to the frozen deposits. The thin lines in these images
are the tracks of the laser bouncing off of the clouds. By rapidly
viewing many of the cloud tracks over time, scientists can see how
the range of the clouds (white overlay) change during the Martian
year. The results will allow a better understanding of the Martian
atmosphere, which will improve the ability to target future landers.
Characterizing the present-day behavior of CO2 is a necessary first
step towards understanding past climates on Mars.
Courtesy: NASA
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| ITEM (4): Martian Snow -
Fluffy Powder, or Ice? - The group also measured miniscule
changes in the gravity field of Mars due to the seasonal changes
carbon dioxide, which allowed them to make the first measurement of
the density of surface frost deposits. The scientists determined
that snow on Mars is denser than it is on Earth, being more ice-like
than powdery.
Courtesy: NASA
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| ITEM (5): Mars South Pole
Mesas and Pits in Frozen Carbon Dioxide (MOC2-298) JPL
Courtesy: NASA
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| ITEM (6): Evidence of Recent
Climate Change on Mars (MOC2-297) JPL
Courtesy: NASA
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| ITEM (7): Animation of the
Mars Global Surveyor - The MOLA Instrument is carried on the
Mars Global Surveyor. NASA's Jet Propulsion Laboratory manages the
MGS mission for NASA's Office of Space Science, Washington, D.C.
Courtesy: NASA
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| ITEM (8): B-Roll of MOLA
team members Dr. David Smith and Dr. Maria Zuber
Courtesy: NASA
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| ITEM (9): Interview Excerpts With:
- Dr. Maria Zuber, MOLA Deputy Principal Investigator,
Massachusetts Institute of Technology
Dr. David Smith, MOLA Principal Investigator,NASA Goddard Space Flight Center
Courtesy: NASA
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Space Science Gallery