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OFFICE OF PUBLIC INFORMATION
JET PROPULSION LABORATORY, CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA. TELEPHONE 354-5011
FOR RELEASE: SUNDAY, OCTOBER 17, 1971
Is Mars totally bleak and inhospitable to life? Or
could water still be found on the planet? What role do dust
storms play in forming Martian clouds?
These questions may be answered, at least in part,
starting November 13 (PST) when Mariner 9 goes into orbit
around Mars for a minimum 90-day study period in the National
Aeronautics and Space Administrations's most amibitous plan-
etary trip.
Space scientists hope to receive more definitive, and
perhaps encouraging, readings, from their instruments than those
received in the 1969 flybys of Mariners 6 and 7. The results of
those flights changed centuries-old concepts of Mars as a
friendly habitat for some form of life to a cold, barren planet
as hostile as Antarctica.
Mars' South Pole was shown to be much colder than
Earth's--dry-ice cold, down to -240 degrees, Fahreinheit. The
south polar cap appeared to be almost 100 per cent frozen car-
bon dioxide, with virtually no water ice. Mars' equator
registered a low of -45 degrees, F., and a high of about 65
degrees.
-more-
-2-
Only traces of Martian water vapor have been detected
by Earth-based telescopes. Aboard Mariner 9 is a water-vapor
sensitive instrument called an infrared interferometer spectro-
meter (IRIS). It is one of two infrared instruments--the other
is the infrared radiometer (IRR)--which could provide more exact
data on the temperatures and composition of Mars' surface and
lower atmosphere.
With Mariner 9 swooping to within 750 miles of the
planet, Dr. R. A. Hanel of NASA's Goddard Space Flight Center,
Maryland, IRIS team leader, says the IRIS instrument should be
able to provide clues where liquid water may exist on Mars, if
there is any. Moist areas would be of particular interest to
biologists.
The discovery of an organic compound or some member of
the carbon family would be a hopeful sign of developing life,
however primitive, on the planet. While apparently hostile to
common earthly forms of life, Mars may foster its own rugged
unearthly organisms.
Some support for this hope was indicated in 1970 exper-
iments by researchers at Caltech's Jet Propulsion Laboratory who
produced three organic compounds in the laboratory simulating
Martian soil, atmosphere and ultraviolet radiation.
The compounds (formaldehyde, acetaldehyde and glycolic
acid) were named likely to be produced by sunlight on the sur-
face of Mars. The investigators also believed these compounds
were precursors to biological molecules on the primitive Earth.
more
-3-
Final determination of life on the planet, however,
probably will have to wait for a landed system analysis later
in the 1970s.
By measuring the radiation from the surface and lower
atmosphere in infrared wavelengths, the IRIS instrument should
furnish information on the composition of the surface, on sur-
face pressures, and on atmospheric and surface temperatures.
The composition of the polar caps, particularly the
edge of the southern cap as it melts in the Martain summer, will
be another IRIS study. Surface minerals may be identified,
along with their thermal conductivity, density and temperature.
Daily temperature variations around the globe will be
recorded by the IRR. General soil temperature readings will be
taken of about 70 per cent of the planet's surface, according to
Dr. Gerry Neugebauer, Caltech physicist who heads the IRR team.
The IRR is calibrated to take midmorning and early
evening readings along the line of flight each day. Mariner 9
will orbit the planet twice daily and the changing flight paths
will afford a crIt will be summer in the south, winter in the north
during the
Mariner-go-round.
The swivel limitation of the instrument platform will
prohibit noon ornight readings, but high and low temper-
atures can be calculated from the other readings.
Other information to be sought by the IRR: Cooling
curves around the globe, and possible hot spots--perhaps vol-
canoes or radioatrs f comparatively recent origin.
more
-4-
The twored instruments will team up with Mar-
iner's two TV cameras in a special yellow cloud alert on or
about December 14. Dr. Gerard deVaucouleurs, University of
Texas astronomern member of the television experiment team,
has predicted that the bright yellow cloud will appear over the
Libya-Moeris Lacus area just north of the Martian equator.
The cloud, presumed to be a dust storm, will last for
about a week, moving at speeds up to 65 m. p. h. (100 Km) in a
southeasterly direction.
Dr. deVaucouleurs based his prediction on five pre-
vious clouds over the region observed by Earth-bound astron-
omers when Mars was in similar close proximity. On each of
these five occasions--oppositions, as astronomers call them
--since 1911, the bright yellow cloud was sighted.
Mariner's cameras and infrared instruments will be
tuned in for an exhaustive analysis of the predicted atmos-
pheric phenomenon.
The 1971 Mariner Mars project is being managed by JPL
for NASA.
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BB-#599- 10/11/71