Page 17 - (DK) Eyewitness - Mars

Antennas
Solar panels provide power
Sun sensors record
position of spacecraft
in relation to the Sun

Television camera

FIRST TO PICTURE MARS
The Mariner 4 spacecraft consisted of a magnesium frame
L
I containing a television camera, electronic equipment, and
propulsion systems. Two antennas and four solar panels
M
were mounted on top. Nitrogen gas jets at the ends of the
B
solar panels helped to orient the craft.
MARINER 4 WHIZZES BY MARS
This NASA view shows the series of images taken
by Mariner 4 as it passed Mars. A “limb” is the outer
edge of a planet’s disk. The “terminator” is the
dividing line between the part illuminated by the
Sun, and the part in shadow. Mariner 4 discovered
the atmosphere was much thinner than previously
thought, and its instruments could detect no
R magnetic field.
O
T Mariners 6 and 7
A
N The two probes of 1969 photographed 10 percent
of the Martian surface, mainly in the southern
I hemisphere. Here were many more impact craters
M and a great polar ice cap of frozen carbon dioxide
R with a temperature estimated at -190°F (-123°C).
E Information from probes 6 and 7 was limited because
T these spacecraft were “flybys,” not designed to go into
orbit. That essential and difficult maneuver was to be
achieved by Mariner 9.

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MARINER MARINER
In 1969, Mariners 6 and 7 carried out the Mariners 6 and 7 flew over heavily cratered
first dual mission to Mars, sending back 201 equatorial and south polar regions. They missed
images. Mariner 6 flew within 2,132 miles the most dramatic volcanoes and deepest
(3,431 km) of Mars. Its images suggested canyons. One important discovery from their
that erosion was at work on the rims of pictures was that canals did not exist where some
the upland craters. astronomers had hoped to find them.

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