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The craft, using a revolutionary
air bag landing system, first 'landed', or rather impacted
the surface at a velocity of approximately 18 m/s (40mph)
before bouncing around 15 metres into the air. Bouncing another
15 times and rolling along Pathfinder finally came to rest
about 2.5 minutes later and about 1 km from the initial impact
site.
The landing site in the Ares
Vallis region is at 19.33 N, 33.55 W, and the pathfinder craft
has been named the Sagan Memorial Station.
Pathfinder returned 2.6 billion
pieces of information, including more than 1,000 images from
the lander and 550 images from the rover as well as more than
15 chemical analyses of rocks and extensive data on winds
and other weather factors.
Mission
Results:
- The possible identification of rounded
pebbles and cobbles on the ground, and sockets and pebbles
in some rocks, suggests conglomerates that formed in running
water, during a warmer past in which liquid water was stable.
- The atmospheric experiment package recorded
a temperature profile different than expected from microwave
measurements and Hubble observations. · Martian dust includes
magnetic, composite particles with a mean size of one micron.
- Dust is confirmed as the dominant absorber
of solar radiation in Mars' atmosphere, which has important
consequences for the transport of energy in the atmosphere
and it's circulation.
- Diversity of albedos, or variations in
the brightness of the Martian surface, was similar to other
observations, but there was no evidence for the types of
crystalline hematite or pyroxene absorbtion features detected
in other locations on Mars.
- Rock size distribution was consistent
with a flood - related deposit.
- The moment of inertia of Mars was refined
to a corresponding core radius of between 1.300 km and 2,600
km.
- Rock chemistry at the landing site may
be different from Martian meteorites found on Earth, and
could be of basaltic andesite composition.
- The weather was similar to that encountered
by Viking I; there were rapid pressure and temperature variations,
downslope winds at night, and light winds in general. Temperatures
were about 10 degrees warmer than those measured by Viking
I.
- Frequent "dust devils" were found with
an unmistakable temperature, wind, pressure signature, and
morning turbulence. At least one of these may have contained
dust, suggesting that these gusts are a mechanism for mixing
dust into the atmosphere.
- Morning atmospheric obscurations are due
to clouds, not ground fog. Viking couldn't distinguish between
these two possibilities.
- The soil chemistry of Ares Vallis appears
to be similar to that of the Viking I and II landing sites.
- Evidence of wind abrasion of rocks and
dune - shaped deposits was found, indicating the presence
of sand.
- The observed atmospheric clarity is higher
than was expected from Earth - based microwave measurement
and Hubble Space Telescope observations.
Still no sign of life, but
we now have rocks named after cartoon characters, which can't
be bad.
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Rocks around
the landing site were named: Yogi,
Pooh Bear, Shaggy, Scooby Doo, Barnacle Bill, Stimpy, Mermaid,
Snoopy and Casper.
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