QUESTION:
How much data from the Pathfinder have we received altogether?

ANSWER from Bridget Landry on November 18, 1997:
Where to begin!  We have received approximately 2.6 gigabits of info from
the Pathfinder mission since landing.  This includes:

16,500+ images from the lander
550+ images from the rover
16 soil and rock elemental analyses
wind, temperature, and pressure measurments, taken some days as frequently
     as once per second

The following are the main scientific results of the mission:
  * Martian dust includes magnetic, composite particles, with a mean size
    of one micron.
  * Rock chemistry at the landing site may be different from Martian
    meteorites found on Earth, and could be of basaltic andesite
    composition.
  * The soil chemistry of Ares Vallis appears to be similar to that of the
    Viking 1 and 2 landing sites.
  * The observed atmospheric dustiness is higher than was expected from
    Earth-based microwave measurements and Hubble Space Telescope
    observations.
  * 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 its circulation.
  * Frequent "dust devils" were found with an unmistakable temperature,
    wind and pressure signature, and morning turbulence; at least one may
    have contained dust (on Sol 62), suggesting that these gusts are a
    mechanism for mixing dust into the atmosphere.
  * Evidence of wind abrasion of rocks and dune-shaped deposits was found,
    indicating the presence of sand.
  * Morning atmospheric obscurations are due to clouds, not ground fog;
    Viking could not distinguish between these two possibilities.
  * The weather was similar to the weather encountered by Viking 1; 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 1.
  * 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 absorption features
    detected in other locations on Mars.
  * The atmospheric experiment package recorded a temperature profile
    different than expected from microwave measurements and Hubble
    observations.
  * 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 kilometers and 2,000 kilometers (807 miles and
    1,242 miles).
  * 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.

Engineering milestones of the mission included demonstrating a new way of
delivering a spacecraft to the surface of Mars by way of direct entry into
the Martian atmosphere. In addition, Mars Pathfinder demonstrated for the
first time the ability of engineers to deliver a semi-autonomous roving
vehicle capable of conducting science experiments to the surface of another
planet.