Predictions based on 15 years of Earth-based monitoring said that the Martian atmosphere would be much colder and clearer than Viking found it to be. Mars Pathfinder results agree with Viking. Atmospheric scientists are delighted with images of clouds, especially pictures of blue clouds against the red sky. Scientists knew from Hubble Space Telescope and other observations that Mars has clouds. But they had never before seen clouds from the surface, and those images have changed thinking about the sky on Mars.
Dust devils swirl across their landing site once, twice and sometimes several times a day.
Local dust devil storm activity not to be confused with the great global dust storms due to start in November has been a surprise. Dust devils may be a big part of the reason why Mars' atmosphere is so dusty, although scientists continue to sift through photographic evidence to see whether this actually is the case. Starlight brightens the night sky more than might be expected on a planet with such a hazy atmosphere. The imaging scientists photographed stars and Mars' two moons, Phobos and Deimos. One UA member of the IMP team holds the honor of being the first astronomer ever to be clouded out on an observing run on another planet.