The Compact Reconnaissance Imaging Spectrometer for Mars, or
CRISM,
is a visible-infrared hyperspectral imager on the Mars
Reconnaissance
Orbiter spacecraft. After having orbited Mars for one year,
CRISM has
returned over 2700 high-resolution hyperspectral images of
key areas
of the Martian surface, and completed lower-resolution
mapping of
over half of the planet. In addition it has taken nearly
3000
measurements of atmospheric opacity to track the spatial and
temporal
evolution of dust and ice clouds and trace gases. Through an
orders
of magnitude improvement in spatial resolution compared to
earlier
composional investigations from orbit, CRISM is supporting
some
hypotheses about Mars' surface and also providing new
surprises. A
major revelation is that aqueous minerals recording a wet
environment
early in Mars' history are more common and widely distributed
than
had been thought.