This image from NASA's Phoenix Mars Lander's Optical Microscope shows a
strongly magnetic surface which has scavenged particles from within the
microscope enclosure before a sample delivery from the lander's Robotic
Arm. The particles correspond to the larger grains seen in fine orange
material that makes up most of the soil at the Phoenix site. They vary in
color, but are of similar size, about one-tenth of a millimeter.
As the microscope's sample wheel moved during operation, these particles
also shifted, clearing a thin layer of the finer orange particles that
have also been collected. Together with the previous image, this shows
that the larger grains are much more magnetic than the fine orange
particles with a much larger volume of the grains being collected by the
magnet. The image is 2 milimeters across.
It is speculated that the orange material particles are a weathering
product from the larger grains, with the weathering process both causing a
color change and a loss of magnetism.
The Phoenix Mission is led by the University of Arizona, Tucson, on behalf
of NASA. Project management of the mission is by JPL, Pasadena, Calif.
Spacecraft development was by Lockheed Martin Space Systems, Denver.
