This pair of images taken by the Optical Microscope on NASA's Phoenix Mars
Lander offers a side-by-side comparison of an airfall dust sample
collected on a substrate exposed during landing (left) and a soil sample
scooped up from the surface of the ground beside the lander. In both cases
the sample is collected on a silicone substrate, which provides a sticky
surface holding sample particles for observation by the microscope.
Similar fine particles at the resolution limit of the microscope are seen
in both samples, indicating that the soil has formed from settling of dust.
The microscope took the image on the left during Phoenix's Sol 9 (June 3,
2008), or the ninth Martian day after landing. It took the image on the
right during Sol 17 (June 11, 2008).
The scale bar is 1 millimeter (0.04 inch).
The Phoenix Mission is led by the University of Arizona, Tucson, on behalf
of NASA. Project management of the mission is by NASA’s Jet Propulsion
Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin
Space Systems, Denver.