This view from the Surface Stereo Imager on NASA's Phoenix Mars
Lander shows the trench informally named "Snow White." This image
was taken after a series of scrapings by the lander's Robotic Arm on
the 58th Martian day, or sol, of the mission (July 23, 2008). The scrapings
were done in preparation for collecting a sample for analysis from a hard
subsurface layer where soil may contain frozen water.
The trench is 4 to 5 centimeters (about 2 inches) deep, about 23
centimeters (9 inches) wide and about 60 centimeters (24 inches) long.
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.