This animation consists of two close-up images of "Snow Queen," taken
several days apart, by the Robotic Arm Camera (RAC) aboard NASA's Phoenix
Mars Lander.
Snow Queen is the informal name for a patch of bright-toned material
underneath the lander.
Thruster exhaust blew away surface soil covering Snow Queen when Phoenix
landed on May 25, 2008, exposing this hard layer comprising several smooth
rounded cavities beneath the lander. The RAC images show how Snow Queen
visibly changed between June 15, 2008, the 21st Martian day, or sol, of
the mission and July 9, 2008, the 44th sol.
Cracks as long as 10 centimeters (about four inches) appeared. One such
crack is visible at the left third and the upper third of the Sol 44
image. A seven millimeter (one-third inch) pebble or clod appears just
above and slightly to the right of the crack in the Sol 44 image. Cracks
also appear in the lower part of the left third of the image. Other pieces
noticeably shift, and some smooth texture has subtly roughened.
The Phoenix team carefully positioned and focused RAC the same way in both
images. Each image is about 60 centimeters, or about two feet, wide. The
object protruding in from the top on the right half of the images is
Phoenix's thermal and electrical conductivity probe.
Snow Queen and other ice exposed by Phoenix landing and trenching
operations on northern polar Mars is the first time scientists have been
able to monitor Martian ice at a place where temperatures are cold enough
that the ice doesn't immediately sublimate, or vaporize, away.
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.