The tilt of Mars' spin axis (obliquity) varies cyclically over hundreds of
thousands of years, and affects the sunlight falling on the poles. Because
the landing site of NASA's Phoenix Mars Lander is so near the north pole,
higher sun and warmer temperatures during high obliquity lead to warmer,
more humid surface environments, and perhaps thicker, more liquid-like
films of water in soil.
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.
