After a picture-perfect launch to Mars on August 4, 2007 (see fig. 1), the Phoenix mission will land near 70° N on the northern lowlands on May 25, 2008 and perform an in situ investigation of the ice layer discovered by the Mars Odyssey scientists in 2002. Mars undergoes climate change through obliquity and orbital variations on time periods of 50,000 years. By analyzing the minerals, aqueous chemistry, and grain shapes of the soil associated with the ice, Phoenix will determine whether the ice has ever melted and modified the soil properties. Since water is a necessary substance for life on Earth, a major question for the mission is whether the northern plains represent a habitable zone on Mars. Besides water, the Phoenix team will assess the organic content of the soil and ice as well as the abundances of biologically active elements. Finally, the transport of water through soils and atmosphere is measured using a Canadian meteorological station supplemented by probes to evaluate soil conductivity.