NASA's Phoenix Mars Lander, after a short trajectory maneuver, is now on course and schedule for its May 25 landing on the Red Planet. The lander launched aboard a Delta II rocket on August 4, 2007, and will have reached the surface of Mars in just over nine and a half months.

The Phoenix is one of the first ground vehicles for NASA's Mars Exploration Program. It will return valuable data on the climate and geology of Mars, furthering the ultimate goals of determining whether life exists or ever existed on Mars, and returning to us vital knowledge with which to prepare manned expeditions.

Based on data collected by the Mars Odyssey Orbiter, NASA scientists have tentatively chosen what appears to be a safe landing zone for the Phoenix craft. Several factors were key in the choice, including the overall geography of the region and data which suggests water ice lies just below the surface of the large plain at the destination.

"Our landing area has the largest concentration of ice on Mars outside of the polar caps. If you want to search for a habitable zone in the arctic permafrost, then this is the place to go," explained Peter Smith, the principle investigator for the Phoenix mission.

The proposed landing site is known as "Green Valley," and lies in the planet's northern hemisphere. The lack of large rocks to interfere with the landing and the presence of water ice makes the 62 by 12 mile ellipse targeted area an ideal choice for the mission. Experts will make the final decision on the landing zone after further scrutiny of the area by the Mars Odyssey Orbiter later this month.

The Phoenix project is led by Peter Smith at the University of Arizona, Tuscon, and is a joint project between UA, NASA's Jet Propulsion Laboratory, Lockheed Martin, the Canadian Space Agency, the University of Neuchatel in Switzerland, the universities of Aarhus and Copenhagen in Denmark, the Max Planck Institute in Germany and the Finnish Meteorological Institute.