NASA's Phoenix lander, part of the Mars Scout Program, made its landing on Mars in the Green Valley region on May 25, 2008. This mission was designed to assess the Martian climate and geology to understand the presence of water, vital in the search for past or present microbial life. Unlike prior missions that focused on the equatorial region of Mars, Phoenix was targeted at the northern polar area, an attractive location due to its ice-rich surface and historical evidence of water activity. The successful landing followed a complex descent sequence that began with the lander's entry into the Martian atmosphere, extending several critical stages including atmospheric braking, parachute deployment, and final rocket-powered descent, ultimately ensuring a soft touchdown.

Once on the surface, Phoenix began its operations, utilizing a suite of twelve scientific instruments to perform its analysis. These tools allowed the lander to dig through the Martian soil and ice, collect samples, and make assessments about water's past presence. The lander's key achievements included discovering perchlorate, a chemical that can be associated with the presence of liquid water, thus suggesting habitable conditions early in Mars' history. Throughout the mission, scientists were engaged in evaluating data back on Earth, providing valuable insights into the conditions that may support life.

The Phoenix mission lasted for several months, concluding operations in late November 2008 as the Martian winter set in and solar power became scarce. Despite its brief timeline, Phoenix sent back over 25,000 images and data points that have contributed significantly to our understanding of Mars. The information gathered about the planet's surface and climate has informed future missions, including the potential for human exploration, thus establishing the groundwork for ongoing studies concerning the existence of life beyond Earth.