Phoenix was the first to explore the surface of a polar region on Mars, areas rich in water-ice (right).
The spacecraft landed farther north than any previous spacecraft to land on the Martian surface.
It was the first mission in NASA's Mars Scout program.
Phoenix inherited its lander. Originally the lander was to be used for the Mars Surveyor 2001 program, but after the lander portion of that program was cancelled it was kept in a protective, controlled environment.
Phoenix's robotic arm was designed to dig trenches (right), scoop up soil and water ice samples, and deliver these samples for analysis.
The lander's Canadian laser instrument used for studying the atmosphere detected snow falling from clouds on Mars.