Mars Exploration Rovers
23 The data that has been sent back to Earth from the mission has shown that Mars was once a wet planet, and that it is geologically active, with rocks of distinct chemical compositions analysed. One mineral in particular, goethite, only forms in the presence of water.
Spirit’s mission officially came to an end in May 2011, although communication had been lost in March 2010. In May 2009 it had become stuck in soft Martian soil, and attempts to free it were unsuccessful.