Spirit was the first rover in the NASA MER mission (Mars Exploration Rover) to have landed on Mars.
Spirit landed on 4 January 2004, twenty days before being joined by its twin, Opportunity, in the Gusev crater, thought to have contained an ancient lake in the past.
In December 2004, goethite was detected; this was an unprecedented discovery that showed that there had been water on Mars which had eroded the Columbia Hills rocks. On 20 November 2005, Spirit celebrated its first birthday on Mars.
The Spirit Rover on Martian soil