The MER 2 rover successfully landed on Mars in January 2004 and conducted scientific exploration of the planet for over 6 years, vastly exceeding its planned 90-day mission duration. Equipped with cameras, spectrometers, and other instruments, MER 2 analyzed rock and soil samples to learn about Mars' geology and climate, discovered signs the planet was once warmer and wetter, and helped pave the way for future robotic and human exploration.