NASA launched the Mars Science Laboratory probe, which carried the Curiosity Rover to Mars.
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Earth-like calcium-rich deposits were found on Mars by NASA's Curiosity Rover.
The Mars Polar Lander was launched.
NASA launched the Viking 1 planetary probe toward Mars.
Mars had a 'close encounter' with Earth at 34.8 million miles apart.
NASA's Pathfinder Space probe landed on Mars.