Posted by tourdemars to Life on Mars at August 25, 2003 12:00 PM

Mars 2. Mars 3. Mars 6. Viking 1. Viking 2. Mars Pathfinder and Sojourner. Mars Polar Lander. Deep Space 2. All these spacecraft have landed—or crash-landed—on Mars since the early 1970s. In a few months, they will be joined by Spirit, Opportunity, and Beagle 2. All have brought scientific instruments seeking to understand the nature of planet Mars, and if the planet once or currently harbors life. They also all brought with them terrestrial bacteria.