In CARS ON MARS readers can follow the course of NASA’s Mars Exploration Rover (MER) mission as twin rovers Spirit and Opportunity explore the Red Planet. Learn how scientists determined that there was once water on Mars and how the Earthbound NASA team resolved problems with the rovers from afar in order to prolong the mission, which continues today. The author provides insight into scientists’ quest to discover whether life may have or still might exist on Mars. Back matter includes glossary, source notes, and resources.