NASA launched two robotic geologists on their way to Mars during the summer of 2003. These rovers will explore two different locations on Mars. They will use a combination of 9 cameras to determine the history of water, type of rocks, weather conditions, and other features of their landing area. The rovers are expected to roam the surface of Mars for at least 90 days. Almost the entire spring semester of 2004! The Mars Exploration Rovers, named Spirit and Opportunity, are incredibly complex. They are about the size of an old-fashioned metal teachers desk and their eyes (panoramic cameras) are at the height of a typical 5th grade student! Spirit and Opportunity were built at NASA’s Jet Propulsion Laboratory near Los Angeles, California.