An artist's depiction of what one of the MER rovers may look like on the surface of Mars. Click on image for full size (68K JPEG ) Image courtesy NASA/JPL

NASA's Mars Exploration Rover (MER) mission has sent two robotic rovers to the surface of Mars. The two separate spacecraft are exploring sites named Gusev Crater and Meridiani Planum that are on opposite sides of Mars. The rovers are designed primarily as geological surveyors, with a special focus on finding signs of past or current deposits of water on or near the Martian surface. Many types of rocks that form in the presence of water contain clues that reveal that water was around when they formed. The rovers are looking for such rock types, such as sedimentary deposits formed in lakes or seas and the mineral gray hematite.

The twin MER missions were launched in June and July of 2003. The spacecraft landed on Mars in January 2004. The rovers are expected to have an operational lifetime of about 90 days on the surface of the Red Planet. The rovers have been given names: "Spirit" and "Opportunity".

NASA's Mars Exploration Rover (MER) mission has sent two robotic rovers to the surface of Mars. The two separate spacecraft are exploring sites on opposite sides of Mars. One rover is exploring Gusev Crater. The other rover is exploring Meridiani Planum. Scientists think there is a good chance that there was water at each of these sites in the past. Places that have or had water are the best places to look for signs of life. The rovers have special instruments to look for signs of water.

The twin MER missions were launched in June and July of 2003. They made it to Mars in January 2004. The two rovers have been given names. The first is named "Spirit" and the second is called "Opportunity".

NASA's Mars Exploration Rover (MER) mission has sent two robot rovers to Mars. The two robots landed at different places on Mars. The places are called Gusev Crater and Meridiani Planum. Scientists think there might have been water at each of the places in the past. Places that had water are the best places to look for signs of life. The rovers have special instruments to look for signs of water.

The two MER spacecraft blasted off in June and July of 2003. They got to Mars in January 2004. The two rovers have been given names. The first is named "Spirit" and the second is called "Opportunity".