The Mars Explorer is a robotic vehicle, commonly referred to as a ROVER, that is used to explore the surface of Mars. It is equipped with cameras and other scientific instruments to collect data and take pictures of the Martian terrain. The ROVER is designed to traverse the planet's surface, allowing scientists to gain a better understanding of the environment and its potential for habitability. The Mars Explorer has been used in several missions, including the Mars Pathfinder mission in 1997 and the Mars Exploration ROVER mission in 2004.