The term 'Robot on Mars' refers to a robotic ROVER, which is a type of robot designed to explore the surface of Mars. The term 'ROVER' is often used to refer to these robots, which are typically equipped with cameras, sensors, and other instruments to collect data about the planet's environment. The most famous example of a ROVER is the Curiosity ROVER, which was launched in 2011 and has been exploring the Martian surface ever since.