What is a rover in space exploration?

Rovers are mobile robots sent to explore planetary surfaces, especially Mars and the Moon. They carry scientific instruments such as cameras, drills, spectrometers, and weather sensors, allowing them to examine many locations over time. The Mars rover Sojourner landed in 1997 as the first successful Mars rover, and later rovers such as Spirit, Opportunity, Curiosity, and Perseverance expanded the science dramatically. Rovers are controlled from Earth, but because of communication delays, they often have to navigate with a degree of autonomy.