For the past five decades, Mars has been a focus of planetary exploration. NASA’s Mars Pathfinder mission delivered the first rover, Sojourner, which proved that robotic mobility on another planet was possible and laid the groundwork for more ambitious missions. The Mars Exploration Rovers, Spirit and Opportunity far exceeded expectations. They traveled kilometers across the Martian surface, analyzed diverse rocks and soils, and provided clear evidence that liquid water once flowed on Mars—making it a more habitable world in the past.

NASA’s next rover, Curiosity, carried a more advanced laboratory. It showed that Gale Crater once hosted a long-lived lake environment with the essential chemical ingredients for supporting life, though no direct evidence of organisms has yet been found. Curiosity continues to climb up layered rocks there, recording Mars’ environmental transition from wetter ancient conditions to the drier planet seen today.

Most recently, the Perseverance rover has been collecting samples of ancient rocks for eventual return to Earth. Perseverance also flew the Ingenuity helicopter—the first powered flight on another planet—demonstrating new technologies for future exploration.

Together, these rover missions reveal Mars as a planet with a dynamic history and highlight the next steps: Mars Sample Return and, ultimately, human exploration.