A Rover Family Portrait

NASA’s Perseverance rover carried an Easter egg onboard: A family portrait showing the evolution of our wheeled avatars on the Red Planet. What have these rovers taught us?

Mars rover family portrait aboard NASA’s Perseverance rover. Image credit: NASA/JPL-Caltech

Five rovers have successfully landed on the surface of Mars to date, all from NASA: Sojourner, Spirit, Opportunity, Curiosity, and Perseverance. Each one of these has built upon the knowledge gained from its predecessors to help us paint a more complete picture of the history of water—and potentially life—on Mars.

Sojourner

View of Sojourner driving around in the martian dirt (“regolith”) on the 13th day of the Pathfinder mission in July of 1997. Image credit: NASA/JPL-Caltech

Launched in 1996 aboard the Pathfinder lander, Sojourner was humanity’s first rover sent beyond the Moon. The lander-rover combo was designed to be a technology demonstration to see if we could land and operate a rover on another planet. Its destination: The mouth of Ares Vallis, a feature that was interpreted from satellite images to be a massive outflow channel carved by catastrophic floods of liquid water in the ancient martian past. Pathfinder and Sojourner’s analyses of the shapes of the rocks at the landing site supported the hypothesis that the rocks were transported by floods. This tied into formulating the mission goals for the next pair of rovers…