What was the name of NASA’s first rover to explore Mars?

Sojourner was NASA’s first rover to explore Mars.

The small six-wheeled rover reached Mars aboard the Pathfinder lander on July 4, 1997. It was designed as a technology demonstration, showing that a lightweight rover could deploy from a lander and move across the Martian surface while communicating with Earth.

Sojourner examined rocks and soil near the landing site in Ares Vallis. It used cameras and an alpha particle X-ray spectrometer to study the composition of surface materials. The rover operated for 83 Martian days, far exceeding its planned seven-day mission.

Sojourner is often confused with Spirit and Opportunity, which landed in 2004. It was much smaller than those later rovers and traveled only a short distance, but it established an important model for mobile Mars exploration.