The Opportunity Rover was a robotic rover designed to explore the surface of Mars. Launched by NASA in July 2003, it landed on the Martian surface in January 2004. Its primary mission was to search for signs of past water and to study the planet's geology. Opportunity operated for nearly 15 years, far exceeding its expected 90-day mission. During its time on Mars, Opportunity traveled over 28 miles (45 kilometers) and sent back more than 217,000 images. The rover made significant discoveries, including evidence of ancient water and unique rock formations. It officially ceased communication in June 2018 after a massive dust storm.