Opportunity

Opportunity (MER-B) was the most successful Mars rover in terms of longevity and distance. Landing in the small Eagle Crater on Meridiani Planum, it immediately found hematite spherules (“blueberries”) indicating ancient water. Over nearly 15 years, it traveled a record 45.16 km — completing an extraterrestrial marathon — and explored multiple craters including Endurance, Victoria, and the massive Endeavour crater. Opportunity was finally silenced by a planet-encircling dust storm in June 2018, and NASA declared the mission complete on February 13, 2019.