Opportunity (MER-B)

Opportunity launched on July 7, 2003, and scored a ‘hole in one’ landing, rolling to a stop inside tiny Eagle Crater — directly beside exposed bedrock bearing hematite ‘blueberries,’ mineral proof that acidic water once soaked the plains of Meridiani. It was the first direct field evidence of persistent liquid water on ancient Mars.

Designed for 90 days, Opportunity drove for 14 and a half years and 28.06 miles — a marathon, and still the off-world driving record. It explored ever-larger craters, from Endurance to Victoria to the 14-mile-wide Endeavour, before a planet-encircling dust storm in 2018 finally starved its solar panels. Its last message was poeticized by an engineer as: ‘My battery is low and it’s getting dark.’