How long was Opportunity supposed to last

After more than 14 years driving across the surface of Mars, the NASA rover Opportunity has fallen silentmarking the end of a defining mission to another world.

At a press conference at the Jet Propulsion Laboratory in Pasadena, California, NASA bid farewell to the rover it placed on Mars on January 25, 2004: before Facebook, before the iPhone, and even before some of the scientists now in charge of it graduated high school. In its record-breaking time on Mars, the rover drove more than 28 miles, finding some of the first definitive signs of past liquid water on the red planet's surface.

With this mission, more than other robotic missions, we have made that human bond, so saying goodbye is a lot harder. But at the same time, we have to remember this phenomenal accomplishmentthis historic exploration we've done, says John Callas, the project manager for the Mars Exploration Rovers mission. I think it'll be a long time before any mission surpasses what we were able to do.

NASA had not heard from the rover since June 2018, when one of the most severe dust storms ever observed on Mars blotted out much of the red planet's sky and overtook the solar-powered rover. Initially, the storm didn't give the team pause. From about November to January, the red planet saw seasonal winds strong enough to wipe accumulated dust from Opportunity's solar panels, which is one of the major reasons the rover lasted so long in the first place. But when...