NASA and JPL have closed the books on the Mars Opportunity rover. Designed for a 90 day mission, the little explorer-that-could made it almost 15 years. The last transmission from the rover has been translated into something a bit anthropomorphic and pensive, and variations on the above image have become Internet memes.  Someday someone will find it sitting forlornly in a pile of Martian dust, and at that point we’ll have to decide whether to bring it back to be displayed in the Smithsonian, or to create a permanent historical park on Mars.

Good job, Opportunity (you, too, Spirit and Sojourner). Rest easy, we’ll find you someday.