Last summer NASA’s Martian exploration rover Opportunity went dark as its solar panels, needed to power the golf-cart sized explorer, were covered in dust from a planet-wide dust storm. Everyone hoped that over the following months the light Martian winds and dust devils would wipe clean the dust from the solar panels and the rover could recharge its batteries, turn on its heaters, and resume contact with Earth. It hasn’t. Consequently, on Wednesday NASA called Opportunity’s mission complete. And thanks to xkcd we have a proper little farewell.

Credit for the piece goes to Randall Munroe.