Nasa sends final messages to Mars Opportunity rover as it says goodbye to doomed space explorer

Nasa has sent its last message to the Opportunity Mars rover. But it doesn't expect a reply. The robot has been silent for the past eight months, disappearing amid an intense dust storm on the red planet. As the thick dust whipped up and around the rover – and across the entirety of Mars – the sunlight that powers it was blocked and its batteries ran out. Nasa has now issued a last series of recovery commands.