Nasa says goodbye to Mars Opportunity rover as it is sent touching final message

Nasa engineers said goodbye to the Opportunity rover with a touching final message. The little robot spent 15 years exploring the surface of Mars, sending back unprecedented amounts of information to engineers back on Earth. But months ago the signals it was sending back started to look worrying. It told Nasa its batteries were running low and it was getting dark – before it was swallowed by a dust storm that took over the entire planet. Since then, Nasa has been sending messages to the rover in the hope of waking it up and bringing it back to life.