Time is running out for NASA’s Opportunity rover. A dust storm that has been raging on Mars since early June is starting to subside, potentially giving the rover enough sunlight to charge its batteries, but NASA has set a 45-day deadline before it gives up trying to wake it.

The Opportunity rover is run entirely on solar power, so a dust storm like this one , which has blocked out upwards of 99 per cent of sunlight on the surface, can be catastrophic. The last signal received from Opportunity was on …