An intense global dust storm on Mars is now beginning to clear, raising hopes that NASA's Opportunity rover will wake up and start talking to Earth again.
Opportunity has not been heard from since June 10, when the Red Planet became enveloped in a global dust storm that dramatically reduced the amount of sunlight available to the rover's solar panels. Since then, NASA has been patiently waiting for the storm to die out, so they can try to contact the rover again.
The storm is now starting to lessen, and when it reaches a tau level of 1.5 – a measure of the amount of dust in the sky – NASA plans to start sending commands to the rover in the hope that it will have woken up. The rover will have 45 days to respond, and if it doesn’t it will essentially be declared dead.
"The Sun is breaking through the haze over Perseverance Valley, and soon there will be enough sunlight present that Opportunity should be able to recharge its batteries," said John Callas, Opportunity project manager at NASA’s Jet Propulsion Laboratory (JPL), in a statement.
“Assuming that we hear back from Opportunity, we will begin the process of discerning its status and bringing it back online."
Opporunity landed on Mars in 2004, along with its twin Spirit rover, and has far exceeded its original 90-day lifetime. Spirit ultimately succumbed to the Martian weather in 2010, but Opportunity had been going strong until now.
This dust storm on Mars has been one of the biggest ever seen, but it is “finally coming to a close” according to Mars Reconnaissance Orbiter (MRO) project scientist Rich Zurek. That spacecraft is being used to watch the site near the rover to see when it has become clear enough to expect a signal.
Some have bemoaned the 45-day window, saying it is not enough time to give Opportunity to phone home. If the rover doesn’t respond in this window, NASA will only passively listen out for the rover for several months afterwards, in the event that a random weather event like a dust devil cleans its solar panels and allows it to come back to life.
While Opportunity was expected to survive this dust storm, with temperatures not predicted to drop low enough to cause it problems, there is always the possibility that the worst has happened. All we can do now is wait and hope that the rover has ridden out the storm, ready to continue its adventures on Mars.
If you want to be more active, the hashtag #SaveOppy is also making the rounds on Twitter to make the case to NASA to listen for longer than 45 days. Fingers crossed that won't be necessary.