NASA Says Mars' Global Dust Storm Is Finally Over

NASA says the global dust storm on Mars that incapacitated its Opportunity rover has finally ended. The space agency made the determination based on tau, which is the amount of sunlight that manages to penetrate the hazy dust in the planet's atmosphere. According to the agency's latest update, the measurement is now back to normal.

NASA revealed the storm's existence early this past summer, stating in mid-June that it was one of the thickest dust storms scientists had ever observed on the Red Planet. The dust eventually blotted out the sunlight, which Opportunity rover depended on for recharging its batteries.

It didn't take long before the dust storm became global, circling the entire planet and leaving the older Mars rover unable to function. On August 1, NASA reported that the dust storm was showing signs of abating, and by August 7 the tau reading had dropped to 2.5.

NASA started listening for potential communication from Opportunity rover, soon increasing the number of times it attempted to contact the machine. Unfortunately, the space agency still has not established communication with the rover.

In its most recent update on the Mars mission, NASA revealed that Mars' tau rating is 0.8, which is a level considered normal and storm-free. The space agency previously stated that dust on Opportunity's solar panels may be inhibiting its ability to recharged, though there's no way of knowing exactly why it hasn't responded.

Experts say Mars is undergoing a windy season and that high winds may blow dust off the rover's solar panels, assuming that's the problem. If that happens — and again assuming there are no other issues — Opportunity may be able to recharge its batteries and establish communication with Earth.