The dust storm of March 2018 intensifies

The Martian dust storm that slept the Opportunity rover early June has intensified to become a planetary dust event, or PEDE, that would cover both North America and Russia if it was on Earth. Although its current location is far from Opportunity, the Curiosity rover (who is currently studying Gale Crater) has captured the growing impacts of the storm in a broken selfie on June 15th.

The dust storm, though not unexpected, is a bit premature. Fast approaching the opposition in July, with its closest approach to the Earth occurring shortly thereafter. This configuration normally offers excellent views of the surface features of the planet, which will certainly not be the case if it is buried under a thick cloud of dust. Regional dust storms are common, but scientists are not quite sure what is causing them to become PEDEs. The planet's dust storms are usually caused by global warming as the planet approaches its closest point to the Sun. Temperature contrasts generate winds that capture and scatter fine particles of surface dust. As the polar ice caps melt, the extra carbon dioxide in the atmosphere increases the surface pressure and suspends the particles in the air, sometimes in clouds reaching up to 60 km of height.

Curiosity captures this sequence of daily images As a result of the decline of available sunlight, dust has blocked the sky, operators believe that the 14-year-old Opportunity robot is extinguished as a result of a drop in sunlight. power failure (which simply means that its solar panels can not generate enough energy to recharge its batteries). The mobile is designed to keep counting time, waking periodically to determine if the sky has cleared and the solar panels have filled the batteries. While Opportunity has survived dust storms in the past, the intensity and expected longevity of it could be a problem. A defect in the clock of the mission could make the recovery of the mobile more difficult, but not impossible. And if time passes too much, the robot's batteries can discharge completely, affecting their long-term capacity.

According to the Mars Exploration Rovers website, "the plan is to continue every day until the sky clears up … The team does not expect to hear anything from "Opportunity until there was a significant reduction in the storm and the atmospheric opacity associated with the rover site."

Curiosity – which relies on a nuclear battery rather than solar power – continues to work, albeit under a thick cloud of dust already measured with greater opacity than ever before. When his last selfie was taken, the haze around Curiosity was already six to eight times thicker than normal for this period of the Martian year. The rover engineers believe that the impact of the storm on the rover's hardware is minimal even though the rover is pointing his camera down after each use to minimize the effects of dust on the optics.

Although the storm may diminish spectator enjoyment of this Mars opposition, it will improve our understanding of how such storms occur, evolve, and impact the planet. With rovers at the surface and orbits rotating around the sky, Mars is under constant surveillance with instruments providing detailed and high-resolution views of this global event.