Gale crater dust storm
In June 2018, NASA's Curiosity Rover used its Mast Camera, or Mastcam, to snap photos of the intensifying haziness on the surface of Mars, caused by a massive dust storm. The rover is standing inside Gale crater looking out to the crater rim. The photos span about a couple of weeks, starting with a shot of the area before the storm appeared. NASA

In an update on the conditions prevailing on Mars, NASA has announced that the massive dust storm, which has been raging on the red planet for nearly 20 Earth days, has grown bigger than one could possibly imagine.

The tempest, first spotted on May 31, covered approximately 14 million square kilometers or a quarter of the planet nearly 10 days ago, but now it has intensified to blanket the whole world, with no sign of slowing down.

Declaring it as a “planet-encircling” dust event, NASA noted that the grainy particles making up the storm have grown significantly over the Gale crater or the location where its Curiosity rover has been operating since 2012.

The storm came to this point after expanding from the other side of the planet. It first ravaged through Perseverance valley where the agency’s oldest rover, Opportunity, had been operating and then — after affecting Opportunity’s operations — ballooned further to go all the way across toward Curiosity’s location.

This size of this storm is comparable to the one observed by the agency’s Viking I spacecraft in 1977 but it’s still smaller than the global tempest that occurred back in 2007. NASA describes it as more diffuse and patchy than other massive storms that completely obscured the planet’s surface.

At Curiosity’s location, the sunlight-blocking haze or tau has gone over 8.0, which is six to eight times thicker than normal for this time of the year on Mars. Though this is the highest ever tau measurement recorded by the rover, Opportunity witnessed a more severe case. According to the last transmission received by the agency, tau was near 11 over its location.

Due to this, most of the sunlight was blotted out and the agency was forced to suspend solar-powered Opportunity’s science operations. The rover has not been in contact with the agency for nearly 10 days, which has led mission controllers to think that the charge in its batteries has dipped below 24 volts and it has entered a low power fault mode — a sleep sort of mode wherein all the subsystem except mission clock stop working.

The clock has been programmed to wake the system to check power levels after small intervals and attempt to communicate with ground stations, which has not happened yet. The agency believes the electronics and batteries of the rover can stay warm enough to survive the storm — like it did in 2007 — but they don’t expect a transmission until the skies clear out.

That said, it is worth noting that despite facing a ravaging storm, the agency’s Curiosity rover will largely remain unaffected. It operates on nuclear-powered batteries and can run all day long and night without any issues. The engineers at NASA have said the vehicle’s instruments are not at risk, but its cameras might require more exposure time due to low lighting and dust blowing toward its optics.

The rover and the agency’s orbiters will continue to collect as much information as possible to help scientists better understand these storms and why some of them expand so rapidly and last a lot longer than others.