The Monster Mars dust storms may have helped to flush the red planet's water

The huge dust storms of Mars, like the one that killed NASA's Rover Opportunity Researchers may have helped to permanently eradicate the ancient waters of the red planet.

In late May 2018, a dust storm began to form around Opportunity, which had been exploring the red planet since January 2004. Dust blocked the passage of the sun to the ground, preventing the solar-powered robot from recharging his batteries for weeks. Oppy has never recovered, and NASA declared the dead rover last February.

But the storm did not only affect the excavations of Opportunity near the Martian equator. By June, the maelstrom had become a global monster, covering Mars with a veil of dust.

Related: Dust storm on March 2018: How did that kill the vehicle of opportunity?

Such global storms are not terribly rare. NASA also observed them in 1971, 1977 (twice), 1982, 1994, 2001 and 2007. (Opportunity and her twin, Spirit, managed to overcome the storm of 2007, but that of 2018 was more powerful.) Recent research suggests that events highlighting the dryness and dust of Mars may have been the ones that helped the planet achieve this goal.

Billions of years ago, Mars had a thick atmosphere and a lot of liquid water; Opportunity, Spirit and their newest and greatest rover cousin, Curiosity, have discovered a lot of evidence to that effect over the years. Indeed, scientists believe that a deep ocean has probably covered about 20% of the planet's surface in the past.

Things started to change when Mars lost its global magnetic field about 4 billion years ago. With this protective barrier gone, charged solar particles stripped most of the planet's atmosphereand over time, Mars has lost the ability to support liquid water on its surface.

The new study suggests that global dust storms may have facilitated this process. The researchers used the ExoMars Trace Gas Orbiter (TGO) to track the movement of water vapor in the Mars atmosphere before and after the 2018 dust storm.

The TGO data indicate that the maelstrom has projected much higher water molecules in the Martian sky, rising from their typical elevation of about 20 kilometers to more than 80 kilometers above ground, indicated Researchers. Up there, where the air is very thin, solar radiation breaks much easier water molecules into their constituent hydrogen and oxygen atoms. These elementary components can then be lost in space.

"When you bring water into the upper parts of the atmosphere, it is so much easier to take away," co-wrote Geronimo Villanueva, co-author of the study, researcher at the center NASA's Goddard Space Flight in Greenbelt, Maryland. said in a statement.

The study, published last month in the journal Nature newspaper, also reported a confusing result: TGO spotted no sign of methane in the atmosphere of Mars, although Curiosity crossed several plumes of gas on the ground of the crater of Gale, wide of 154 km (154 km).

Astrobiologists are keen to map Mars' methane levels and understand what produces them because gas could be a sign of biological activity on the red planet.

The researchers intensively studied the 2018 dust storm on Mars, both to understand the impact of such events on the planet's climate and to better prepare for future surface missions. Dust storms pose a threat to solar-powered rovers and landing gear – a reality exemplified by Opportunity's fate. (Curiosity is nuclear-powered, so it was relatively unaffected.)

Such storms can also have repercussions. For example, Curiosity's work shows that large dust storms prevent the formation of dust devils – tornadoes of hot, dry air that can clean up compromised solar panels.

"You have to be ready to spend some time before your next dust demon goes by and cleans you up," said Scott Guzewich, NASA Goddard 's atmospheric scientist, who led the team. investigation of the dust storm of the agency, in the same statement.

Mike Wall's book on the search for extraterrestrial life, "Over there"(Grand Central Publishing, 2018, illustrated by Karl Tate), is out now. Follow him on Twitter @michaeldwall. Follow us on twitter @Spacedotcom or Facebook.