Rotating globes from May 28 and July 1 show a global dust storm completely obscuring the surface of Mars.
Credits: NASA/JPL-Caltech/MSSS

In May 2018, Opportunity had been doing science on Mars since 2004, and there was no reason to think that the plucky rover wouldn’t carry on. Then, a dust storm hit that completely obscured the planet from view. After fine dust coated Opportunity’s solar panels, the rover apparently lost power and was declared dead by NASA in February 2019. Now, scientists think similar storms may have also delivered a coup de grace to water on Mars, stripping it from its surface for good.

At one point, Mars had a thick atmosphere and up to 20 percent of its surface was covered by liquid water, scientists figure. Around 4 billion years ago, however, Mars lost its magnetic field and with little to protect it from destructive solar winds, the red planet lost much of its atmosphere.

That left water on the surface vulnerable, and according to new observations from the ExoMars Trace Gas Orbiter (TGO), dust storms may have helped finish off the oceans and lakes. While water particles in the atmosphere normally linger at around 12 miles (20 km) in altitude, TGO noticed that the dust storms that killed Opportunity lifted H20 molecules up to 50 miles (80 km) above the ground.