A Recent Solar Storm Even Had an Impact on Mars

Planet Earth is in for some amazing geomagnetic storms in the next year or so. That’s because it’s in a period of peak activity called “solar maximum” (solar max, for short). But, what happens at other planets, especially Mars, during this time? Mars mission scientists got a sneak peek at the effect of a major solar storm thanks to one hitting the Red Planet on May 20th, 2024.

During that event, the Curiosity Mars rover’s Radiation Assessment Detector (RAD) measured a very sharp increase in radiation during the solar storm. At the same time, the navigation camera captured views of a wind gust stirring up surface dust. The radiation count was the highest the instrument has seen since the rover landed on Mars. In space, the Mars Odyssey orbiter’s star camera also experienced a shower of solar particles. The bombardment knocked the camera out for a short time. During its recovery time, the spacecraft continued collecting data. That included information about the x-rays, gamma rays, and other charged particles streaming from the Sun.

NASA’s MAVEN spacecraft also collected data about the bombardment from the May 20th event. “This was the largest solar energetic particle event that MAVEN has ever seen,” said MAVEN Space Weather Lead, Christina Lee of the University of California, Berkeley’s Space Sciences Laboratory. “There have been several solar events in past weeks, so we were seeing wave after wave of particles hitting Mars.”

What Protects Planets from the Solar Storm?

There’s not much we as a species can do to protect our planet from a solar storm. However, we’re lucky—we have a strong magnetic field to ward off the worst solar outbursts. Mars is not so lucky. It doesn’t have as much of a magnetic field to ward off the deadly radiation. Space weather experts estimated that if someone had been standing on the Martian surface during that storm, they would have been irradiated with the equivalent of 30 chest X-rays in just a short time.

That storm, and others have sparked auroras on Mars (as well as on Earth). A storm earlier in May sparked off major auroral displays on Earth on May 10-11, but otherwise didn’t severely damage any vital systems. Solar storms, however, do offer a good chance for scientists to track the Sun’s outbursts as they rampage across the Solar System. The data they get gives more insight into solar activity. However, the data from the Mars missions also provides a chilling look at just what kind of risky environment Mars is for future explorers.

Sheltering from the Solar Storm on Mars

Here on Earth, if we have plenty of notice of a solar outburst, people can get ready for the inevitable damage a solar storm can cause. For example, satellite operators can prepare their assets to protect them. NASA can advise astronauts in space to take shelter and other precautions. Ground-based power and telecommunications operators have plans in place to protect their systems from the tremendously strong ground currents that get stirred up by solar storms.

But, what if you’re on your way to Mars when a storm hits? Or, you’re actually ON Mars? Those questions occupy a lot of study time at NASA and other space agencies. People in space, whether orbiting Earth or en route to the Moon or Mars can take shelter inside their craft. In those cases, they have to depend on hardened shelters to keep them safe. But, on Mars, things are different. There’s no strong magnetic field to ward off the strong particles from the Sun. Inhabitants will have to take shelter, according to Don Hassler of Southwest Research Institute’s Solar System Science and Exploration Division.

“Cliffsides or lava tubes would provide additional shielding for an astronaut from such an event. In Mars orbit or deep space, the dose rate would be significantly more,” Hassler said.“I wouldn’t be surprised if this active region on the Sun continues to erupt, meaning even more solar storms at both Earth and Mars over the coming weeks.”

What Happened on May 20th?

The storm that Curiosity recorded began with an X12-class solar flare. That’s one of the strongest solar flares recorded and, if it had been aimed at Earth, could have caused some major damage. As it turns out, Mars was in the pathway of that flare and a subsequent coronal mass ejection. It launched a cloud of charged particles through space. When the outburst from the flare and the CME arrived at Mars, it triggered auroral displays on the Martian night side. At the same time, the outbursts showered the surface with charged particles. If someone had been on Mars and working outside a shelter, they would have been dosed with the equivalent of 30 chest X-rays. That’s not a deadly exposure, but over time if someone experienced many such events, the damage to their body would add up.

Luckily, the storm did no damage to Curiosity or any of the spacecraft at Mars. But, that won’t always be the case, and mission planners can use the data from this storm and others to figure out how best to protect future explorers.

For More Information

NASA Watches Mars Light Up During Epic Solar Storm
NASA Curiosity Mars Mission