Peak solar activity sparks unprecedented ‘global auroras’ on Mars

Mars has lately been experiencing “global auroras” of unprecedented scale as a result of increased solar activity.

Auroras are caused when charged particles from the Sun interact with a planet’s magnetic field.

On Earth, it is rare to see auroras with equal ease from the equator and the poles as the planet’s magnetic field largely shields it from solar storms. But since Mars lacks an Earth-like magnetic field, auroras on the red planet can be a global phenomenon. And the phenomenon appears to have grown more frequent now during a peak in the Sun’s activity called Solar Maximum that occurs roughly every 11 years.

At Solar Maximum, the Sun is prone to releasing flares and coronal mass ejections.

“Mars is experiencing its greatest level of auroral activity in the past 10 years,” Nick Schneider from the University of Colorado’s Laboratory for Atmospheric and Space Physics told the website Space Weather.

“In February alone, there were three episodes of global auroras, an ‘aurora hat-trick’ we’ve never seen before.”

Nasa’s Maven spacecraft helped collect data on February’s glowing auroras on Mars. They were caused by the interaction of solar energetic particles, or SEPs, with the Martian atmosphere after being accelerated by shock waves within solar storms.

“Mars is currently getting hit by roughly 1 to 2 CMEs every month, bringing a hefty supply of SEPs,” Rebecca Jolitz, a member of the Maven team at UC Berkeley, said.

Astrophysicists have been trying to understand what could happen if a solar superstorm, such as the one the world experienced on 15 May 1921, struck Earth today. That storm led to fires breaking out across electricity and telegraph control rooms in several parts of the world, including the US and the UK.

It remains unclear what damage such an outburst from the Sun could cause today.

Studying auroras on Mars during Solar Maximum, which is largely unprotected by a magnetic field, could provide more insights, researchers said.

“This will give us a chance to study how solar storms affect the atmosphere of Mars, a key goal of the Maven mission. It’s the kind of fun we’ve been waiting for!” Dr Schneider said.

“I’d actually love to see the ‘big one’ at Mars this year, a large event that we can study to understand solar radiation better before astronauts go to Mars,” astrophysicist Shannon Curry, also from the Laboratory for Atmospheric and Space Physics, said.