MARS — NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft detected the Zwan-Wolf effect in Mars' ionosphere in December 2023 following a solar coronal mass ejection. The atmospheric fluctuations, described as unusual 'wiggles,' were identified as the first observational evidence of the Zwan-Wolf effect on Mars.

The Zwan-Wolf effect involves charged particles being squeezed along magnetic structures called flux tubes. Although first discovered on Earth in 1976, scientists previously believed the phenomenon could not occur on Mars due to the planet’s lack of a global magnetosphere, which results from its solidified core.

The effect was observed at an altitude of approximately 125 miles (200 kilometers) in Mars’ ionosphere. Researchers determined that a coronal mass ejection from the Sun in December 2023 intensified the effect enough to make it detectable. The Martian Zwan-Wolf effect is likely driven by a localized magnetic field at the boundary where the solar wind collides with ionospheric plasma.

"When investigating the data, I all of a sudden noticed some very interesting wiggles," said Christopher Fowler, a planetary scientist at West Virginia University. "I would never have guessed it would be this effect," he added.

Shannon Curry, a research scientist at the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder and principal investigator for the MAVEN mission, said, "Knowing how space weather interacts with Mars is essential." Changes to Mars’ ionosphere may affect orbiting spacecraft, communications equipment, and surface radiation levels.

The study describing the detection was published on May 18 in the journal Nature Communications. MAVEN has been orbiting Mars since 2014, collecting data on the planet’s upper atmosphere and its interaction with solar activity. Researchers now hypothesize that the Zwan-Wolf effect may also occur on Venus and Saturn’s moon Titan.