NASA's MAVEN spacecraft has recorded something Mars has never shown before, which is the Zwan-Wolf effect. It's a process long known in Earth's magnetosphere but now seen for the first time in a planetary atmosphere.

The findings, published in Nature Communications, came from data collected in December 2023 during a solar storm. Instead of helping deflect the solar wind as it does at Earth, the effect at Mars appears to "squeeze" the upper atmosphere, reshaping how space weather interacts with the Red Planet.

"When investigating the data, I all of a sudden noticed some very interesting wiggles," Christopher Fowler, a research assistant professor at West Virginia University in Morgantown and lead author of the study, said as quoted by NASA. "I would never have guessed it would be this effect, since it's never been seen in a planetary atmosphere before."

First identified in 1976, the Zwan-Wolf effect describes how charged particles get compressed along magnetic field lines called flux tubes. At Earth, this compression helps divert the solar wind around our protective magnetic shield.

Mars doesn't have a global magnetic field. That's why the MAVEN team didn't expect to find the effect there. Yet the spacecraft's instruments picked up telltale "wiggles" in the ionosphere, the electrically charged layer of the Martian atmosphere below about 200 km.

Source:Ndtv