Exciting new findings from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft indicate that the Zwan-Wolf effect—where charged particles are expelled through magnetic structures known as flux tubes—is also influencing Mars’ upper atmosphere. This phenomenon was previously believed to be exclusive to Earth’s magnetosphere.
An artistic rendering of the Zwan-Wolf effect on Mars observed by NASA’s MAVEN mission. Image credit: LASP/CU Boulder.
“While analyzing MAVEN data, we discovered a remarkable change,” said Dr. Christopher Fowler, a researcher at West Virginia University.
“We never anticipated this effect because it had not been documented in any planet’s atmosphere before.”
The Zwan-Wolf effect was first identified in 1976 and had only been recorded within planetary magnetospheres until now.
In contrast to Earth, Mars lacks a global magnetic field, which significantly impacts how it interacts with solar wind and space weather.
The MAVEN spacecraft detected the Zwan-Wolf effect within Mars’ ionosphere—less than 200 km above the surface—where a notable number of charged particles reside.
Mars has an induced magnetosphere, produced by solar wind interacting with its ionosphere, but this field’s size and form can vary dramatically due to large solar wind and space weather events.
This variability is what Dr. Fowler and his team observed in MAVEN data during a massive solar storm on Mars.
The team suspects that the Zwan-Wolf effect could be constantly occurring in Mars’ ionosphere but at levels undetectable by MAVEN’s instruments.
Currently, space weather phenomena appear to have intensified, allowing researchers to observe it in their findings.
Initially, the authors noticed intriguing fluctuations in the magnetic field as the spacecraft traversed the Martian atmosphere.
To clarify these observations, they conducted a more detailed analysis using multiple MAVEN instruments, including charged particle measurement capabilities in the ionosphere.
Further analysis revealed additional fascinating features within the data.
After eliminating other possibilities, they identified the Zwan-Wolf effect as the reason for the observations.
“No one anticipated this effect in the atmosphere,” Dr. Fowler remarked.
“This discovery is thrilling; it introduces complexities in physics that remain unexplored and sheds light on new ways solar and space weather can influence Mars’ atmospheric dynamics.”
“Understanding the Zwan-Wolf effect on Mars enhances our knowledge of space weather’s impact and offers fresh insights into similar phenomena on non-magnetic celestial bodies like Venus and Saturn’s moon Titan.”
“These observations underscore the need to comprehend how large-scale space weather fluctuations can lead to environmental changes on Mars, potentially affecting assets both on the planet and in its vicinity.”
“Understanding space weather’s interactions with Mars is vital,” stated Dr. Shannon Currie, a researcher at the University of Colorado Boulder’s Institute for Atmospheric and Space Physics and MAVEN’s principal investigator.
“The MAVEN team continues to analyze our dataset for new discoveries and connections between our Sun and Mars.”
For a detailed look at this research, see the study published in this week’s edition of Nature Communications.
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C.M. Fowler et al. 2026. The Zwan-Wolf effect is detected in the ionosphere of Mars. Nat Commun, 17, 4224; doi: 10.1038/s41467-026-72251-9
Source: www.sci.news
