Data from NASA’s MAVEN mission has revealed that Mars auroras form through a process strikingly similar to Earth’s polar lights, solving a long-standing mystery about the Red Planet’s atmospheric physics. Published in Nature Communications, the findings show that the same mechanism driving Earth’s atmospheric phenomena operates on Mars, just on a much smaller scale due to fundamental differences in the two planets’ magnetic fields.
Although NASA declared the MAVEN spacecraft unrecoverable in June 2026 following a December 2025 signal loss, the mission’s archived data continues to yield critical scientific breakthroughs. Researchers discovered that a miniature version of the Dungey cycle—the process that accelerates charged particles and generates auroras on Earth—is happening over Mars’ intensely magnetized crustal magnetic fields. This realization provides scientists with a clearer view of the physics governing Martian auroras and the planet’s interaction with the sun.
How the Dungey Cycle Powers Mars Auroras
On Earth, the Dungey cycle begins when the sun’s magnetic field lines interact with our planet’s global magnetosphere, the large magnetic bubble protecting the planet. These lines reconnect, injecting energy and mass throughout the magnetosphere and magnetotail. This process ultimately fires electrons back into the atmosphere to create brilliant auroras. The Dungey cycle drives electrical currents, accelerates the charged particles that create auroras, and controls the circulation of plasma in Earth’s magnetosphere and ionosphere.
Mars, however, lacks a global magnetic field. Earth’s magnetic field is generated by our planet’s churning core, while Mars possesses numerous miniature magnetospheres created by intensely magnetized crust scattered across the planet. These regions formed roughly 4 billion years ago when cooling lava locked in the presence of Mars’ ancient global magnetic field. That ancient field has since disappeared due to intense solar wind stripping the Martian atmosphere over billions of years.
Scientists knew magnetic reconnection was occurring at Mars, but they did not anticipate it mirroring the Dungey cycle. The MAVEN mission observed highly localized auroras over these crustal magnetic fields, similar to Earth’s auroras at the poles, but the underlying physics remained elusive until this recent study. Because Mars lacks a global field to funnel particles to the poles, these localized crustal fields act as the primary conduits for solar wind interaction, creating fragmented but intense auroral displays.
Instruments That Solved the Puzzle
To build a comprehensive picture of this Dungey-like behavior, researchers relied on several instruments aboard the MAVEN spacecraft. The Magnetometer and Solar Wind Electron Analyzer determined the magnetic configuration and derived electrical currents. Meanwhile, the Suprathermal and Thermal Ion Composition (STATIC) instrument measured plasma flows in the ionosphere.
“We really pushed the limit of STATIC to get the data we needed,” said Shaosui Xu, lead author of the study and associate research physicist at the Space Sciences Laboratory at the University of California, Berkeley. “It was the final piece to the puzzle in understanding these localized auroras.”
The realization that a Dungey-like cycle operates within these crustal magnetic fields answered how electrons are energized to create the glowing displays in the Martian atmosphere. It also demonstrates that this mechanism can function on both large and small scales, expanding our understanding of where such processes might occur elsewhere in the solar system.
Implications for Planetary Evolution and Future Missions
This discovery offers more than just an explanation for atmospheric light shows. It provides a crucial window into why Mars and Earth have evolved so differently despite being governed by the same fundamental physics. By understanding how the solar environment interacts with the Red Planet as a whole, scientists can better prepare for future robotic and crewed missions to Mars. The findings highlight the importance of studying localized magnetic fields when assessing radiation risks and atmospheric conditions for future explorers.
“This is a remarkable result that changes how we think of Martian auroras and is another important step toward understanding why Mars and Earth have evolved so differently despite being governed by the same underlying physics,” said Shannon Curry, MAVEN’s principal investigator and a research scientist at the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder. “I am incredibly proud of our team’s work on this discovery and excited to uncover new insights into the Red Planet and its evolution.”
The MAVEN mission, part of NASA’s Mars Exploration Program portfolio, has left a lasting legacy. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the mission, while Lockheed Martin Space built the spacecraft and managed mission operations. NASA’s Jet Propulsion Laboratory in Southern California provided navigation and Deep Space Network support. Although the spacecraft is no longer operational, its data remains a vital resource for the scientific community.
What Happens Next
While the MAVEN mission may have concluded its operational life, its data archive will keep scientists busy for years. Researchers will likely use these findings to refine models of the Martian atmosphere and its interaction with solar wind. This ongoing analysis will be vital for protecting future astronauts and equipment from radiation and atmospheric escape phenomena. Furthermore, identifying the Dungey cycle on a planetary scale without a global magnetic field could prompt astronomers to look for similar aurora-generating processes on exoplanets or other solar system bodies previously thought incapable of sustaining such activity.
Xu reflected on the personal significance of the breakthrough: “I remember in graduate school discussing with my advisor how the cycling of crustal magnetic fields could work at Mars. It’s incredible to be part of the team that found the answer to that question.”
As scientists continue to mine the MAVEN data, the scientific community eagerly anticipates further discoveries about the Red Planet’s atmospheric history and its dynamic interactions with the sun.
— Priya Nair, science desk, AXO News