Scientists on NASA’s MAVEN (Mars Atmosphere and Volatile Evolution) mission have discovered a key piece of the puzzle in understanding certain types of auroras on Mars, discovering that they form similarly to terrestrial auroras.
Results published Thursday in Nature Communications show that the same mechanism that circulates and catapults charged particles into Earth’s atmosphere is happening on Mars on much smaller scales due to differences in the two planets’ magnetic fields.
The MAVEN spacecraft, in orbit around Mars, experienced a signal loss with ground stations on Earth on December 6, 2025. On June 3, NASA declared the mission terminated after finding the spacecraft unrecoverable. However, data from the mission is still used to inform NASA science and future missions to Mars.
When the Sun’s magnetic field lines approach Earth’s magnetosphere, the large magnetic bubble that protects the planet, they can reconnect and inject energy and mass throughout Earth’s magnetosphere and magnetic tail, ultimately shooting electrons back into the atmosphere to generate Earth’s auroras. This process, called the Dungey cycle, drives electrical currents, accelerates charged particles that create auroras, and controls the circulation of plasma in Earth’s magnetosphere and ionosphere.
This new study shows that a miniature version of the Dungey cycle is occurring over the strong magnetic fields of the Martian crust, giving scientists better insight into the physics of Martian auroras.
“We knew magnetic reconnection was happening on Mars, but we didn’t expect it to be like the Dungey cycle,” said Shaosui Xu, lead author of the study and associate research physicist at the Space Sciences Laboratory at the University of California, Berkeley.
Mars does not have a global magnetic field like Earth. Earth’s magnetic field is created by our planet’s churning core, while Mars has numerous miniature magnetospheres arising from an intensely magnetized crust spread across the planet. These regions formed about 4 billion years ago when lava cooled in the presence of Mars’ ancient global magnetic field, which has since disappeared due to the intense solar wind that stripped the planet’s atmosphere.
The MAVEN mission has observed very localized auroras over these fields of the Earth’s crust, similar to Earth’s auroras at the poles, but it was not until now that scientists were able to fully understand the physics of how they form. The study used several instruments aboard the MAVEN spacecraft to build a picture of Dungey-like behavior: the Solar Wind Electron Analyzer and Magnetometer instruments, which were used to determine the magnetic configuration and derive electrical currents, and the STATIC (Suprathermal and Thermal Ion Composition) instrument, which was used to measure plasma flows in the ionosphere.
“We really pushed the limit of STATIC to get the data we needed,” Xu said. “It was the last piece of the puzzle in understanding these localized auroras.”
The understanding that a Dungey-like cycle was occurring within these magnetic fields of the Earth’s crust answered the question of how electrons were energized to create auroras. It also shows that a Dungey-like mechanism can occur on both large and small scales, providing more information about where in the solar system this process might be taking place.
“This is a remarkable result that changes the way we think about Martian auroras and is another important step towards understanding why Mars and Earth have evolved so differently despite being governed by the same underlying physics.” said Shannon Curry, MAVEN principal investigator and 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 about the Red Planet and its evolution.”
By discovering more about this process, scientists are also gaining a better understanding of how the solar environment interacts with the Red Planet as a whole, which is essential for future robotic and manned missions.
“I remember in graduate school discussing with my advisor how the cycling of Earth’s crustal magnetic fields might work on Mars,” Xu said. “It’s amazing to be part of the team that found the answer to that question.”
The MAVEN mission is part of NASA’s Mars Exploration Program portfolio. The mission’s principal investigator works at the University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics, which is also responsible for managing scientific operations and public outreach and communications. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the MAVEN mission. Lockheed Martin Space built the spacecraft and is responsible for mission operations. NASA’s Jet Propulsion Laboratory in Southern California provides navigation and support for the Deep Space Network.
For more information about NASA’s MAVEN mission, visit:
https://science.nasa.gov/mission/maven/
Karen Fox/Alana Johnson
Headquarters, Washington
240-285-5155 / 202-672-4780
karen.c.fox@nasa.gov / alana.r.johnson@nasa.gov
Lonnie Shekhtman
NASA Goddard Space Flight Center, Greenbelt, Maryland.
lonnie.shekhtman@nasa.gov