Predicting Martian aurora to safeguard future explorers

Predicting Martian aurora to safeguard future explorers
by Robert Schreiber
Berlin, Germany (SPX) Sep 17, 2025

Planetary scientists report progress in predicting when the Martian night sky will glow with green aurora, building on new visible-light images captured by NASA's Perseverance rover.

The rover first recorded a ground-level aurora in 2024. Now, at the Europlanet Science Congress - Division of Planetary Science meeting in Helsinki, Dr Elise Wright Knutsen of the University of Oslo has shared a second observation and the predictive methods behind it.

"The fact that we captured the aurora again demonstrates that our method for predicting aurorae on Mars and capturing them works," said Knutsen, who also led science operations for the first detection.

Aurorae occur when solar wind particles from coronal mass ejections (CMEs) collide with atmospheric molecules, producing light. On Mars, oxygen atoms emit a distinctive green glow visible across the entire nightside because the planet lacks a global magnetic field to confine particles to polar regions.

Such radiation poses risks for astronauts, making reliable forecasting vital. However, predicting Martian aurorae is difficult. Commands to Perseverance must be scheduled three days ahead, requiring educated guesses about which solar storms will trigger events.

Between 2023 and 2024, Knutsen's team attempted eight observations using the rover's SuperCam and MastCam. Early failures were explained by slow CME velocities. "The faster the CME, the more likely it is to accelerate particles towards Mars that create aurorae," Knutsen explained. Adjusting criteria led to two successful detections, though three later trials yielded no results despite meeting expectations.

Knutsen noted that randomness plays a role, comparing the challenge to Earth's aurora forecasting. "Predicting the aurora on Earth down to minute precision isn't an exact science either," she said.

Aurorae on Mars have previously been observed in ultraviolet from orbit by ESA's Mars Express and NASA's MAVEN missions. Visible-light detections from the surface now add a crucial dataset for refining predictions and probing how aurora form without a magnetic field.

"There is still much we don't understand about how aurora occur on Mars," Knutsen added. "Comparing the timing of solar wind disturbances, the arrival of solar energetic particles and the intensity and timing of aurora will advance our knowledge in this area."