Scientists predict Mars’ green aurora and its glow with new method

Scientists Predict Mars’ Green Aurora with New Method (Image: Canva)

For centuries, aurorae have fascinated observers on Earth. Now, scientists have captured green aurorae glowing above Mars. NASA’s Perseverance rover first observed this phenomenon in 2024. New research now allows prediction of such events.

How Do Auroras Appear in Mars’ Sky?

Aurorae happen when energetic particles collide with atmospheric molecules. These particles are sent by solar coronal mass ejections. On Mars, they strike oxygen atoms high in the atmosphere. This interaction creates a visible green glow.

Dr Elise Wright Knutsen of the University of Oslo led the study. She shared findings at the Europlanet Science Congress in Helsinki. The new research shows Perseverance captured a second aurora snapshot.

Unlike Earth, Mars lacks a magnetic field. This means aurorae can appear anywhere on the planet’s night side. Scientists call this a diffuse aurora. The aurora could be bright enough for astronauts to see.

Artist’s illustration showing how the aurora could appear above Perseverance rover. (Image: Alex McDougall-Page, University of Strathclyde/AstrollCareers)

Why Is Predicting Mars Aurora Important?

Solar storms are dangerous for future Mars astronauts. Predicting aurora helps warn about incoming radiation bursts. Researchers must upload observation plans to Perseverance three days prior. Timing depends on when a solar storm targets Mars.

Knutsen’s team made eight observation attempts between 2023 and 2024. The first three attempts found no aurora visible. Analysis showed early CMEs lacked necessary speed or strength.

Perseverance Mastcam-Z captured aurora and non-aurora nights, showing green oxygen glow, sky colour contrasts, and spectra matching theoretical aurora intensity models. (Image: Elise Wright Knutsen et al.)

“The faster the CME, the likelier it is to cause aurora,” Knutsen explained. The team then targeted faster, more intense solar events. This strategy led to the first two successful detections.

However, the last three attempts again failed, despite matching criteria. Knutsen said, “There is a degree of randomness in aurora predictions.” She compared this to aurora forecasts on Earth.

What Do These Discoveries Mean for Future Research?

Previously, ESA’s Mars Express and NASA’s MAVEN observed aurora in ultraviolet light. Now, visible-light detections are expanding the data available. The growing dataset aims to improve aurora prediction accuracy.

Further observations will help scientists understand aurora triggers better. Knutsen said much remains unknown about Mars’ auroral processes. Without a global magnetic field, predicting timing remains difficult.

She concluded, “Comparing solar wind, energetic particles, and aurora timing advances knowledge.” Scientists hope these insights will protect future Mars explorers.