# Detection of visible-wavelength aurora on Mars

## TL;DR

Scientists detected green auroras on Mars using the Perseverance rover, marking the first visible aurora observed on a planet other than Earth.

## Contribution

First detection of visible-wavelength aurora on Mars from its surface using rover instruments.

## Key findings

- Green aurora on Mars was detected at 557.7 nanometers using SuperCam and Mastcam-Z.
- Aurora occurred 3 days after a coronal mass ejection, likely caused by accelerated particles from the shock front.
- This suggests auroral forecasting is possible on Mars and auroras could be visible to future astronauts.

## Abstract

Mars hosts various auroral processes despite the planet’s tenuous atmosphere and lack of a global magnetic field. To date, all aurora observations have been at ultraviolet wavelengths from orbit. We describe the discovery of green visible-wavelength aurora, originating from the atomic oxygen line at 557.7 nanometers, detected with the SuperCam and Mastcam-Z instruments on the Mars 2020 Perseverance rover. Near–real-time simulations of a Mars-directed coronal mass ejection (CME) provided sufficient lead-time to schedule an observation with the rover. The emission was observed 3 days after the CME eruption, suggesting that the aurora was induced by particles accelerated by the moving shock front. To our knowledge, detection of aurora from a planetary surface other than Earth has never been reported, nor has visible aurora been observed at Mars. This detection demonstrates that auroral forecasting at Mars is possible, and that during events with higher particle precipitation, or under less dusty atmospheric conditions, aurorae will be visible to future astronauts.

Green aurora lit up the martian sky following a solar storm eruption, captured by instruments on the Mars 2020 Perseverance rover.