• NASA's Perseverance rover observed a faint green aurora on Mars on March 18, 2024.
• This is the first time auroras were seen in visible light on the Martian surface.
• The phenomenon was caused by solar energetic particles interacting with the Martian atmosphere.
• Previous auroras on Mars were recorded only in ultraviolet wavelengths.
• The findings were published in the journal Science Advances.

For the first time, NASA's Perseverance rover has captured the stunning sight of a green aurora on Mars, a scientific milestone that could transform our understanding of the planet's atmosphere. The observation occurred on March 18, 2024, when energetic particles from the sun interacted with the Martian atmosphere, resulting in a faint glow that illuminated the night sky over Jezero Crater. This event marks a significant advancement, as auroras on Mars had previously only been detected in ultraviolet light, according to Indiatimes, Reuters, and Channel News Asia.

The aurora on Mars was facilitated by a solar flare and a coronal mass ejection that occurred just days prior to the observation, which sent a wave of charged particles toward the planet. Researchers had prepared the Perseverance rover's instruments in advance to detect this expected phenomenon. Utilizing its SuperCam spectrometer and Mastcam-Z camera, scientists were able to pinpoint the wavelength of the glow and capture images of the overall illumination across the Martian sky. This innovative use of technology allowed for direct observations of the green glow from the Martian surface, marking a first for planetary science, according to Reuters and Channel News Asia.

The auroras on Mars form similarly to those on Earth, where charged particles collide with atmospheric atoms. However, unlike Earth, which has a global magnetic field directing these particles toward the polar regions, Mars lacks such a field, resulting in a planet-wide aurora effect. "Mars has no global magnetic field so the charged particles bombarded all of Mars at the same time," stated Elise Wright Knutsen, the lead researcher from the University of Oslo. She emphasized the significance of this observation, noting the differences in appearance when compared to the structured auroras seen on Earth, according to Indiatimes, Reuters, and Channel News Asia.

While the observed aurora was faint and likely too dim for human eyes to detect, like many earthly auroras, its brightness may increase during more intense solar storms. Knutsen expressed excitement about the prospect of future astronauts potentially witnessing a more vibrant display on Mars. "During a more intense solar storm, producing a brighter aurora, I think a sky which glows green from horizon to horizon will be eerily beautiful," she said. This discovery opens a new chapter in understanding not only Mars's atmospheric science but also the complexities of space weather interactions, according to Reuters and Channel News Asia.