The outgoing peak of solar activity has given humanity many magnificent auroras on Mars. One of them, which lit up the Red Planet on March 15, 2024, went down in history as the first to be captured from its surface in the visible range.
The photos and data from the Perseverance spectrometer have finally been processed and analysed. The results were published in the journal Science Advances.
“This exciting discovery opens up new opportunities for polar aurora research and confirms that future astronauts on the surface of Mars will be able to see them,” lead author Elise Knudsen of the University of Oslo said.
On earth, polar auroras are caused by the interaction of solar wind particles with the planet’s magnetic field and they are usually confined to polar regions. They are predominantly green in colour, which is the wavelength of oxygen at 557.7 nanometres.
Mars also has polar auroras, but due to the absence of a global magnetic field, they are different from ours and occur at all latitudes. One type of Martian aurora is caused by solar energetic particles (SEPs), which were discovered by the MAVEN (Mars Atmosphere and Volatile EvolutioN) mission in 2014.
Although MAVEN observed SEP auroras in ultraviolet light from orbit, this phenomenon has never been recorded in visible light from the surface. Since SEP auroras usually occur during solar storms, scientists decided to take advantage of our sun’s peak activity.
Using modelling, they determined the optimal angle for the SuperCam spectrometer and the Mastcam-Z camera on the Perseverance rover to successfully observe SEP glows in visible light. All that remained was to wait for the right moment and correctly predict the coronal mass ejection (CME).
