An article published in the journal “Nature Astronomy” describes the discovery of proton aurorae on the planet Mars. Scientists from NASA’s MAVEN mission were studying the red planet’s atmosphere using the space probe’s IUVS instrument and noticed a strange glow in its upper layers. The investigation led to the discovery of this rare type of aurora caused by energetic protons carried by the solar wind, a phenomenon that can occur on a large scale on Mars and perhaps also on Venus and Titan while it’s limited on Earth.