In 2018, a camera on board the Mars Express mission caught sight of a strangely long and wispy cloud, billowing across the surface of the red planet.
From a distance, the 1,500-kilometer (930-mile) trail of fog almost resembled a plume of smoke, and it seemed to be emerging from the top of a long-dead volcano.
Looking back at archived images, researchers soon realized this had been happening for a while. Every few years in spring or summer, this curious cloud would return, before disappearing once again. The fleeting plume was caught on camera in 2009, 2012, 2015, 2018, and again in 2020… More about this article in the link below…
