In the spring of 2012 amateur astronomers spotted a huge plume rising from the Marian surface and captured it on video. They’ve been seen in the past rising to an altitude of 100km, but this one rose to more than 250 km. A reflective cloud of water-ice? An auroral emission of some kind? Or could it be due to an impact? http://www.esa.int/Our_Activities/Space_Science/Mystery_Mars_plume_baffles_scientists MYSTERY MARS PLUME BAFFLES SCIENTISTS Mystery plume on Mars 16 February 2015 Plumes seen reaching high above the surface of Mars are causing a stir among scientists studying the atmosphere on the Red Planet. On two separate occasions in March and April 2012, amateur astronomers reported definite plume-like features developing on the planet. The plumes were seen rising to altitudes of over 250 km above the same region of Mars on both occasions. By comparison, similar features seen in the past have not exceeded 100 km. “At about 250 km, the division between the atmosphere and outer space is very thin, so the reported plumes are extremely unexpected,” says Agustin Sanchez-Lavega of the Universidad del País Vasco in Spain, lead author of the paper reporting the results in the journal Nature.