Solis Lacus, meaning “Lake of the Sun” in Latin, is a dark patch lying south of the canyon system, Valles Marineris. It is surrounded by a light-coloured region known as Thaumasia. This colour contrast, along with the way Solis Lacus seems to change in size and shape occasionally, gives it the appearance of the pupil of an eye. So it is also known as Oculus (which means “eye” in Latin), and more simply, the Eye of Mars!
Though Solis Lacus was first observed and sketched by a French-Italian astronomer, Jacques Maraldi, in 1704, it was the Italian astronomer, Giovanni Schiaparelli, who gave it its present name. But what had he seen in Solis Lacus that made him call it a lake where there was none?
During the late 1800s, astronomers were limited by the ability of their telescopes – their magnification power was low, compared to that of the telescopes of today. So Schiaparelli, who could see only light- and dark-coloured patches on Mars, thought the paler areas were continents and the darker areas were seas (“mare” in Latin) or lakes “lacus”)! The American astronomer, Percival Lowell, took this belief one step further. He thought he saw his Martian channels intersect in this dark area, and concluded that Solis Lacus was the capital city of Mars. Today we know that the changing shape of Solis Lacus is due to dust storms that frequently pass over this area.
Picture Credit : Google
