 The existence of an atmosphere on Venus was concluded by Mikhail Lomonosov on the basis of his observation of the transit of Venus of 1761 from the Imperial Academy of Sciences of St. Petersburg . He used a two @-@ lens <unk> <unk> and a weak solar filter ( smoked glass ) and reported seeing a bump or <unk> of light ( " Lomonosov 's arc " ) off the solar disc as Venus began to exit the Sun . Lomonosov attributed that effect to refraction of solar rays through an atmosphere ; he also reported the appearance of a <unk> around the part of Venus that had just entered the Sun 's disk during the initial phase of transit . In 2012 , <unk> and <unk> reported , based on knowing what Venus 's atmosphere would look like because of <unk> and Schneider 's observations of the 2004 transit of Venus , that what Lomonosov reported was not Venus 's atmosphere . To make a decisive test , a group of researchers carried out experimental reconstruction of Lomonosov 's discovery of <unk> atmosphere with antique <unk> during the transit of Venus on 5 – 6 June 2012 . They observed the " Lomonosov 's arc " and other <unk> effects due to Venus 's atmosphere and concluded that Lomonosov 's telescope was fully adequate to the task of detecting the arc of light around Venus off the Sun 's disc during <unk> or <unk> if proper experimental techniques as described by Lomonosov in his 1761 paper are employed . 
