Atmosphere of Venus
In 1761, Russian polymath Mikhail Lomonosov observed an arc of light surrounding the part of Venus off the Sun's disc at the beginning of the egress phase of the transit and concluded that Venus has an atmosphere. In 1940, Rupert Wildt calculated that the amount of CO in the Venusian atmosphere would raise surface temperature above the boiling point for water. This was confirmed when Mariner 2 made radiometer measurements of the temperature in 1962. In 1967, Venera 4 confirmed that the atmosphere consisted primarily of carbon dioxide.
Venus Atmospheric Maneuverable Platform
Since some models suggest Venus once had a habitable climate with liquid water on its surface for as long as 2 billion years, it is speculated by some scientists that these absorption features could be caused by large masses of microorganisms suspended in the lower cloud layer, and hypothetically thrive on iron- and sulfur-centered metabolism. On Earth, some extremophile bacteria can thrive in very acidic conditions, can feed on carbon dioxide, and excrete sulfuric acid.