Worlds in Collision
Tim Callahan, religion editor of "Skeptic", presses the case further in claiming that the composition of the atmosphere of Venus is a complete disproof of "Worlds in Collision". "...Velikovsky's hypothesis stands or falls on Venus having a reducing atmosphere made up mainly of hydrocarbons. In fact, the atmosphere of Venus is made up mainly of carbon dioxide—carbon in its "oxidized" form—along with clouds of sulfuric acid. Therefore, it couldn't have carried such an atmosphere with it out of Jupiter and it couldn't be the source of hydrocarbons to react with oxygen in our atmosphere to produce carbohydrates. Velikovsky's hypothesis is falsified by the carbon dioxide atmosphere of Venus."
Atmosphere of Venus
The mesosphere of Venus can be divided into two layers: the lower one between 62–73 km and the upper one between 73–95 km. In the first layer the temperature is nearly constant at 230 K (−43 °C). This layer coincides with the upper cloud deck. In the second layer temperature starts to decrease again reaching about 165 K (−108 °C) at the altitude of 95 km, where mesopause begins. It is the coldest part of the Venusian dayside atmosphere. In the dayside mesopause, which serves as a boundary between the mesophere and thermosphere and is located between 95–120 km, temperature increases to a constant—about 300–400 K (27–127 °C)—value prevalent in the thermosphere. In contrast, the nightside Venusian thermosphere is the coldest place on Venus with temperature as low as 100 K (−173 °C). It is even called a cryosphere.