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."
Venera 4
In 1967 it was the first successful probe to perform in-place analysis of the environment of another planet. It may also have been the first probe to land on another planet, with the fate of its predecessor Venera 3 being unclear. Venera 4 provided the first chemical analysis of the Venusian atmosphere, showing it to be primarily carbon dioxide with a few percent of nitrogen and below one percent of oxygen and water vapors. The station detected a weak magnetic field and no radiation field. The outer atmospheric layer contained very little hydrogen and no atomic oxygen. The probe sent the first direct measurements proving that Venus was extremely hot, that its atmosphere was far denser than expected, and that it had lost most of its water long ago.