Before the space age, our neighboring “sister planet” Venus was a mysterious clouded world that science-fiction writers dreamed as covered by swamps and dinosaurs. Dozens of space probes were then sent to Venus, with many of them successful. These missions completely changed our vision to that of planet with very high temperature and blanketed by clouds of acid.
Venus Before Space Age
Venus was one of 4 planets known to the ancients. It is visible in morning and in evening with naked eye from earth since it is closest to earth than any other planets. It has orbit close to sun than the orbit of earth and takes 224.70 earth days to make one complete revolution (orbit) around sun.
The diameter of Venus is 12100 Kg., which is about 95% of that of earth & its mass is 81.5% that of earth, giving it a mean density of 5.24 times that of water. Due to the similar rise of earth and Venus, Venus is also known as earth's sister.
The planet is full of cloud, which was confirmed by photographs taken by American astronomer's William H. Wright & Frank E. Ross in 1927 & 1928. The global cloud layer suggested that Venus was a wet, warm planet, with Great Ocean and endless swamps. Some astronomers suspected that the CO2 atom might trap solar radiations, building up high temps by the process known as the green house effect.
Advances in radar technology let to the first radar observations of Venus from earth in 1961; revealing that the planet had a very slow rotation, in reverse direction of rotation of earth known as retrograte motion.