Chapter 11, Evening and Morning Star, Chapter 12, The Ground Melts Summary and Analysis

Venus is both the evening and morning star, along with being the subject of Chapter 11. Venus was first explored in 1960 and 1961 by Mariners 1 and 2. Sagan reviews the structure of the Venusian atmosphere, thick with sulfuric acid. Galileo 1 traveled to Venus twenty years later. The Pioneer 12, Magellan and Soviet Venera 15 and 16 used radar telescopes on Venus years later.

Many conceived of Venus as a sister world, as it has similar gravitation, mass and size to earth. However, it is in fact much different and this became clear in the mid twentieth century. It was much hotter than imagines and this heat was difficult to explain. Sagan then reviews competing explanations and his role in the theoretical controversy. He covers the discoveries of the various satellites that...