Venus is the second planet from the Sun and is often described as Earth's "sister planet" due to its similar size and mass, although significant differences exist in surface conditions. The planet is covered by a dense atmosphere composed primarily of carbon dioxide, which traps heat and creates a runaway greenhouse effect, resulting in surface temperatures hot enough to melt lead. Its extremely thick atmosphere and high surface pressure give it a unique geological and climatic profile. Furthermore, Venus exhibits a retrograde rotation relative to most other planets in the solar system, and its cloud tops are characterized by pervasive sulfuric acid compounds.