Venus is known as Earth's "sister planet" due to its similar size, composition, and proximity to Earth. Both planets are rocky and terrestrial, with Venus having a diameter of about 12,104 kilometers, only slightly smaller than Earth's 12,742 kilometers. However, the conditions on Venus are vastly different; it has a thick atmosphere primarily composed of carbon dioxide, resulting in extreme surface temperatures, intense pressure, and a deadly greenhouse effect. The study of Venus provides valuable insights into planetary formation and the potential for life in varying environments. Understanding Venus helps scientists draw comparisons with Earth's climate and geology.