Venus is the second planet from the Sun and often called Earth’s twin because of its similar size, mass, and composition, yet it is one of the most hostile places in the solar system. It is the hottest planet, with surface temperatures reaching about 465°C (869°F)—hot enough to melt lead—due to a runaway greenhouse effect caused by its thick atmosphere of carbon dioxide, with clouds of sulfuric acid that trap heat. Venus rotates extremely slowly and in the opposite direction to most planets, meaning a day on Venus (one full rotation) lasts about 243 Earth days, while its year (one orbit around the Sun) is only 225 Earth days, making a day longer than its year. Its surface is covered with vast volcanic plains, mountain ranges, and thousands of large volcanoes, some of which may still be active. The crushing atmospheric pressure on Venus is about 92 times that of Earth’s, equivalent to being nearly a kilometer underwater. Venus has no moons or rings and reflects sunlight so brightly that it is the third-brightest object in our sky after the Sun and Moon, often called the morning star or evening star. Spacecraft like Venera, Magellan, and more recently Akatsuki have revealed details of its surface and atmosphere, though extreme conditions make exploration challenging. Despite its harshness, Venus offers valuable insights into climate science, planetary geology, and the future of Earth if greenhouse gases were to spiral out of control.