The largest and hottest planet in the solar system is Venus. It has a diameter of about 12,104 kilometers, making it similar in size to Earth, but its atmosphere is incredibly dense and composed mainly of carbon dioxide. Venus's thick cloud cover traps heat through the greenhouse effect, resulting in surface temperatures that can reach around 465 degrees Celsius (869 degrees Fahrenheit). This extreme heat surpasses that of Mercury, the closest planet to the sun, due to Venus's atmospheric conditions. Despite its scorching temperature, Venus showcases interesting geological features, including mountains and volcanic activities.