What is the hottest planet?
Venus is the hottest planet, at about 465°C (870°F) on the surface, hot enough to melt lead. It is even hotter than Mercury, which is closer to the Sun.
Venus is wrapped in a thick atmosphere that is about 96 percent carbon dioxide. The pressure at the surface is about 90 times that on Earth. Sunlight reaches the ground and warms it, but the dense atmosphere traps the heat. This runaway greenhouse effect keeps the whole planet almost equally hot, day and night.
Mercury is closer to the Sun, but it has almost no atmosphere to hold heat. Its daytime side reaches about 430°C, while its night side drops to about −180°C. Venus stays hotter than Mercury's hottest spot all the time.
A strange world
Venus is covered by clouds of sulfuric acid that reflect much of the sunlight, making it the brightest planet in our night sky. It also spins backward compared with most planets, and so slowly that one day on Venus is longer than its year. Soviet Venera landers sent back photos of the surface in the 1970s and 1980s, but they survived only a couple of hours.
Did You Know?
From Earth, Venus is often called the Morning Star or the Evening Star, because it shines brightly just before sunrise or just after sunset. It is the hottest planet, but it is also the planet that comes closest to Earth.