Venus has the densest atmosphere and is mainly composed of carbon dioxide. According to the NASA, at its surface, Venus has an atmospheric pressure that is 92 times higher than that of Earth.
The second planet from the sun, Venus has a surface temperature of 840 degrees Fahrenheit, making its surface hotter than an oven. Reflective, opaque clouds of sulfuric acid cover Venus, which makes its surface invisible in normal light, according to Wikipedia. Venus is closest to Earth with which it shares some similarities. The two are similarly sized with similar gravity and are composed of similar material, which is mainly silicate rocks and metals. Venus orbits the sun once every 224.7 Earth days.