Venus is different from the other planets in the solar system in many ways, but its atmosphere is one of the most striking differences. Venus has the densest atmosphere of all the planets in the solar system, exerting over 90 times the pressure of Earth's at surface level.
Although the gas giants Jupiter, Saturn, Uranus and Neptune have thick and dense atmospheres, it is unknown where their surfaces are, so pressure cannot be calculated. The atmosphere of Venus consists mostly of sulfuric acid and carbon dioxide. Carbon dioxide creates a runaway greenhouse effect, making Venus the hottest planet in the solar system, despite Mercury being closer to the sun. Venus has a daytime temperature of 867 degrees Fahrenheit. The atmosphere is so thick and dense that scientists only recently have been able to map the surface of the planet, as of 2015. The surface consists of relatively young mountains and lava flows, as well as rift valleys.
Venus is also one of the only two planets in the solar system to possess retrograde rotation, or rotating from east to west rather than west to east. In addition, the rotation takes longer than the orbit, making a day on Venus longer than its year.