The hottest planet in our solar system is Venus. Despite being second from the Sun, Venus has a thick atmosphere composed mainly of carbon dioxide, with clouds of sulfuric acid, creating an extreme greenhouse effect. This results in surface temperatures averaging around 465 degrees Celsius (869 degrees Fahrenheit), making it even hotter than Mercury, the closest planet to the Sun. The unbearable heat, combined with high atmospheric pressure, makes Venus an inhospitable place for any known form of life, and its harsh conditions have been the subject of scientific study for many years.