These searing temperatures are caused by Venus’ thick atmosphere, which is composed mainly of carbon dioxide. As we know from its role in climate change on Earth, carbon dioxide is a greenhouse gas. When the Sun’s light heats Venus, the heat can’t efficiently radiate back into space because it’s trapped by the carbon dioxide in the atmosphere. This heats the planet up dramatically.
The coldest places in the Solar System
The Oort Cloud
As logic would suggest, the farther you go from the Sun, the colder things get. This is why the Oort Cloud, the group of icy objects extending from about 2,000 to 100,000 astronomical units (the average Sun-Earth distance, also know as AUs) from the Sun, likely hosts some of the coldest environments in our Solar System.
While we haven’t studied any of these objects up-close in their home environment, the inner Solar System does sometimes get visitors from the Oort Cloud: comets.