: Earth's toxic twin. It is blanketed by a thick, heavy atmosphere of carbon dioxide that traps heat like a runaway greenhouse. This makes it the hottest planet in the solar system at a steady 900°F (475°C)—hot enough to melt lead.
These are the four planets closest to the Sun. They are made of rock and metal and have solid surfaces you could actually walk on. planet
Moving past the asteroid belt, we find massive worlds made mostly of hydrogen and helium gas with no true solid surfaces. About the Planets - NASA Science : Earth's toxic twin
: The ultimate land of extremes. Because it has virtually no atmosphere to trap heat, daytime temperatures soar to a blistering 840°F (450°C), while nights plummet to a frozen -275°F (-170°C). These are the four planets closest to the Sun