Here's why:
* Venus's Atmosphere: Venus has a thick, dense atmosphere composed primarily of carbon dioxide. This atmosphere traps heat from the Sun through a process called the greenhouse effect, making the surface of Venus incredibly hot.
* Mercury's Proximity to the Sun: While Mercury is the closest planet to the Sun, it has a very thin atmosphere. This lack of atmosphere means that there is little to no insulation against the Sun's heat, and the heat that does reach Mercury is quickly radiated back into space.
So, while Mercury receives a lot of sunlight, it doesn't retain the heat like Venus does, making Venus significantly hotter.
