Venus Is Hotter Than Mercury: The Heat Blanket That Traps the Heat

Venus ends up hotter than Mercury not because it’s closer to the Sun, but because its thick CO2 atmosphere and dense clouds trap heat so effectively that infrared energy is repeatedly absorbed and re-emitted, creating a strong greenhouse effect. Mercury, by contrast, has almost no atmosphere, so it heats during the day but cools dramatically at night. Even though Venus reflects a large portion of sunlight, the atmosphere’s heat-trapping blanket means the planet’s surface stays extremely hot, illustrating that distance from the Sun is only part of a planet’s climate story.