Why is Venus hotter than Mercury, though it’s farther from the Sun?
The short answer first, then the real reason — and a version for younger kids. Guess before you scroll to make it stick.
✅ Venus’s thick blanket of air traps the heat
But why?
Merther has no air, so its heat escapes each night; its average is modest despite scorching noontimes. Venus has 90 atmospheres of CO₂ with sulfuric-acid clouds — infrared radiation from the surface is absorbed and re-radiated back down, multiplying the temperature far beyond what distance alone predicts. It’s the solar system’s warning label on greenhouse gases.
🧒 For younger kids: Venus wears a giant blanket of clouds! Sun gets in, heat can’t escape — hottest planet wins!
🤯 Wow fact: Venus is hot enough to melt lead — and its surface pressure would crush a submarine like a can.
Good guesses kids make
“Because Venus is a young star” — Venus is a planet, not a star — it shines only by reflected sunlight.
“Because Venus has volcanoes everywhere” — Venus IS volcanic, but its heat is trapped sunlight — lava adds little next to the greenhouse blanket.
“It’s actually not hotter — that’s a myth” — It really is: Venus averages about 465°C — hot enough to melt lead — while Mercury’s average is far lower.
More space why questions
- Why is the sky blue?
- Why does the moon change shape?
- Why do stars twinkle?
- Why do astronauts float inside the space station?
- Why is Mars red?