01
Venus's thick CO₂ blanket
Venus's atmosphere is about 96% carbon dioxide and 90× thicker than Earth's, trapping heat in a runaway greenhouse effect.
Solar system · Question
Why is Venus hotter than Mercury?
Mercury is the closest planet to the Sun. Venus is the second closest — and yet Venus is the hottest planet in the solar system, hotter than Mercury by over 250°C. Distance from the Sun isn't the whole story.
Visual model
Average temperature, all eight planets.
Bar height shows how far each planet's average temperature is from 0°C — red bars are above freezing, blue bars are below. Hover or tap a bar for the exact number.
What's simplified
Distance isn't the deciding factor. Atmosphere is.
02
Mercury has almost none
Mercury has essentially no atmosphere to trap heat, so its dayside bakes while its nightside can drop to -180°C — the "average" hides an enormous swing.
03
These are averages
A single number can't show day/night or pole/equator swings, which are extreme on airless worlds like Mercury and the Moon.
Misconception check
Quick check.
Quick check
Go deeper
Keep exploring.
Next in this series →
Orbital periods ↗
Calculate your age on Mars or Jupiter.
Gravity
Weight on other planets
Another way a planet's numbers surprise you.
Home
Solar system model
Back to the interactive 3D solar system.