Last Reviewed and Updated on June 14, 2022
Why is Venus hotter than Mercury if Mercury is closer to the sun? Wouldn’t it make sense that the closer to the Sun you are the hotter it should be? Well yes, and no. And the answer depends on a few factors.
How hot is Venus and hot is Mercury?
The mean temperatures of these two planets are as follows.
Mercury – 333°F / 167°C (also check these cool Mercury facts)
Venus – 867°F / 464°C
Source: NASA
You can see Venus is hotter and the difference in mean temperatures is significant.
All other planets tend to be colder the further they are from the Sun.
Why is Venus Hotter Than Mercury?
Now it’s time to look at the why. But first, thing first. If Venus and Mercury would be the same, with the same conditions, then Mercury would be hotter than Venus as distance most certainly plays a role in the temperatures of the planets.
But distance isn’t the only factor and here lies your answer. The main culprit for the difference is the atmosphere of the planets. Venus has a dense atmosphere while the atmosphere on Mercury is very thin.
The atmosphere of Venus is packed with carbon dioxide, while Mercury has very little carbon dioxide. If you are eco-conscious you might be aware of carbon dioxide and that this gas is what we call a greenhouse gas.
Greenhouse gases are gasses that trap heat in the atmosphere of a planet and consequentially, warm the planet. The greater the concentration of these gasses the stronger the greenhouse effect.
We perceive carbon dioxide as a problematic greenhouse gas on Earth and it’s making up less than 0.5% of our atmosphere.
The atmosphere of Venus has more than 96% carbon dioxide. That is a lot of greenhouse gas.
It’s the atmosphere of Venus that traps the heat and ultimately makes this planet hotter than Mercury.