Is Mars hot?
Short answer: No, on average it's colder than Earth.
Long answer: Mars has two problems keeping warm:
- It's farther from the Sun than Earth so it gets less heat to start with.
- Its atmosphere is very thin—1% of Earth's atmospheric pressure—so it can't easily hold onto the heat it gets from the Sun.
The average temperature on Mars is -60°C (-80°F) which is too cold for humans to survive. However it does get much warmer in summer, especially in certain low-lying areas where the air pressure is greater. Near the equator it can reach 20°C (68°F).
Winter, on the other hand, is very cold indeed. Around the poles it can get as low as -125°C (-195°F).
Why do people think Mars is hot? Probably because it looks red and we associate the colour red with heat. Venus looks like it should be colder than Mars but of course it's actually much hotter (the hottest in the Solar System). Like many things in astronomy, all is not as it first appears.
Above: Frost on Mars.
Photo taken by the Viking robotic lander in 1979.
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