On Earth, our temperature scales are calibrated based on some universal (on Earth) values. For example, 212°F and 100°C are defined as the temperature water boils at sea level.

How are these calibration values decided on other planets? Many planets don't have a 'sea level' and if they did, atmospheric pressure would still be different. How would thermometers be calibrated on other planets?

  • $\begingroup$ As you can read here en.wikipedia.org/wiki/International_Temperature_Scale_of_1990 the boiling point of water is not used to define 100 °C anymore. If the calibration points are defined with care, calibration is possible on other planets too. As far as the calibration points are independent of the planets gravity. $\endgroup$
    – Uwe
    Commented Jan 10, 2017 at 12:28

1 Answer 1


I think you have it backwards - it doesn't matter where in the universe you are, absolute zero is still the same (-273.15°C) and the temperature increase marked by 1 Kelvin or 1 Centigrade is the same, so you could find a calibration point on any planet that came to the same temperature and list that as the way to measure 100°C etc.

Realistically though, you wouldn't need to do this, and you just wouldn't use a thermometer that had any gaseous or liquid connection to the outside environment. It is much easier to not have to worry about it.

Calibrate your thermometers on earth before you go traipsing round other planets.

  • 1
    $\begingroup$ But I dropped my thermometer on Ganymede... $\endgroup$
    – Chad
    Commented Sep 3, 2013 at 14:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.