At the top altitude of the Earth the gas concentration is very low.

In that area how do we measure the temperature?

I think very small number of the molecules collide with the sensor of the instrument per min.

Edited January 3, 201115 yr by alpha2cen

You measure the intensity of emitted radiation at a few different wavelengths and use the blackbody equation to get the temperature

You measure the intensity of emitted radiation at a few different wavelengths and use the blackbody equation to get the temperature

Highly moving neutral atom sensing is not easy.

We can not measure electron and ion temperature that way.

Are there another method to measure them?

Edited January 4, 201115 yr by alpha2cen

Hi, great information i am looking forward to get different kind of question about science and gonna ask simple thing from you with respect that is kelvin comes first or Celsius..

Celsius scale was made first. It was made by using water freezing point and boiling point.