N°3 - How does the Earth discharge its energy towards space?

The Earth is surrounded by space, known to be almost empty and very cold. Cruising on a plane at an altitude of 10,000 [m], the pilot announces temperatures in the -40 [°C] (-40°F) range. The temperature in space has been calculated to be -270 [°C] (- 454°F) (3 degrees Kelvin).

Surface temperature in land and ocean is on average +15 [°C] (59°F), but when observed from space the temperature of the Earth is -19 [°C] (- 2.2°F). The latter temperature allows the planet to discharge as radiation the heat it receives from the sun and from the center of the Earth. Across the planet, this temperature is approximately equal to the temperature of the ...