Kármán line

The Kármán Line

The Kármán line is a special height above Earth. It is 100 kilometres, or about 62 miles, above sea level. Many people use this line to mark where the sky ends and space begins.

This line is named after a clever scientist called Theodore von Kármán. It helps countries decide which rules apply to airplanes and which ones apply to spacecraft. Even though this line is not a real wall, it is very useful.

The Kármán line is high enough that regular airplanes cannot reach it. But it is low enough that some satellites might still come back down to Earth. This line helps our world know when something is flying in the sky or traveling in space.

Different groups might pick a slightly different height, but most agree it is close to where the Fédération aéronautique internationale (FAI) sets it. The FAI uses the Kármán line to show where aeronautics ends and astronautics begins. Things happening within 100 kilometres of Earth are aeronautics. Anything above this line is astronautics.