Kármán line

Conventional definition of the edge of space

The Kármán line (or von Kármán line) is a conventional definition of the edge of space; it is widely but not universally accepted. The international record-keeping body FAI (Fédération aéronautique internationale) defines the Kármán line at an altitude of 100 kilometres (54 nautical miles; 62 miles; 328,084 feet) above mean sea level. While named after Theodore von Kármán, who calculated a theoretical limit of altitude for aeroplane flight at 83.8 km (52.1 mi) above Earth, the later-established Kármán line is more general and has no distinct physical significance, in that there is a rather gradual difference between the characteristics of the atmosphere at the line, and experts disagree on defining a distinct boundary where the atmosphere ends and space begins.

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