High Quality Content by WIKIPEDIA articles! The Karman line lies at an altitude of 100 km above the Earth''s sea level, and is commonly used to define the boundary between the Earth''s atmosphere and outer space. This definition is accepted by the Federation Aeronautique Internationale (FAI), which is an international standard setting and record-keeping body for aeronautics and astronautics. The line was named after Theodore von Karman, a Hungarian-American engineer and physicist who was active primarily in the fields of aeronautics and astronautics. He first calculated that around this altitude the Earth''s atmosphere becomes too thin for aeronautical purposes. Also, there is an abrupt increase in atmospheric temperature and interaction with solar radiation