Scientists Locate the 'Edge of Space'
By Andrea Thompson
Condensed by Native Village
Scientists have finally
pinpointed the so-called edge of space -- the
boundary between Earth's atmosphere and
outer space. Scientific data from a new instrument
called the Supra-Thermal Ion Imager
confirms that space begins 73
miles above Earth's surface.
Developed by scientists from the University of Calgary, the STII was carried 124 miles into space by the JOULE-II rocket in 2007. As it moved through the "edge of space," it tracked the gentle winds of Earth's atmosphere and the violent flows of charged space particles that can travel over 600 mph. The data allowed scientists to calculate energy flows that may help us understand how space and our environment interact. "That could mean a greater understanding of the link between sunspots and the warming and cooling of the Earth's climate as well as how space weather impacts satellites, communications, navigation, and power systems," said one scientist.
Despite the Supra-Thermal Ion Imager's findings, however, the "edge of space" definition is arbitrary. Other definitions include:
Astronauts say they've been in space after passing the 50-mile mark;
The space industry says the edge of space is around 62 miles. This 62-mile boundary is accepted by the Federation Aeronautique Internationale (FAI), which sets aeronautical standards;
NASA's mission control uses 76 miles as their re-entry altitude;
Others say the edge of space is 13,000,000 miles away because that's where Earth's gravity is no longer dominant.