News & Opinion | July 29, 2018 5:00 am

Earth is Now 12 Miles Closer to The Edge of Space

A new study shows we need to switch our thinking about where Earth's atmosphere ends and space begins.

milky way
Milky Way (European Space Agency)

A new study published this week is making us Earthlings question where exactly Earth’s atmosphere ends and outer space begins. Based on astrophysicist Jonathan McDowell’s calculation, the cosmic boundary where the laws of airspace give way to the laws of orbital space are actually much closer than we think — a full 12 miles closer than previous estimates.

“The argument about where the atmosphere ends and space begins predates the launch of the first Sputnik,” McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, wrote in his new paper, which will appear in the October issue of the journal Acta Astronautica. “The most widely accepted boundary is the so-called Karman Line, nowadays usually set to be 62 miles altitude.”

McDowell says that Karman line is based on decades of misinterpreted information, which did not actually take real orbital data into account. McDowell studied data describing the orbital paths of some 43,000 satellites, which he collected from the North American Aerospace Defense Command (NORAD).