All the while, the space was secretly a lot closer than we thought

A new research paper proposes that we all be a little closer to the space we assumed. If the calculations prove correct, we could, in fact, be at a distance of 12 miles. The exact altitude of this boundary – the plane where the laws that regulate airspace are replaced by those governing space – is an important piece of information in world politics, the authors note.

The recalculated boundary

where the atmosphere ends and the space begins before the launch of the first Sputnik, "writes Jonathan McDowell, astrophysicist at the Harvard-Smithsonian Center for Astrophysics, and sole author of the new document. "The most widely accepted border is the so-called Karman line, currently set at 62 miles altitude."

The boundary between the atmosphere and space is known as the Kármán Line after its discoverer, aerodynamic researcher and engineer Theodore von Kármán. In 1963, when the line was proposed, von Kármán suggested that the speed needed to lift an object in the atmosphere is the same as the speed needed to keep it in orbit around the Earth. He also believed that the horizontal movement of the object on the orbit would counteract the effects of gravity. According to McDowell, however, this is not true. The position of the line was therefore calculated on the basis of an erroneous assumption and without any real means of testing – it was a time before actual orbital readings could be performed.

For his study, McDowell was inspired by the North American Aerospace Defense Command (NORAD) detailing the orbital whereabouts of more than 43,000 satellites. Most of them were in orbit above the Karman line, so McDowell pulled their way out of the study. About fifty satellites were however used in the calculations

What differentiates these 50, is that they all performed at least complete rotations around the planet at low altitude (less than 100 km ) upon their return to the atmosphere. the end of their missions. The Soviet Elektron-4 satellite, for example, made ten complete rotations around the planet at about 83 km before burning in the atmosphere in 1997. In other words, these cases revealed that the satellites could still behave as if they were in the space below the Karman line – raising the possibility that the elevation line is overestimated.

McDowell used a mathematical model to find the altitude at which the orbits of these satellites finally began to degrade. atmosphere – he found that these events occurred between 70 to 82 kilometers (41 to 55 miles) high. However, for most satellites, the mark of 80 kilometers (50 miles) seems to be the lowest stable orbit possible. McDowell therefore proposes this altitude as the new accepted boundary between our atmosphere and space.

The suggestion might actually have some weight in the scientific community. The mark of 80 kilometers corresponds to what we know about the structure of the atmosphere. The mesopause, which extends approximately 83 to 100 kilometers high, is an area where the chemical composition of the air changes radically and where charged particles become more abundant – increasing the state of the body. gases in the space. Below the lower edge of the mesopause, the Earth's atmosphere becomes a stronger force for aerial objects, writes McDowell.

"It is remarkable that meteors (traveling much faster) usually decay within 43 to 62 miles of altitude, he adds that most space operations, such as rocket launches, should remain relatively unchanged if the new frontier is adopted, writes McDowell, this could increase some important political and territorial issues

The airspace above each country is generally considered part of that country – but the only one in the world. Outer space does not belong to anyone.If the space limit is set 100 kilometers high, for example, and that an unauthorized satellite passes 80 kilometers high, this could be rightly considered as an act of military aggression between states.As satellites tend to oscillate sometimes along their orbits, a lower limit of the atmosphere could help ease tensions.

The document "The Edge of Space: Revisiting the Karman Line" will be published in the October issue. journal Acta Astronautica .

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