Decades of discussion and progress in instruments to analyze the cosmos and scientists cannot agree on a topic that, although it may seem, is not at all simple: what is the border between Earth and space. Where is that imaginary line in which we can officially say that on one side it is planet and the other is already dark matter.
The Earth and space are two bodies that touch, but be careful, they do not mix: one is one and the other is another. And although the border between the two is certainly invisible, that limit should exist, that kilometer or zero point to start counting on both one side and the other.
The debate among scientists is divided into two options: one is the so-called line of Kármán and the other is the Exobase.
Borders between Earth and space
The Kármán line is located at 100 kilometers altitude, as the division point. This sector, named this way, since it was proposed by the scientist Theodore von Kármán in the 1950s, is based on the density of the air being too low for a commercial airplane to fly under conventional conditions.
Those who do not agree with this theory say that it is impossible to mark an exact point between Earth and space, since the atmosphere is diluted as one ascends towards the planet's orbit.
So, those who argue with this concept say that the border between world and space is the Exobase, the outermost layer of the Earth's atmosphere, which is between 500 and 1000 kilometers in altitude. In this region, molecules from the Earth's atmosphere escape into space due to low gravity and therefore consider this to be where the true frontier governs.