mountaineers carry oxygen cylinders that allow them to breathe freely at high altitudes The closer you get to the edge of Earth's atmosphere, the less oxygen there is.
This is an example of how the atmosphere of Earth is variable, from the troposphere, near sea level, to the exosphere, in its outermost regions. According to the National Weather Service, where each layer ends and begins is determined by four factors: temperature change, chemical composition, density and the movement of the gases within it.
So, where does the Earth's atmosphere end? Where does space begin?
How much water is in the atmosphere?
According to NASA, each of the atmosphere's layers plays a role in ensuring our planet can host all manner of life, doing everything from blocking cancer-causing cosmic radiation to creating the pressure required to produce water.
The atmosphere becomes less dense as you get farther from Earth, according to a space physicist.
The weight of the atmosphere above you weakens as you move up. Matthew Igel said that rapid changes in altitude can affect the slim eustachian tubes connecting the ear to the nose and throat.
Eventually, the air becomes too thin for conventional aircraft to fly at all, with such craft not able to generate enough lift. This is the area scientists have decreed marks our atmosphere's end, and space's beginning.
It's known as the Kármán line, named after Theodore von Kármán, a Hungarian American physicist who, in 1957, became the first person to attempt to define the boundary between Earth and outer space, according to EarthSky.
The boundary between Earth and space is marked by this line, and it is important for scientists and engineers to figure out how to keep satellites and aircraft in the air.
It is typically defined as 100 kilometers above Earth. There is nothing that forbids it.
It is an imaginary but practical threshold between air travel and space travel, he said.
The size and shape of the satellite play a part in determining how much air resistance it will experience and how successful it will be in circling Earth, according to Bossert. The European Space Agency says that satellites that are in low Earth orbit are usually classified as being at an altitude of less than 1,000 km but sometimes as low as 99 miles above Earth.
How fast does the Earth move?
That doesn't mean Earth's atmosphere is not visible.
Bossert said that the atmosphere doesn't just disappear once you get into the region where satellites are. The hydrogen atoms that make up Earth's atmosphere can extend beyond the moon.
So, if someone were to reach the Kármán line, would they notice anything? Would they be aware that they were, essentially, straddling the boundary between Earth and space? Not really. "Nothing really changes," Bossert said.
Igel agreed. "The line is not physical, per se, and so one would not notice crossing it, nor does it have any thickness," he said.
Is it possible to survive for a short time at the Kármán line? If you were dropped there without a spacesuit or oxygen tank, what would you do? Would you be able to breathe at such a high altitude? Is it possible that birds could ever reach such heights?
Igel said that flight is possible all the way up to the Kármán line.
It was originally published on Live Science.
All Rights Reserved © 2024
