The top of the atmosphere begins about 56 miles above the Earth’s surface.
The upper atmosphere is generally considered to be the region of the thermosphere, which is the thin outer layer of Earth’s atmosphere that begins at about 56 miles (90 kilometers) and extends to about 375 miles (604 kilometers). Spacecraft like the International Space Station (ISS) or the US Space Shuttle typically orbit in the upper atmosphere at a distance of about 140 miles (225 kilometers). In contrast, commercial airliners travel much lower in the stratosphere, which extends to a maximum height of 31 miles (50 kilometers), where the Earth’s ozone layer exists.
Ozone protects the Earth from deadly ultraviolet radiation.
Although the concentration of air from the Earth’s upper atmosphere in the thermosphere region is very small compared to what people experience on the Earth’s surface, this atmosphere is also very hot due to the radiation it receives from the sun. . Estimates of atmospheric gases in the upper thermosphere put their temperature at up to 3,600° Fahrenheit (2,000° Celsius). However, due to the rarity of atmospheric gases at this level, their heat is not transmitted to objects passing through the region.
The Mir space station orbited Earth in the upper atmosphere.
A fifth layer of the upper atmosphere that merges with the vacuum of space and is often not considered part of the actual atmosphere is the exosphere. The air density of the exosphere is extremely low, and the region extends from about 375 miles (604 kilometers) to 6,200 miles (9,978 kilometers). The exosphere merges with regions of the Van Allan radiation belt above it, an area of strongly charged magnetic particles generated and held in place by Earth’s magnetic field. The exosphere is so thin that there is only about one atom of air or hydrogen per cubic centimeter of space in the upper regions, and more than 50% of these molecules eventually escape into space. The region is used for many low-orbiting satellites that are not affected by rarefied gases.
The upper atmosphere is home to the northern lights and the aurora australis.
One of the unique aspects of the upper atmosphere is that it hosts auroras such as the Northern Lights and the Northern Lights, or the Northern Lights and Northern Lights, which are most clearly visible between 10° and 20° latitude from the North Poles. or south. . . The lights are generated by magnetic effects that the Earth generates when it interacts with the solar wind and atmospheric gases at this level. The colors displayed by lights in the upper atmosphere depend on the type of air molecules affected, with green to reddish-brown colors produced by oxygen, blue by ionized nitrogen, and red by nitrogen in a lower energy state.