Obviously, we know more about the atmosphere of our home planet than any other in the Solar System. Researching not only from our own surface, but in the atmosphere itself and above, using satellites pointed back toward the planet, we are able to assess the properties of the different layers and witness in real-time any dynamics such as storms or pressure changes.
Earth's different gases are essential to keeping life going on the planet. They supply the necessary support for life's respiratory systems, protect us from ultraviolet solar radiation and helps regulate the temperature to ideal levels for life. Most notably, the atmosphere is responsible for the greenhouse effect. This is the process by which the heat from the Sun is captured by the atmosphere, keeping the planet sustainably warm.
Like many of the other planets in the Solar System, the Earth's atmosphere is divided into different sections:
The first section is known as the troposphere, up to roughly 12.4 miles (20 km) from the surface. The troposphere garners its heat from the surface, meaning its warmer the closer one is positioned to the Earth's crust and cooler as one rises. This portion holds 80% of the atmosphere's mass.
Extending past the troposphere to a height of 32 miles (51 km) is the stratosphere. At its beginning, the temperature ranges around -76°F (-60°C). However, ultraviolet radiation is plentiful in this section, raising the temperature to near freezing at its peak.
The mesosphere is the next section of Earth's atmosphere, extending to roughly 53 miles (85 km). In this area, temperatures range from -120°F to -150°F (-85°C to -100°C). It is common for ice clouds to form from the water vapor and it can also exhibit lightning. This section is also responsible for the majority of protection of the Earth's surface from meteors, burning most of them up as they enter the atmosphere.
Finally reaching the levels of low Earth orbit is the thermosphere. This is a section with low density molecules and extremely high temperatures. It reaches temperatures of 2,700 F (1500 C) and heights of 220–500 miles (350–800 km). Much of the initial radiation from the Sun is absorbed here. The thermosphere accounts for the majority of the planet's atmosphere and also is the location of standard spacecraft flight and the home of the International Space Station.
The final section of Earth's atmosphere is the exosphere. Mainly composed of helium and hydrogen, this part features molecules and elements that come and go with the solar wind.
Earth's atmosphere is fairly volatile compared to others in the Solar System. It features water rainfall, high velocity winds and phenomena such as hurricanes, tornadoes and blizzards. Research into other atmospheres helps us understand the causes behind such events and how they may increase or decrease in severity.
- Nitrogen 78.084%
- Oxygen 20.946%
- Argon 0.9340%
- Water Vapor 0.4%
- Carbon Dioxide 390 ppm
- Neon 18.18 ppm
- Helium 5.24 ppm
- Methane 1.79 ppm
- Krypton 1.14 ppm
- Traces of Hydrogen, Nitrous Oxide, Carbon Monoxide, Xenon, Ozone, Nitrogen Dioxide, Iodine, and Ammonia