How big is the earth’s Atmosphere
Remember the earth’s modern atmosphere is quite different from earth’s prebiotic atmoshpere. Earth is the only planet in the solar system to sustain life. The earth’s atmosphere plays an important role in sustaining life on earth due to oxygen in its atmosphere. The air we breathe contains oxygen utmost necessary for the survival of our life. If the earth was without this atmosphere, there would be no life of any kind on earth, just like the uninhabitable moon with a thin atmosphere and contains argon.
As our altitude (vertical height from sea level) increases, air pressure decreases. At sea level, air pressure is about 1 kilogram per square centimeter. At 3 kilometers above sea level, the air pressure is 0.7 kilogram per square centimeter. The concentration of oxygen also decreases with height that makes breathing difficult at high altitudes. About 99% of the total mass of the atmosphere is below 30 km.
The atmosphere thins out in each higher layer until the gasses dissipate in space. There is no definite boundary between the atmosphere and the outer space. The Karman line, at 100 km is often used as the imaginary border between the atmosphere and outer space.
Atmospheric layers
Troposphere: It extends from Earth’s surface up to 5 km at the poles, and about 20 km at the equator and contains 50% of Earth’s atmosphere. As height increases, temperature decreases. The temperature drops about 6.5 degrees Celsius for every kilometer above the earth’s surface.
The troposphere is denser than all the other layers, and it contains up to 75% of the mass of the atmosphere. It contains all the water vapors and moistures of the atmosphere and hence all weather activities take place here.
By volume, dry air contains, Nitrogen – 78.09 %, Oxygen – 20.95 %, Argon – 0.93 %, Carbon dioxide – 0.039 %, Water vapors on average around 1% and small amounts of other gasses.
2. Stratosphere: It is 20- 50 km above the earth’s surface. It contains Ozone gas, which absorbs all the harmful ultraviolet radiations of sunlight. The air in this layer is about thousand times thinner here than it is at sea level.
The high temperature in the stratosphere is due to an increasing amount of ozone. It is caused by the absorption of ultraviolet (UV) radiation from the Sun by the ozone layer. Jet airplanes fly in this layer.
3. Mesosphere: It is 50-85 km above the earth’s surface. The mesosphere is the coldest of the atmospheric layers with –90°C temperature. The highest clouds reach the lower part of the stratosphere. It is cold enough to freeze water vapor into ice clouds. You can see these clouds if sunlight hits them after sunset. The mesosphere is also the layer in which a lot of meteors burn up. From the Earth they are seen as shooting stars. Satellites and space shuttles orbit at the top of this level.
4. Thermosphere: It is 85 km to 600 km above the earth’s surface. The air density here is too low. The small amount of atoms and molecules that are present in the thermosphere receive extraordinary amounts of energy from the Sun, causing the layer to warm to such high temperatures as 1,500°C or higher. A person would not feel warm because of the extremely low pressure. Space shuttles flew and the International Space Station orbits in this layer, between 320 and 380 km.
5. Exosphere: It is 600-1000 km above the earth’s surface and is extremely thin, where the atmosphere merges into outer space. It is composed of very widely dispersed particles of hydrogen and helium present in very small amounts. This is the area where many satellites orbit the earth, receiving and giving information in the form of radio waves to all places on the globe.
Atmospheres of other planets:
According to Zia god energy theory, the sun and all planets etc formed from the same stuff as stars (sun is a star) and in a random way dependent on the concentration of hydrogen particles around it and the way they formed by nuclear reactions in its core and chemical reaction on its surface, therefore all are more or less different with different atmospheres. The atmosphere of Mercury has a thin layer mostly of oxygen, sodium and hydrogen . the atmosphere of Venus is thick and contains 96% of carbon dioxide. The atmosphere of Mars is thin and contains 95% carbon dioxide. Jupiter and Saturn’s atmosphere contains hydrogen and helium. Uranus and Neptune have hydrogen compounds like methane and ammonia in their atmosphere. Pluto has a 90% nitrogen atmosphere. The moon has 70% argon in the atmosphere.
Zia Ahmed Khan, email: khanziaahmed50@gmail.com
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