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27 Interesting Facts About Earth’s Atmosphere

[Estimated read time: 7 minutes]

The shiny blue marble (Earth) has fascinated us since we have first begun to walk across its surface. Till now, it remains the only planet we know of where life exists. Over the past few centuries, we have learned much about Earth, but how much does an average person really know about this planet?

How much do you really know about the atmosphere surrounding you? Now you probably have tons of facts rattling around in your brain. Check out what we have collected – The 27 interesting facts about Earth’s atmosphere that you may or may not know.

1. Mixture

The Earth’s Atmosphere is 480 km thick, and it is made of a mix of about 16 gases. The gases in Earth’s atmosphere include

Carbon dioxide 0.035
Neon 0.0018
Helium 0.00052
Methane 0.00017
Krypton 0.000114
Hydrogen 0.000053
Nitrous oxide0.000031

Other gases are Carbon monoxide, Sulfur dioxide, Nitrogen dioxide and Ammonia, which occupy 0.00003 percent of Earth’s atmosphere.

2. The Five Layers

The atmosphere is divided into 5 layers:

  1. Troposphere is the layer closest to the Earth’s surface. It is 7 to 20 km thick and contain’s half of the Earth’s atmosphere.
  2. Stratosphere starts above the troposphere and ends about 50 km above ground. Planes fly in this layer to avoid turbulence and cover more distance using less fuel. 
  3. Mesosphere starts at 50 km and extends to 85 km high. It is the coolest part of atmosphere with temperature averaging minus 90 degree Celsius.
  4. Thermosphere extends from 90 km to between 500 and 1000 km. Temperature can get up to 1500 degree Celsius. This is where space shuttle flew.
  5. Exosphere is the highest layer, and widely contains particles of hydrogen and helium.

3. High Altitude, Thin Atmosphere

As the altitude increases, the atmosphere becomes thinner and thinner. The air pressure in the Exosphere (highest layer) is extremely low due to its high altitude and the distance between the molecules it has.

4. Karman Line

According to the Federation Aeronautique Internationale, an altitude of 100 km above the Earth’s sea level represents the boundary between atmosphere and outer space. This border is called Karman line.

5. Troposphere is Denser

The lowest part of the troposphere is the warmest section of the layer, and it is denser than all its overlaying layers because a larger atmospheric weight sits on top of the troposphere and causes it to be most severely compressed.

6. Earth’s Temperature is Rising

Image credit: emaze

The global climate has warmed and cooled throughout history. At present, we are seeing unusual rapid warming. This is due to greenhouse gases, which are increasing because of human activities, and they are trapping heat in the atmosphere.

7. Ozone Layer

Image credit: wikimedia

One of the most essential things in the atmosphere is the Ozone layer. It is 19-32 km above the Earth’s surface. It’s a pungent smelling blue gas that absorbs most of the sun’s ultraviolet radiation.
In 1985, the hole in the ozone layer was discovered above the Antarctic. It has improved following a ban of the used of Chlorofluorocarbon.

8. Chlorine Affects Ozone

A single atom of chlorine can destroy more than hundred thousand ozone molecules. This deterioration lets a huge amount of ultraviolet B rays to reach Earth that can cause skin cancer and cataracts in humans and harm animals as well.

9. The Northern Light

Image source: Nasa 

Aurora(s) (also called polar light) are seen in the high latitude regions. They are shimmering curtains of light seen at night. They are formed due to charged particles from the Sun striking the upper atmosphere above the poles.

10. Why Earth Appears Blue?

Image source: Nasa

Sunlight is scattered in all directions by all the gases present in Earth’s atmosphere. Blue light is scattered more than other color because it travels as shorter, smaller waves. This gives Earth a blue halo when seen from space onboard ISS at height of 402 to 424 km.

11. Temperature at Each Layer

Image source: britannica.com

The temperature at different layers of Earth’s atmosphere depends on humidity, solar radiation and altitude. The coldest temperatures can be found near the mesopause (85 km – 100 km above Earth’s surface). In contrast, warmest temperatures lie in the thermosphere that receives strong ionizing radiation.

12. Meteors Burn up in Atmosphere

Meteors burn up in Earth’s coldest atmosphere – mesosphere layer. As meteor begins to enter this layer, it immediately bumps into molecules of the mesosphere and scrapes against them, causing high friction and rapidly generating heat due to the meteor’s speed. It begins to glow and chips of the rock start to fly off.

13. Acidic Rain

Image credit: buzzle

Acid rains are formed by a chemical reaction that begins when sulfur dioxide and nitrogen oxides combine in the atmosphere with water vapors. The resulting acid rain is capable to destroy animals and plants, and entire forests. If it reaches lakes or river, it destroys all the organisms living there.

14. Ionospheric Layer

Image source: astrosurf

The ionosphere is a region of upper atmosphere from 60 km to 1000 km altitude, which covers thermosphere, and parts of the mesosphere and exosphere. It is charged by radiation coming from the Sun. Ionosphere plays a crucial role in radio signal propagation around the Earth.
Geomagnetic solar storms caused by solar winds and solar flares can disrupt activity in the ionosphere, which can cause difficulty with radio signal transmission and global positioning system signals.

15. Earth’s Magnetosphere is Strongest

Image source: Nasa

Earth’s magnetic field reaches 58,000 km into space and this region is called magnetosphere. It prevents most of the particles from the Sun, carried in solar wind, from hitting the Earth. The Sun and other planets have magnetospheres but the Earth has the strongest one of all. The Earth’s south and magnetic poles reverse at irregular intervals of hundreds of thousands of years.

16. Nature of Exosphere

The exosphere doesn’t behave like a gas, because molecules are so far apart that they can travel hundreds of miles without colliding with each other, and particles constantly escape into space. These free moving particles follow ballistic trajectories.

17. Contrails

Image source: wikimedia

You may have seen jets leaving white condensation trails. This is formed when the hot, humid exhaust from the engine mixes with the colder air outside. Water vapor from the exhaust freezes and becomes visible, exactly like your warm breath in a cold weather.
A thick, persistent contrail signals high humidity or may mean a storm is coming. Opposite to this, a thin and rapidly disappearing contrails means the air at high altitudes is low in humidity.

18. Contaminated Air

Approx. 20 percent of the world’s population breathes severely contaminated air, especially with sulfur dioxide and carbon monoxide resulting from industrial operations. This raises the number of respiratory problems, especially amongst elders and children. 13 percent of the British children suffer from asthma caused by air contamination.

19. Total Amount of Water in Atmosphere

The atmosphere contains 37.5 million billion gallons of water at any specific moment, in the invisible vapor phase. This is enough to cover the entire Earth’s surface with one inch of rain. Moreover, this amount of water is recycled 40 times each year, which means a water vapor molecule has an average residence time in the atmosphere of only 9 days.

20. Energy Required to Evaporate Water

600 calories of energy is required to evaporate each gram of water. When the same gram of water condenses back into liquid, the same amount of energy is released back into the atmosphere.

21. Trade Winds

Image credit: wikimedia

The trade winds blow in the warmest parts of the Earth, between 23.5°S and 23.5°N. This is the reason most thunderstorms and monsoons originate in these volatile regions. The weaker the trade winds become, the more rainfall can be expected in the neighbor landmasses.

22. Earth’s Atmosphere is Leaking

Image source: dailygalaxy

Earth is losing its atmosphere continuously – Every day, approx. 90 tonnes of material escapes from upper atmosphere and streams out into space. However, 90 tonnes per day amounts to a tiny leak. Earth’s atmosphere weighs 5 quadrillion tonnes, so we are in no danger of running out any time soon.

23. Why Sunset Appears Red?

At sunset, most of light rays are reflected and scattered in the atmosphere and the sun appears dimmer. The color of the Sun itself appears to alter, first to orange and then to red. This is because more of the short wavelength green and blue are scattered and only longer wavelength red and orange are left to be seen. That’s why sun set appears red.

Read: 13 Very Interesting Questions with their Answers | Explained

24. Alive Microbes

paper published in the journal Proceedings of the National Academy of Sciences shows that there are many different types of microorganisms present in the atmosphere 8 to 15 km above the Earth’s surface. Many of the microbes discovered high in the sky are similar to those in the oceans and freshwater environments. About 25 percent of the microbes were similar to those found in feces.

25. Heat from Lightning

A single stroke of lighting bolt can heat the surrounding air to 27,000 degree Celsius. Since the lightning takes so little time to travel, the heated air has no time to expand. This rapid heating causes an explosive expansion of the nearby air, which forms a shock wave of compressed particles in every direction. Similar to explosion, the rapid expanding waves create a very loud, booming burst of noise.

Read: 28 Gripping Facts About Gravity

26. Refractive Index of Air

The refractive index of air is slightly greater than 1. Variations in refractive index can lead to the blending of light rays over long optical paths. The refractive index of air depends on temperature. Refraction effects rise with the increase in temperature gradient. Mirage is a perfect example.

27. Breaking Sound Barrier

Image: Brian Nevins/Red Bull Content Pool

Read: All Interesting Facts About The Earth’s Moon

In 2012, Austrian skydiver Felix Baumgartner jumped from a helium balloon at 37 km altitude (upper stratosphere). He initially free-fell in the low pressure atmospheric level at a rate faster than the speed of sound, reaching a top speed of 1358 km per hour, or Mach 1.25. Doing so, he became the first person to break the sound barrier without vehicular power. As he fell, the air thickened, helping to slow him down.