We live on Earth, which is the only planet known to harbor life. It also has lots of water on its surface and contains many outstanding features. So, let’s find out Earth’s specialties!
Basic Information
Firstly, Earth is our home planet and is the third planet from the Sun. Its distance to the Sun is 150 million kilometers, making it within the habitable zone of our star. It’s also the only place known to harbor life because no alien life is found yet.
Secondly, we have to discuss their radius and mass. It has a massive 5,974,000,000,000,000,000,000,000 kilograms of matter, so we abbreviate the humongous value to “1 Earth mass”. Moreover, it is 12,742 kilometers wide, making it the largest terrestrial planet in the Solar System. Earth is the densest planet in the Solar System, with 5.513 grams per cubic centimeter.
It goes around the Sun in 365.25 days, and it sprints at 30 kilometers per second across the Solar System. That’s the reason for an additional leap day every 4 years. Additionally, its rotation period is a bit less than 24 hours, but the distance moved relative to the Sun fixed the problem.
Image Credit: Canva
Why does our planet have seasons? Earth’s axis is tilted for 23.4 degrees compared to the Sun’s orbit! When one hemisphere is facing the Sun more, it faces summer. On the contrary, the area faces winter. This cycle applies to all other planets, too!
The Atmosphere
Earth has a thick atmosphere with substantial air pressure and mass. It provides us with enough air to breathe and powers all wind power equipment. So, what are its composition and features?
The Composition
You’ll be surprised if you don’t know about our atmosphere — it’s not oxygen-dominated. Instead, 78% of the air surrounding us is nitrogen (N2). Only 21% of the atmosphere is oxygen, an essential element for breathing.
If you calculate the figure, you’ll find out that 1% of the atmosphere is not the two elements, and the other elements and compounds are trace gases. Common ones include carbon dioxide, nitrogen dioxide, and water vapor. We are adding many harmful greenhouse gases to Earth’s gaseous library, and that action leads to climate change.
Image Credit: Canva
The Layers of the Atmosphere
The atmosphere contains five layers:
- The troposphere
- The stratosphere
- The mesosphere
- The thermosphere
- The exosphere
Let’s explain them one by one.
The Troposphere
This layer of the atmosphere begins at Earth’s surface and extends to 8 to 14 kilometers high. This section has all weather on Earth and is where clouds appear. Also, 75% of all mass of the atmosphere settle down on this portion due to higher air density.
Image Credit: Canva
The Stratosphere
The following layer is the stratosphere, which is above the troposphere. This layer is also where ozone protects our planet and all its living organisms from harmful solar radiation.
Mesosphere
The mesosphere is probably the least-known portion of the atmosphere. It’s above the stratosphere but beneath the thermosphere. But, it plays a role in meteor showers: Asteroids usually burn up in that area because the air pressure significantly increases when you travel from outer space.
Image Credit: Canva
Thermosphere
The thermosphere is the hottest layer of the atmosphere, hence the name, right? No! The particles in the layer are so light that heat cannot transfer effectively through the layer. The International Space Station can comfortably fly there.
Exosphere
The exosphere is considered as part of outer space, but is more compact than the usual “vacuum” in space. In fact, the boundary of the exosphere is fuzzy but is at about 10,000 kilometers from Earth’s surface, according to NASA.
Earth’s Structure and Surface
Earth’s surface contains a lot of water, as mentioned before. The figure is approximately 71%. Therefore, only 29% of Earth’s surface is land. The highest point on Earth’s surface is over 8,800 meters from sea level on Mount Everest. Oppositely, the Mariana Trench is the deepest point on Earth, covered by the ocean.
So, let’s talk about Earth’s inner structure. Like other terrestrial planets, Earth has a crust, mantle, and core. The thin crust contains about 47% oxygen, 28% aluminum, and smaller amounts of other substances. However, Earth’s core is dominated by nickel and iron. The mantle is the thickest layer of Earth’s interior, at around 2,900 kilometers thick.
Interestingly, Earth’s core is also split into the outer core and the inner core. The outer one is liquid, while the inner one is hard. In fact, the outer core creates the magnetic field that protects Earth from solar wind by diverting or trapping the charged particles.
Conclusion
So, we talked about Earth’s many features here, including its background information, atmosphere, and interior. Earth science is a great subject to learn, so we’ve just touched the very basics. Remember that you can know more in the references.
References and Credits
- (2019, December 19). In Depth | Earth – NASA Solar System Exploration. Retrieved December 27, 2020, from https://solarsystem.nasa.gov/planets/earth/in-depth/
- (n.d.). How much does Earth weigh and how is this measured | Cool Cosmos. Retrieved December 27, 2020, from https://coolcosmos.ipac.caltech.edu/ask/61-How-much-does-Earth-weigh-and-how-is-this-measured-
- Elizabeth Howell. (2018, June 23). How Fast Is Earth Moving? | Space. Retrieved December 27, 2020, from https://www.space.com/33527-how-fast-is-earth-moving.html
- Tim Sharp. (2017, October 13). Earth’s Atmosphere: Composition, Climate & Weather | Space. Retrieved December 27, 2020, from https://www.space.com/17683-earth-atmosphere.html
- (n.d.). By the Numbers | Earth – NASA Solar System Exploration. Retrieved December 27, 2020, from https://solarsystem.nasa.gov/planets/earth/by-the-numbers/
- (2019, June 28). Troposphere | NASA Space Place – NASA Science for Kids. Retrieved December 27, 2020, from https://spaceplace.nasa.gov/troposphere/
- (2019, June 28). Stratosphere | NASA Space Place – NASA Science for Kids. Retrieved December 27, 2020, from https://spaceplace.nasa.gov/stratosphere/
- (2019, June 28). Mesosphere | NASA Space Place – NASA Science for Kids. Retrieved December 27, 2020, from https://spaceplace.nasa.gov/mesosphere/
- (2019, June 28). Thermosphere | NASA Space Place – NASA Science for Kids. Retrieved December 27, 2020, from https://spaceplace.nasa.gov/thermosphere/
- (2019, June 28). Exosphere | NASA Space Place – NASA Science for Kids. Retrieved December 27, 2020, from https://spaceplace.nasa.gov/exosphere/
- Tim Sharp. (2017, November 14). Earth’s Layers: What Is Earth Made Of? | Space. Retrieved December 27, 2020, from https://www.space.com/17777-what-is-earth-made-of.html
Image Credit: NASA’s Eyes