Indian politics
Indian politics

About Earth

  • The Earth is the third planet from the Sun .
  • It fifth largest planet in the solar system in terms of size and mass.
  • It is only the planet have water and atmoshapre .
  • It is called as blue planet due to presence of water.
  • The Earth is the only place in the known universe have life.
  • The Earth's shape is almost a Sphere.
  • It is bulges around the equator . Earth's diameter from North to South Pole is 12,800 kilometers, while through the equator it is 12,756 kilometers.
  • The time of Earth's day is increasing. When Earth was formed around 4.6 billion years ago, its day would have been roughly around six hours long.
  • Day time at earth is increasing by about 1.7 milliseconds every century.
  • The Earth orbits around the sun at a speed of 30 kilometres per second and takes 365 days (one year) to complete one full orbit.
  • The Earth is tilted 23.4 degrees on its ‘ imaginary axis’, joining North Pole to the South Pole.
  • The Earth’s radius is measures a huge 6400 kilometres length.
  • Earth’s atmosphere is a huge blanket of gases – mostly containg oxygen and nitrogen and wrapped around Earth.Which is protecting our planet from the sun’s strong rays.
  • The name Earth is given only 1,000 years ago. Name of all of the planets except for Earth based on name of Roman gods and goddesses. However the name Earth is a German word, which means “the ground.”

    • The Earth made up of three main layers: the crust, the mantle, and the core.

    The crust

  • The Earth’s outermost layer is called crust. It is rocky and rigid.
  • The crust splits into several tectonic plates & These tectonic plates are in relative motion one from another. On the basis of relationship and geologic setting, tectonic plate boundaries are of three kind : convergent (moving one toward the other), divergent (moving away from the other) and transformant (moving laterally).
  • These tectonic plates float on the soft upper mantle.
  • crust are of two kinds : continental crust, and ocean crust.
  • The thickness of the continental crust varies 50-70 km in case of the mostly made up of the rock granite.
  • The thickness of the oceanic crust varies from 5-30 km in case of the and mostly made up of the rock basalt.
  • The temperature of the crust increases when we go inside the eath , Its values lies in the range from about 200 °C to 400 °C at the boundary with the underlying mantle.
  • The outer portion of the crust is of sedimentary material and below that lie crystalline, igneous and metamorphic rocks .
  • The continental crust are made up of lighter silicates — silica + aluminium (also known as sial) while the oceans crust have the heavier silicates — silica + magnesium (also known as sima)
  • The crust floats on the mantle.
  • Continental crust floats little higher in the mantle than ocean crust because of the lower density of continental crust.
  • The land on Earth is made up by Continental crust , it is thicker (35 - 70 km), less dense and Oceanic crust makes up mostly beneath the ocean, it is thinner (5 - 7 km), denser
  • The crust makes up only 1% of the volume of Earth.

    • The Mantle

  • The mantle is the mostly-solid material of Earth's interior.
  • The mantle is about 83 % of the total earth’s volume and holds 67% of the total earth’s mass.
  • The mantle found from 35-2980 kilometers below Earth's surface.
  • The upper mantle lies in 7 and 35 kilometers below the surface of the Earth.
  • The mantle is composed of basically of magnesium, aluminum, silicon, and oxygen silicates.
  • It is denser than the crust but much less dense than Earth's core.
  • The temperature at the topmost layer of mantle ranges from 500 to 900 degrees Celsius and it increases with depth.

    • The Core

  • The main composition of Earth's core is that of iron alloyed with 5–15% nickel
  • The core of Earth is the very hot, very dense center of our planet.
  • The core lies about 2,900 kilometers below Earth’s surface.
  • The core has a radius of about 3,485 kilometers
  • The core is made of two layers: the outer core, which borders the mantle, and the inner core.(Outer Core - 2,200 km thick plus Inner Core - 1,230 to 1,530 km thick)
  • The NiFe (Nickel & Iron) alloy of the outer core is very hot,Temperature lies between 4,500° and 5,500° Celsius. Liquid iron and nickel layer presents in outer spins as the planet rotates and creates Earth's magnetic field & developed magnetic field helps earth to protect from the Sun's solar radiation. The outer core is very hot at up to 6,100°C and have thickness of 2,200 km .
  • The inner core is a very hot made up of of iron and nickel but the pressure is so high that it is shaped dense ball of (mostly) iron. It has a radius of about 1,230 to 1,530 km & Temperature in the inner core is about 5,200°-5500°C Celsius . The pressure of core of Earth is nearly 3.6 million atmosphere (atm).

    • The Atmosphere

  • The atmosphere is a huge blanket of gases covering the earths & keeps us warm, gives us oxygen to breathe.
  • The Earth'atmosphere commonly termed as air.
  • It extend up to 10000 kilometers above the Earth's surface in it's thinnest regions.
  • Earth's atmosphere is composed of about 78 percent nitrogen, 21 percent oxygen, 0.9 percent argon, and 0.1 percent other gases.
  • The atmosphere is composed of five layers based on temperature and desity of consitutent gases. These layers are termed as the troposphere, the stratosphere, the mesosphere, the thermosphere,(the ionosphere) , and the exosphere

    • The altitudes of the five layers are

  • Exosphere: 700 to 10,000 km
  • Thermosphere: 80 to 700 km
  • Mesosphere: 50 to 80 km
  • Stratosphere: 14 to 50 km
  • Troposphere: 0 to 14 km

    • Layers of atmosphere

    Exosphere:
  • The exosphere is the outermost layer of Earth's atmosphere.It extends from 700 to 10,000 km .
  • The exosphere is mainly composed of extremely low densities of hydrogen, helium . The atoms or molecules are so far apart that they can travel hundreds of kilometers without colliding with one another.
  • It gradually changes into the vacuum of space. The layer just below the exosphere is the thermosphere.
  • The boundary between these i.e exosphere & thermosphere two layers is called the thermopause.
  • The bottom of the exosphere is sometimes also called as the exobase.
    • Thermosphere:
  • The thermosphere is a layer of Earth's atmosphere which is just above the mesosphere and below the exosphere.
  • It extends from 80 to 700 km & considered as the fourth layer of the earth's atmosphere.
  • Its temperature changes with solar activity. This layer has a sub layer known as ionosphere that reflects the radio waves .
    • Mesosphere:
  • The Mesosphere is one of the coldest layers of the atmosphere with a temperature rising up to -90 degree celsius
  • Meteors get burn up in this layer
  • The mesopause is also called as the Karman line ( nearly 100 kms above Earth's . It is considered begining of the space ).
  • In the mesosphere temperatures decrease with altitude. Because This layer contains few gas molecules which can absorb the Sun’s radiation. The main heat source is the stratosphere below to this layer.
    • Stratosphere:
  • Stratosphere is very beneficial as it has ozone layer (ozonospare ) which absorbs the Ultraviolet (UV) radiations from the Sun and protects life on Earth
  • This layer found warmer than Troposphere and has a temperature of around 4 degrees celsius .
  • The atmosheric layer provides ideal conditions for flying fighter jet planes or coomercian planes because it is free from clouds and weather phenomena.
  • It’s a very stable layer, with little air circulation. due to this reason, commercial airlines tend to fly in the lower stratosphere to keep flights smooth.
    • Troposphere:
  • The Troposphere is lowest layer of the atmosphere starts at the ground.
  • The Troposphere at the equator thickest (14 kilometers) & thinnest above the poles, just 8 kilometers.
  • It contains as much as 80 percent of the total mass of the whole atmosphere.
  • Tropo’ means Change, as almost all the weather phenomenon take place in this layer of atmoshare.
  • Troposphere is warmer at base & density of the air decreases with an increase in heigh.
  • Tropopause: It is the maximum height from where the temperature stops decreasing. The temperature region as low as -58 degree celsius.

    • FAQ about our Earth

    What is the exosphere?

    Answer: The exosphere is the outermost layer of Earth’s atmosphere.

    Which layer do most planes fly in?

    Answer: The stratosphere is the second layer of the atmosphere where the planes fly in.

    Which is the coldest layer of our atmosphere?

    Answer: The mesosphere

    What layer is the ozone in?

    Answer: The stratosphere

    Which layer does the weather occur?

    Answer: The Troposphere

    Which is the largest ocean on earth?

    Answer: The Pacific Ocean

    Which are the two main metals found in the earth’s core?

    Answer: Iron and nickel

    Which is hotter, the center of the earth or surface of the sun?

    Answer: The center of the earth