Essay on Earth for class 5
The Earth is the planet in which we live in. It is the only planet which is known to sustain life in the entire solar system. on terms of the distance measured from the Sun, the Earth is the 3rd planet. It was formed 4.5 billion years ago.
Concept of movement of the Earth
Like other planets, the Earth too moves around the Sun in a well-defined path called the orbit. To make the complete path, it takes 365 days for the movement around the Sun. This movement is called revolution. Also, it moves around its own axis called the orbit. This movement called the rotation takes 24 hours. This is the reason why we have days and nights on the Earth. The precise time for the revolution is 365 and 1/4th days. That’s why after every 4 years we have a leap year of 366 days.
The Earth is about 150,000,000 km away from the Sun. This distance is measured in Astronomical Unit (AU). The average speed of the Earth with which it moves in its orbit is 30 km/s. The moon goes around the Earth for the average distance of 4,00,000 km.
The Earth along with the other planets of the solar system was formed 4.5 billion years ago. The exact cause of the formation is still not yet clear. Many different scientists explain in different ways. However, the most accepted theory is that the planets formed after a great Big Bang explosion that occurred at that time. The great explosion made way for the formation of large masses in the solar system which are today called as planets and asteroids.
Earth’s water came from various places in the solar system. The water vapour condensed, glaciers melted and thus large bodies of water were formed. This water bodies consist of 70% of the Earth’s total mass. they sustain a large variety of life as ecosystem.
Some bacteria after the formation of the Earth developed photosynthesis which allowed plants to capture the energy from sunlight and make food using water from the soil. this led to the release of huge amount of oxygen in the atmosphere which allowed for the growth and sustenance of aerobic life on the Earth.
After the formation of Earth, the entire land was just a single piece of landmass. However, the large landmass began to get separated as many earthquakes, volcanoes, tsunamis etc began to take place. This in turn made the tectonic plates of the Earth collide with each other which the edges of the plates to brush against each other and change the composition. This led to the formation of continents and then the smaller countries. A group of countries is called a continent.
What is the Earth made up of?
The surface of Earth is rocky. It is the rockiest among all the planets in the solar system. It is a mixture of various components. Let’s see the detailed description —
Earth is made up of iron (32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulphur (2.9%), nickel (1.8%), calcium (1.5%), and aluminium (1.4%). Apart from these chemicals there are few traces of various chemicals present in the surface of the Earth’s crust.
The chemicals components vary as we move from the innermost part of the Earth (core) towards the outermost part (crust). The core mainly comprises of iron (88.8%), nickel (5.8%), and sulphur (4.5%). The crust is mainly oxygen which combines with other components to form valuable products.
Shape of the Earth
The shape of the Earth is spheroid, not a perfect sphere. It is squashed at the top and bottom part. Hence, to be precise, the shape of the Earth is oblate spheroid. As the Earth rotates on its axis, the centrifugal forces acting on the Earth make the equator move out a little and pulls the poles closer towards the centre. Thus, it makes it as spheroid.
Inner parts of Earth
The Earth’s crust is solid but it is made up of parts which move slowly. The hard rock on the outside of the Earth lies on top of hot liquid material below it in the deeper mantle. This liquid material keeps on moving because it gets heat from the hot centre of the earth. This slow movement of the plates is the reason of earthquakes, volcanoes and various other natural calamities that occur on the Earth.
The plates are called as tectonic plates. They are of 2 types. One type of the plates is convergent i.e. they keep on moving towards each other. this is the reason of formation of countries like Japan and the mountains like the Himalayas. The other type of plates moves away from each other i.e. they are divergent. The Great Rift Valley in the African subcontinent is the result of this type of plates.
Surface of the earth
The surface of the earth is uneven. As I already mentioned above, the surface is rocky and constitutes chemicals and water. The reason of the surface being uneven is because of the presence of various types of landforms. We have tall standing mountains like the Himalaya, deep oceans like the Pacific Ocean, Tibetan plateau, plains like the northern Indian subcontinent, low lying valleys like Kashmir etc. In addition to these, the plates are always colliding and thus this paves way for the generation of newer types of landmass. However, not all of these landmasses are suitable for living.
There is an estimated about 7 billion people living on Earth. They live in more than 200 different lands spread across the globe called countries. A country like Russia is large which comprises of many large cities. Moreover, Russia itself has 12 different time zones which have been made to cater to the vast number of people across the country. Others, for example like the Vatican City are small. It is smaller than the largest metros of India. The 5 most densely populated countries are China, India, United States, Indonesia, and Brazil. About 90% of people live in the northern half of the world above the equator which has most of the land. Scientists and Historians think that people originated from the country of Africa. However, now people have moved out of Africa and are spread unevenly across the length and breadth of the world.