Origin of Earth, History of Earth, Evolution of Earth, Life on Earth, Geography of Earth
Earth is a beautiful planet where we live and it has variety of animals, plants and other organisms. The earth is part of a vast universe. As we know the Universe is about 15 to 20 billion years old and the earth is approximately 4 to 5 billion years old. But human beings evolved on earth around 2 million years ago. In this article, we will tell you the origin of Earth, how it got its own environment and how the Earth developed for human beings or how the human beings developed the earth’s resources for themselves.
Origin of Earth
The earth along with other planets and their satellites, the moon, many galaxies and the sun form the universe. Around the sun there are so many asteroids and comets in orbit, all are parts of the universe. Nobody knows where the universe ends because it extend much farther then can be seen by any powerful telescope. At night when we look up at the sky, we see so many points of light- most of which are stars. It is huge balls of bright and hot glowing gases. If you don’t know, the Sun is also a star. The distance of between the Sun and the Earth is about 150.8 million km. The Sun is the ultimate source of energy on Earth.
A solar system consists of a star in the middle with so many planets orbiting around it. Our Earth is a part of its solar system. It is one of the 8 planets of the solar system that has the sun in the middle and the eight planets orbiting around it. Recently there is believed to have nine planets that is Pluto. But on the basis of latest scientific work, it is no longer regarded as a planet of solar system.
Origin of Universe
‘Big Bang Theory’ is the most accepted theory of the origin of universe. This theory says, this universe started with a huge explosion and matter that is dust and gases filled with the entire space. When explosion happened the temperature of the universe was about 100 billion degree Celsius. It is believed that the Big Bang happened about 15 to 20 billion years ago. After that the vast collection of dust and gases begin to spin. When the gases and the dust spun faster, the centre became very hot and became the hot star Sun. From the edges of this ball of gas and dust, big blobs of dust broke off and formed eight ball shaped planets. It created our solar system. With an explosion our Earth was created about 4.5 billion years ago. It was a burning hot white mass of gas and dust.
Gas and dust gradually condensed to form solid rock over a long period of time. Because of that condensation and shrinking, the earth hit up much that the rock melted into a gluey liquid. The outer surface of the Earth which is also called earth’s crust cooled and formed hard rock again after million of years. The interior part of our earth is still very hot. The cooling and hardening of the molten matter and hot gases form the crust of the earth. With cooling of the earth the crust hardened and form the land. The process of cooling of the earth also condensed water vapour into liquid water filling the depression to form seas.
Origin of Earth
Our Earth with oceans, lush green forests and blue sky is the home to variety of organisms. This planet has its own unique atmosphere. The atmosphere helps to regulate the surrounding temperature which is necessary for supporting life. The Earth becomes hotter when it is dig a deeper hole. The temperature of the planet is hot enough to roast a human body at the depth of about eight km. About 32 km deep you would reach the part of the planet which is called mantle. This part is made of hard rock. The centre is called the core of the earth. It is approximately 6,400 km from the surface which have the temperature close to 5000 degree Celsius. Much of the core of the Earth is hot liquid.
We have already know that once every 24 hours the Earth rotates on its axis. The day and night cycle is of 24 hours. It’s axis is an imaginary line which pass through centre of the planet. The planet not only rotates on its axis but also revolves around the sun. The planet complete one full circle around the sun in 365 1/4 days. An orbit is the path along which a planet moves around the sun. As you know now, that the Earth revolves around the sun, the moon orbits the earth. The moon complete one circle in 27.33 days. As we know today, the moon is without air, water and life. Because of its blue oceans the earth look like beautiful bright bluish planet from the space.
Planets of the Solar System
1. Mercury- This planet is closest to the sun. It has a temperature range of 427 degree Celsius on its side facing the sun, and 270 degree Celsius on its back side. The planet has no atmosphere. It is also called Buddha.
2. Venus- This planet is the closest neighbour of the earth. It is about 40 million km away from the earth. Venus is an extremely hot planet which has it temperature of 480 degree Celsius. Its atmosphere has poisonous gases like carbon monoxide and Sulphur dioxide and it has 96% carbon dioxide. The planet is also name as Shukra.
3. Mars- This planet is also close to earth. Mars is name as the red planet. It has reddish dust and 95% carbon monoxide. It is believe to be a very cold planet and as of now presence of life on this planet has not been establish. The planet is also name as Mangal.
4. Jupiter- This planet is the largest planet of the solar system. Jupiter is mainly a rapidly spinning ball of gas especially clouds of ammonia and it has no solid surface. It is called Brahaspati.
History of Earth
5. Saturn- This planet is consist of helium and hydrogen. Saturn has a temperature of -184 degree Celsius and 90% nitrogen. The planet is also consist up of hydrogen cyanide which is a highly poisonous. It is characterize by a ring that surrounds it. It is also call as Shani.
6. Uranus- This planet is also considered very cold planet. It is 7th in order from the Sun and distant planet of solar system. Neptune and Uranus are the outermost planet of the solar system. It has a highly titled rotational axis. It is also call as Arun.
7. Neptune- This planet is much smaller than earth, dark and cold with its surface coated with frozen methane. It is also call as Varun.
8. Earth- This is the only planet known to sustain life.
What is Necessary for Sustaining Life
1. Presence of Water
We have already mention, during the evolution of the earth water vapour in the primitive atmosphere condens into liquid water. This process gave rise to the formation of oceans, freshwater bodies and rivers. If you don’t know, three-fourth of Earth’s surface is of water. Our life originated in water and it is a universal solvent. 90 percent of cell content is water and also two-third of a living organism consist of it. The biochemical reactions in living organisms required an aqueous medium. So, the water is necessary for the survival of living beings.
This planet is envelop by a gaseous atmosphere that sports life on it. The atmosphere of Earth consist of oxygen 21%, nitrogen 78%, water vapour, Ozone, small amounts of carbon dioxide and rare gases like neon, argon etc. Living organisms use oxygen from the atmosphere during respiration. It is important to oxidized food for liberating energy required for activities in the living beings. From the atmosphere green plants use carbon dioxide during photosynthesis.
16 degree Celsius is the average temperature of the earth. This temperature is the most comfortable for the living organisms to survive on the planet.
4. Buffering Capacity of Earth
The most important and unique feature of this planet is its buffering action due to which a neutral pH is maintain in the water bodies and soil. The neutral pH is necessary for the survival of the living beings.