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THE STORY OF EARTH

We all live on planet Earth, have you ever wondered how our planet Earth formed? how so many species came to existence? and how the modern humans evolved? In this article we have covered all those answers. At the end of this article you will be able to know the entire history of earth in a very little time. Do share it with your friends and loved ones.

1.FORMATION OF EARTH

  • About 4600 million years ago our solar system began forming within a concentration of interstellar dust and hydrogen gas called a molecular cloud or nebula.
  • The cloud contracted under its own gravity and our proto-Sun formed in the hot dense center.
  • The formation of the sun consumed more than 99 percent of the matter in the nebula. The remaining material began to unite into various masses.
  • The cloud was still spinning, and cluster of matter continued to collide with others.
  • Eventually, one of those clusters of matter grew large enough to maintain it's own gravitational pull, which shaped that into a planet which is known as Earth.

2.FORMATION OF EARTH'S CORE

  • About 4500 million years ago Earth's core formed.
  • Earth's core is the very hot, very dense center of our planet.The ball-shaped core lies beneath the cool, brittle crust and the mostly-solid mantle.
  • The core formed during accretion, as metal from impactors sank through a magma ocean to the center of the Earth.
  • Liquid metal in contact with liquid silicate equilibrated at high pressures and temperatures, resulting in the core and mantle compositions that we see in the Earth today.

3.FORMATION OF MOON

  • About 4425 million years ago Moon formed.
  • The Moon formed during a collision between the Earth and another small planet, about the size of Mars, called Theia.
  • The debris from this impact collected in an orbit around Earth to form the Moon.
  • During this massive collision, nearly all of Earth and Theia melted and reformed as one body.

4.FORMATION OF OCEAN

  • About 3800 million years ago ocean formed on earth.
  • Most scientists agree that the atmosphere and the ocean accumulated gradually over millions and millions of years with the continual 'degassing' of the Earth's interior.
  • According to this theory, the ocean formed from the escape of water vapor and other gases from the molten rocks of the Earth to the atmosphere surrounding the cooling planet.
  • After the Earth's surface had cooled to a temperature below the boiling point of water, rain began to fall—and continued to fall for centuries. As the water drained into the great hollows in the Earth's surface, the ancient ocean came into existence.

5.FORMATION OF LIFE

  • About 3700 million years ago life arrived on Earth.
  • The origin of life is a result of a supernatural event—that is, one irretrievably beyond the descriptive powers of physics, chemistry, and other science.
  • The earliest life forms we know of were microscopic organisms (microbes) that left signals of their presence in rocks.
  • The signals consisted of a type of carbon molecule that is produced by living things.

6.ACCUMULATION OF OXYGEN IN EARTH'S ATMOSPHERE

  • About 2330 million years ago oxygen began to accumulate in the earth's atmosphere.
  • The breathable air we enjoy today originated from tiny organisms, although the details remain lost in geologic time.
  • Scientists agree that oxygen, though lacking in the atmosphere at that time, was likely brewing in the oceans as a byproduct of cyanobacterial photosynthesis.
  • These microbes conduct photosynthesis: using sunshine, water and carbon dioxide to produce carbohydrates and oxygen.

7.THE FIRST VERTEBRATES(FISH) EVOLVED

  • About 530 million years ago the first fish appeared.
  • And then underwent a long period of evolution so that, today, they are by far the most diverse group of vertebrates.
  • The first fish were primitive jawless forms.

8.FORMATION OF LAND PLANTS

  • About 400 million years ago the first land plants evolved.
  • Oxygen in the atmosphere reacted to form ozone, which formed a layer.
  • This served as a protective barrier to the harmful rays coming from space and which allowed plants to colonise the land.

9.EVOLUTION OF LAND ANIMALS

  • With plants present on the land to provide a food source, animals rapidly followed.
  • Tetrapods are believed to be the first land animals.
  • The evolution of tetrapods began about 400 million years ago with the earliest tetrapods evolved from lobe-finned fishes.

10.EVOLUTION OF DINOSAURS

  • About 250 million years ago Dinosaurs were evolved from another group of reptiles called 'dinosauromorphs'.
  • Initially, Dinosaurs were the size of house cats, walked on all fours, and had long, skinny limbs like a greyhound.
  • But with time, abundance of oxygen and some other factors help them grew larger.
  • Eventutally they reached the top of the food chain.

11.EXTINCTION OF DINOSAURS

  • About 65 million years ago Dinosaurs went extinct.
  • An asteroid bigger than Mount Everest slammed into Earth just off the coast of Mexico's Yucatán Peninsula.
  • The collision was disastrous, triggering tsunamis that swamped vast swaths of coastline and firestorms that may have raged across the entire globe.
  • The impact also blasted huge amounts of dust and vaporized rock into the air, which, along with the soot from all those fires, blocked the sun for long stretches.This event led to the extinction of Dinosaurs.

12.EVOLUTION OF MODERN HUMANS

  • Modern humans (Homo sapiens) originated in Africa within the past 0.2 million or 200,000 years and evolved from their most likely recent common ancestor, Homo erectus, which means 'upright man' in Latin.
  • Homo sapiens evolved in Africa before migrating across the world.
  • About 10,000 years ago modern humans began settled agriculture.
  • Around 3,000 years ago humans learned to write.
  • To know more about the history of earth click here.