Our planet Earth is one of the eight planets of our solar system, which lies in the Milky Way Galaxy. Just a simple sneak-peek into Wikipedia of the Milky Way says that “it is estimated to contain 100–400 billion stars and at least that number of planets.” Coupled with the knowledge that there are billions of galaxies out there in the Milky Way in the universe, we can skip the math on the possible total number of planets out there in the universe.
And yet, the only planet to have life – or at least the one that we know of – is our planet Earth. Therefore, in that light, Earth seems to be both stupendously insignificant and remarkably significant at the same time.
But before we dive in to the subject about the origin of the Earth, it is essential to have a slight understanding about how our solar system came to be.
It is estimated that our solar system was formed about 4.5 billion years ago from a dense cloud of gas and dust in the universe. When this cloud collapsed – possibly due to the shockwaves of the nearby exploding star (which is known as a supernova) – a solar nebula was formed, which is basically a swirling disk of material.
As the gravity started pulling more and more materials towards the center, the Hydrogen atoms began combining to form the Helium atoms, releasing tremendous amounts of energy and creating our Sun.
Matter further down the disk also started colliding with each other, forming planets, dwarf planets, and moons. The smaller leftover pieces became asteroids, comets, and meteoroids (which are basically other objects wandering in the Universe that are not planets and moons, to put it simply.) And hence our planet Earth was formed along with other planets in our solar system.
When Earth was first created, it was just a hot burning mass of energy. Slowly, the burning mass cooled down and mellowed. However, it was nowhere near to the habitable sweet-home planet that we have as today. In fact, not even remotely close.
Full of volcanic activities, lava, chemicals, and number of other hostile materials that you could think of, and on top of that enveloped in a blanket of methane, ammonia and carbon dioxide – gases that are far cry from what we actually need in order to survive – Earth was a different being altogether.
So, how did our Earth went from being a place where no life was possible to being the planet that oversaw hundreds of years of civilization and development?
Next up, we will look at “how on earth” did life really start?