Earth, A Short Introduction

Earth Earth is a planet located at third place in our Solar System which is located in a galaxy known as "Milky Way" containing about two hundred billion stars and is about one hundred thousand light years across. The Milky Way itself is one among three dozen galaxies of the so called "Local Group". The Local Group is further part of Virgo Cluster which itself is part of Lanikea Supercluster. One step further and we find ourselves staring at the cosmic web of galaxy Superclusters which we call the universe. It is theorised that our universe itself may also be part of a universe of universes, perhaps many billions of them, a multiverse. Let's come back to our dear planet again. It's a huge ball of rock and metal having a diameter of roughly eight thousand miles. It weighs a crazy 6 septillion tons or six thousand million million million tons! The most distinguished quality of this planet is that it has water. Thanks to science, I can tell you how much water does it have. That is, wait for it, 1.35 million trillion tons! As you know very well that life as we know it so far can't exist without water. So, it is also the only planet that harbours life. I read in some science journal that the earth is losing its water very very slowly. Which means that we will one day run out of water. But that day is expected to come in next three and a half billion years from now. So, you don't have to be super worried about it. Now, we move towards how old is our earth. Believe me, it's much older than you thought or told by the Holy Bible. It's a whopping 4.57 billion years old! Told ya! One more distinguishable feature it has is its Oxygen based atmosphere which again is essential for living organisms except for plants. The atmosphere comprises of 78% Nitrogen, 21% Oxygen, 0.04% Carbon Dioxide and trace amounts of some other gases. As a whole we call it air. It might not seem too heavy but it also carries weight and you won't believe if I tell you that the air around the earth is about 5 million billion tons! Overall area of earth is about 197 million square miles of which only 29% or 57 million square miles is land, the remainder being covered with oceans. The land is fractured into huge chunks, we call continents. There are seven of them i.e Asia, Africa, North America, South America, Antarctica, Europe and Australia. Human population of our planet is currently about seven and a half billion.