[Music] hey kitty look a 17 year old intern at nasa has discovered a new earth-like planet isn't that brilliant i understand your curiosity kitty but one day we might be able to settle on a different planet but it's possible only if the new world has all the four major domains of earth present on it it's doming kitty hey friends it is rightly said that heaven is under our feet and over our heads but no wonder we fail to acknowledge it so in today's episode let me tell you about those four major domains of the earth that make our earth indeed a heaven zoom in so what are the four domains of earth the massive universe formed millions of years ago has infinite undiscovered spaces trillions of stars millions of galaxies and the nine planets in our solar system but the universe blessed planet earth with living beings and to make life possible three different components meet so humans can survive and thrive these are the elements of land water and air these are nothing but the domains of the earth namely the lithosphere hydrosphere and atmosphere which give rise to the biosphere let's have a good look at each of them starting with the lithosphere and to know about it let's speak a little beneath the earth's surface as you can see it is made up of various layers out of which the crust and the upper layer of the mantle make the lithosphere which is basically the solid portion of the earth the lithosphere is further divided into two parts the continental crust which is the thick part of the earth's crust which forms the large land masses and the oceanic crust that could be found deep under the ocean and seas which are denser than the continental crust now let us move further to learn about the hydrosphere [Music] you see although the earth seems hot and burning from inside but when you look at it from space you'll see one soothing cool planet due to its blue shade as around 71 of the earth's surface is covered by water and this water-covered area is called the hydrosphere this 71 of the water is found in three different forms that is water located in a liquid state into the water bodies such as oceans seas lakes ponds etc in a solid state such as ice and gaseous state such as water vapor but always remember that out of the 71 of available water only 2.5 is consumable by humans so it is advisable that you consume water wisely and not waste or contaminate it [Music] now let us move further and look at the sky i know you feel that the area between the surface of the earth and space is a vacuum or there is nothing in between but let me inform you that a lot is happening there as it is covered with a set of layers of gases we call the atmosphere that surrounds the earth this invisible shield of gas performs various duties like keeping us warm providing the oxygen and it is where the weather changes the atmosphere is further composed of different layers and each layer has its prominence the first layer is the troposphere the lowest layer of atmosphere that ranges up to five to nine miles above the earth's surface and is denser than other layers the troposphere is where all of earth's weather occurs and contains approximately 80 percent of the total mass of the atmosphere now as we move ahead up to 31 miles from the earth's surface we enter the stratosphere this vital layer absorbs harmful uv rays coming from the sun towards the earth with the help of the ozone layer present in it the next layer is mesosphere where meteors rushing with a high speed gets burnt up and after that comes the thermosphere where the solar radiations are absorbed and you can witness the aurora in the same layer and the last layer is exosphere which meets space now coming back to the fourth domain of earth that brings all the elements such as land water and air together is our last sphere the biosphere the biosphere represents every part of earth where living organisms are found that could be commonly divided into two main parts the plant kingdom and the animal kingdom this sphere ranges from the vast sky to the base of the enormous water bodies such as oceans it is believed to be formed millions of years ago where the first living organism to be created was bacteria so here we go friends these are the four domains of the earth we need to survive and thrive on this vast universe and the earth is the only planet to be blessed with it so cherish it nourish it and make sure not to do anything to perish it because this is the only home we have our beloved planet earth trip your time did you know scientists claim that the earth is approximately 3.7 billion years old which also makes the biosphere to be almost the same age also researchers say that the depth of the biosphere is complicated to measure [Music] as there are fish known to be living as deep as 8 372 meters in the puerto rico trench hope you learned something new in today's episode until next time it's me dr binox zooming out [Music] ah never mind