The planet earth surface is covered by almost 70% of water and rest 30 percent constitute solid surface like continents, islands, mountains.
Hence when we see earth from space it looks like blue planet because the visible light radiation coming from the son contains VIBGYOR means violet,indigo, blue,green, orange and red, they together form white light.
But when white light falls on earth surface it’s water resorvoier absorbe the other wavelengths of light except blue and only blue light reflected back to space, that’s why we see earth as blue planet.
Why Earth is called blue planet,to know it in detail we have to first know about the origin of earth and it’s topogargical factors,so students lets see why earth is called blue planet.
About 20 billions years ago an unimaginable natural fanomenon happened called “BIG BANG”.
The big bang theory is given by American scientist GEORGE Lemaitre, according to him about 20 b.y.a a huge explosion happened in our vacant and empty space which have tremendous power and mass with huge temperature and light.which lead’s for the the formation of univerce and galaxies, Star system, planets, natural setelytes, steroids gas cluster and other unknown things present in today’s time in our vast univerce.
Scientists also say after big bang our universe is expending every second of time.till now it expends as much as we can’t even imagine its end and bowder line, in one word it is beyond our imagination. Like we also don’t think where the ends of our thoughts.
So the most probable and pet question you ever ask, where we are in this vast dark deep space.so students don’t worry I’m here to eradicate your all confusion and misconceptions.
Thair are millions of galaxy in our universe but our home galaxy is Milky way galaxy contains billions of Star system,in this a star system present called solar system,here our home planet Earth is present.
Solar system constitute 8 planets including Earth, more then 200 moons, steroids and gas clusters.
Our main location is earth it is 3rd distance and 5th largest planets from sun in our solar system having habitual environment and sufficient amount of life supporting gases and elements are present.
Earth’s atmosphere contains 78 percent nitrogen and 21 Percent oxygen,and traces of other gases like carbon dioxide,argon etc.
Only Earth have oxygen in sufficient amount for keeping life on earth, otherwise no other planets in our solar system contains oxygen and life supporting elements in sufficient amount.
Among all metals we known till now iron constitute about 34.6 Percent and this is the reason for which earth have very strong magnetic field.
For your kind information students, Neptune a planet of solar system is also looks like blue in colour but it doesn’t means Neptune contains water,the whole planet Neptune is made up of ice having harce environment for survivality of human being.
– universe originated about 20 bya.
– solar system and Earth were formed about 4.5 bya.
– Life appeared around 4 billion years ago.