EARTH

 EARTH.

Earth is the third planet from the sun and the only astronomical object known to harbor life .this is enabled by earth being a water world ,the only on is solar system sustaining liquid surface water .almost all of Earth's water in contained in its globel ocean,corering 70.8% of Eath's crust.the remaining 29.2%  of earth crust is land ,of wish is located in the from of continental land masses within one hemisphere,Earh's land hemisphere .most of Earth's land is somewhat humid and coverd by vegetation ,while large sheet of ice at Eath's polar deserts retain more water than Earth's ground water ,lakes,riversand,atmospheric water.combined Rath's crust and earthquakes Earth has a liquid outer core that generates a magnetosphere capable of deflecting most of the destructive solar ninds and cosmic radiation .

Earth has a daynamic atmosphere ,which sustain earth surface conditions and protects it from most meteoroids and UV- light at entry .it has a composition of primary nitrogen and oxygen .water vapor is widely present in the atmosphere ,forming clouds that cover most of the planet.The water vapor acts as a greenhouse gas and,together with other greenhouse gases in the atmosphere ,particular carbon dioxide ,creates the conditions for both liquid surface water and water vapor to persist via the capturing of energy from the sun's light.