ORIGIN OF THE PLANET EARTH, BLUE PLANET
ORIGIN OF THE EARTH
The origin of the earth its composition and history are a part of the subject matter of the science of the geology. From the geological point of view the formation of the solid crust of the earth is taken as the beginning of its history.
According to some common belief the earth has been formed from the Sun. Most of the theories concerned with the origin of the earth. Those emphasize that the planet originated as a hot gaseous mass, which on cooling turned into liquid and then then into a solid mass. Some theories consider earth as having been formed through the solidification of a ring. The ring was thrown away by a cooling and rotating nebula . This ring was on the series of such rings that condensed to form various planets.
The crust of the earth as we see is solid. Hence, there has been considerable difference of opinion about the state of matter that formed the earth initially. A theory considers the earth originated as a hot mass and cooled slowly to develop a solid crust. The inner part of the earth from which the heat loss was slow, is still in a liquid state. Other theories also conveys that the earth originated as a solid mass. Due to the decay of the radioactive elements in its interior and the pressure of the overlying strata that keeps the interior of the earth in a liquid state.
On the basis of density, the denser matter forms the central part of the earth. The surface part are made of lighter material. So, the rocks forming the surface layer are lighter material called “Sial”(silica and aluminium), while the denser part called “Sima”(silica and magnesium) and “Nife”(nickel and iron). However further experiments proved that around 4.6 billion years ago the earth was formed.
Finally,”ORIGIN OF THE PLANET EARTH, BLUE PLANET” is the title where we were discussing about this planet and its formation. It is the only planet where life exists with various changes and will continue to go on for a long period of time.
CLICK HERE TO GO TO MAIN PAGE
CLICK HERE TO GO TO GOOGLE HOME PAGE