Monthly Archives: September 2010

Our Planet Earth

Planet Earth-Our Planet.
Looks like a tiny blue dot from outer space. Our planet was formed approximately 4.5 billion years ago.

Structural Composition
Earth is made up of layers of rock, usually a mixture of various minerals.  The outer layer of Earth, known as the crust, consisting of low-density silicates. The crust is thin on ocean floor and thick under continents. After Crust, follows mantle,consisting of dense silicates. And Lastly comes Core, which is further divided into inner core and outer core.Between the crust and mantle, there is another layer known as lithosphere, a hard layer of rock composed of crust and partly mantle.
On the Outside
Biosphere or the layer of living organisms and life existed on earth approximately 3.5 billion years ago.
Earth’s Surface
Earth’s surface is formed via geological processes viz, impact craters,volcanoes,tectonic shift, and erosion.