Before we begin to explore the earth’s layers from core to atmosphere and the materials that it is composed of, we will need to look at the earth’s early stages of formation. Included in this is will be; what materials the earth is comprised of, as well as; how they arrived on the earth, and the resulting heat energy that is inherent within our earth.
When the earth was still in its early stages of formation it was slowly accumulating mass from particles within the planetary rings that were attracted by the earth’s gravitational pull. These particles were metallic chunks; similar to iron meteorites, rocky chunks; similar to stony meteorites, and icy-gaseous chunks; similar to comets. As these particles collided with the earth it created stored heat energy through kinetic energy, we call this impact energy. With every impact the earth’s mass increased and the ...view middle of the document...
This causes the various materials to separate and enables them to flow further toward or away from the earth’s center according to their density. Once the various materials are flowing, they begin to layer according to their density. The more dense the materials, the closer to the center of the earth it will be while the less dense materials filter their way to the upper layers of the earth as they cool down.
As we begin to explore the earth’s layers from core to atmosphere we will start with the center of the earth and work outward. At the center of the earth is the inner core which is surrounded by the outer core. While both are comprised of dense iron; similar to iron meteorites, the inner core is solid and the outer core is liquid. Next is the mantle which is composed of dense rock; similar to stony meteorites, and has the asthenosphere and lithosphere within its composition. The asthenosphere is below the lithosphere and is weak, hot and mobile rocky material. The lithosphere is cold and ridged comprised of rocky material and is not only part of the mantle, but it includes all of earth’s crust as well. In addition to the lithosphere, the earth’s crust also contains the oceanic crust. Oceanic crust has a thin and dense basalt rock composition and the continental crust has a thick and less dense granite rock composition. Both the oceanic crust and the continental crust composition are similar to stony meteorites. Resting above the crust the earth has the hydrosphere, containing water, and above that is the earth’s atmosphere, containing various gases. Both the composition of the hydrosphere and the atmosphere are the result of the materials that would have been in the comets that collided with earth.
Through the examination of our earth’s history and composition we are able to recognize how the extraterrestrial materials that collided with the earth have contributed to the heat energy and materials that created the many layers that compose our earth based on the various densities.