The Sun is the largest and most important celestial feature in our solar system. Besides being the largest feature in the solar system, the Sun also contains approximately 98% of the solar system's total mass. Scientists estimate that the Sun had been active for 4.6 billion years and has enough fuel to go for another 5 billion years or so. When compared with the Earth, the Sun's size becomes even more impressive. It would require 198 Earth's in order to fit across the main disc, and the interior of the Sun could hold approximately 1.3 million planets the size of our Earth.
Dissecting the Sun
The outer most viable layer of the Sun is known as the photosphere and has a temperature of 6,000 degrees C (11,000 degrees F). This layer is characterized my its mottled appearance, which is caused by turbulent eruptions of the energy at the surface.
The raw power given off by the Sun is created deep within the core of the Sun which has a temperature of 15,000,000 degrees C (27,000,000 degrees F). The nuclear reactions that occur inside require an incredible amount of pressure in order to take place, about 340 billion times that of Earth at sea level.
What Process Occurs
Nuclear reactions power the Sun. This intense reaction causes four protons (hydrogen nuclei) to fuse together and form one alpha particle (helium nucleus).During this process energy is expelled, which would explain the .7 percent loss of mass. This energy is carried to the surface and released as light and heat through a process known as convection. It takes one million years for energy created in the Sun's ore to reach its surface. This process releases an unbelievable 5 million tons of pure energy and creates 700 million tons of helium ashes every second.
The layer right above the photosphere is called the chromosphere. Solar energy passes through this region on it way out from the center of the Sun. Faculae and flares occur in the chromosphere. Faculae are bright luminous hydrogen clouds which form above regions were sunspots are about to form. Flares on the other hand, are bright filaments of hot gas emerging from sunspot regions. Sunspots are dark depressions on the photosphere that typically has a temperature of 4,000 degrees C (7,000 degrees F).
The outer most region of the Sun is the corona. Prominences appear in this region.Prominences are immense clouds of glowing gas that erupt from the upper chromosphere. The corona region extends far into space and consists of many slow moving particles traveling away from the Sun. Only during a total eclipse can we see this region.
End of its Life
At the end of the Sun's life time it will begin to fuse helium into heavier elements causing it to swell up. It willultimately swell so large that it will consume the Earth. During this phase of its existence the sun is known as a red giant. A billion years later it will collapse into a white dwarf which is the final end product of a star like ours. It will take as much as a trillion years to completely cool off.