The Life cycle of the Sun

In our solar system, the sun is the largest star that we've ever discovered. Thought long ago to be a planet, the sun is actually a star. It contains 98% of our solar systems's mass and is by far the largest object known to exist in the Universe. The sun has an outer layer called the photosphere and it's temperature is 15,000,000 Celcius (27,000,000 F). That is 340 billion times more than the Earth's air pressure at sea level.

The intensity of the massive star causes and creates nuclear reactions.
Energy inside of the core of the Earth, takes a million years to reach the surface of the burning star. Everytime to sun releases its energy it becomes lighter, and this continues throughout years.

According to scientists, the sun has been around for more than 4.6 billion years and they claim it will have enough energy to go on for another five billion years.
After it's outlived its years, scientists claim that the sun will start swelling up and will finally grow so very large that it will swallow up Earth, as well as Mercury,Venus and Mars, the inner planets closest to it.It will become a red giant during this time.


A red giant is a star that has low surface temperature; which the sun will have when it gets to this stage of its life cycle.It will be a red giant for about 5 billion years and in this time, Mercury will be completely destroyed by it; and then suddenly the sun will collapse into a white dwarf star. This means that it will become a white star with high surface temperature and lower brightness. It will slowly become as small as the size of the Earth.


It will no longer have a fusion source of its own and will only have the heat that is leftover from its past days as a massive ball of heat. It will fade from it's brightness and darken and become cold. By this time Mercury is no more, no longer a planet in existance. And at the end of the sun's lifecycle, Mars, Venus and Earth will fall into a final, permanant orbit.


http://www-astronomy.mps.ohio-state.edu/~pogge/Lectures/vistas97.html

http://www.solarviews.com/eng/sun.htm