Changes

The sun is a type G2V star. By mass, it is composed of 72% hydrogen, 26% helium and 2% trace elements of oxygen, carbon, neon, nitrogen, magnesium, iron, and silicon.<ref>[http://www.nasa.gov/worldbook/sun_worldbook.html World Book Encyclopedia @ NASA]</ref>

The sun is a type G2V star; it is the star at the center of the solar system, and it accounts for over 99% of the mass of the solar system. By mass, it is composed of 72% hydrogen, 26% helium and 2% trace elements of oxygen, carbon, neon, nitrogen, magnesium, iron, and silicon.<ref>[http://www.nasa.gov/worldbook/sun_worldbook.html World Book Encyclopedia @ NASA]</ref> The eight planets, including Earth, orbit the sun, as do countless other small objects.

It provides the [[Earth]] with light and heat. In Christian theology, [[God]] created the sun on the first day of [[Creation]]. <ref>Genesis 1</ref>  

It provides the [[Earth]] with light and heat.

 

What eventually became the solar system initially existed as a large, rotating cloud of dust and gas, composed of hydrogen and helium produced in the Big Bang as well as small amounts of heavier elements. Around 4.57 billion years ago, the cloud began to contract, perhaps as a result of a shock wave from a nearby supernova. Inertia caused the rotating cloud to flatten into a disk. Most of the mass concentrated in the middle, and began to heat up. Eventually, the kinetic energy of the hydrogen was sufficient to overcome the electromagnetic repulsion between the protons, and fusion began. The resulting solar wind helped clear away much of the material which had not coalesced into planets or other orbiting bodies. <ref>[http://www.tufts.edu/as/wright_center/cosmic_evolution/docs/text/text_plan_1.html]</ref>. In Christian theology, [[God]] created the sun on the first day of [[Creation]]. <ref>Genesis 1</ref>  

 

 

 

 

==References==

==References==

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[[Category:Astronomy]]

[[Category:Astronomy]]