The sun is the star at the center of the solar system and is the source of light and heat for planets like Earth. The Sun is surrounded by eight satellites that we call planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Without the sun, we would not be where we are today. Our star is closest to our planet, so we can observe and study it and its solar phenomena such as sunspots, solar flares, solar winds and prominences. The sun is 1,390,000 kilometers in diameter and weighs approximately 1,989e30 kilograms. . At 5,800 degrees Kelvin, the sun is so hot that nothing can get close enough before being burned. The core of the sun is 2,700 times hotter than the surface, or 15,600,000 degrees Kelvin, and has a pressure of 250,000,000,000 atmospheres. It is composed primarily of hydrogen (70%) and helium (28%), with less than 2% metals, but these percentages change slowly over time as the Sun continually converts hydrogen to helium into its heart. several “layers”. The photosphere of the suns is the visible sun, that's what we see. It's one of the coldest regions on the sun, at just 6,000 degrees Kelvin. It is 500 kilometers deep and the convection of the suns brings energy to the photosphere. The chromosphere is only visible during an eclipse and looks like a thin pink line. For unknown reasons, the chromosphere is hotter than the photosphere and can vary from 6,273 degrees Kelvin to 20,273 degrees Kelvin. At these high temperatures, hydrogen emits a reddish color, clearly visible on a prominence. The chromosphere contains spicules, which are flame-shaped extensions of the chromosphere in the corona. The crown has a milky white glow during ...... middle of paper ...... the speed of light! The sun has many mysteries that we cannot yet explain but it is always fascinating to see how we rely so much on it and without it we would not be alive today. Works Cited NASA/Marshall Solar Physics. Internet. November 28, 2011. Seeds, Michael A. and Dana Backman. Foundations of astronomy. Brooks/Cole Pub Co, 2010. “Solar Flares” e-book. Internet. November 28, 2011. “Solar Flares, Prominences, Solar Wind, and Coronal Mass Ejections.” Enchanted learning. Internet. November 28, 2011. "Solar Phenomena: The Sun, Sunspots, and Current Sunspot Activity | Outer Space Universe." Outer Space Facts - Constellations Star Maps - Space Photos | Outer space universe. Internet. November 28, 2011. “Solar Prominence.” The universe today — News on space and astronomy. Internet. November 28, 2011. “Facts and pictures from The Sun L Sun. » Visiting the solar system of the nine planets. Internet. November 28. 2011.