Sun

	Diameter as seen from Earth	86,375 miles (1,390,000 km)
	Composition	hydrogen, helium
	Surface Temperature	9,940°F (5,505°C)
	Core Temperature	27,000,000°F (15,000,000°C)
	Period of Rotation	25 days at the equator, 36 days at the poles

Our Sun, named Sol, is at the center of our solar system, and even gives our planetary system its name.

The Sun is an ordinary star, one of about 100 billion in our galaxy, the Milky Way.

The Sun is about 4.5 billion years old, and will continue to put out heat and light for about 5 billion more years.

The Sun is made entirely of gasses, mainly hydrogen and helium, but it contains 99.8 percent of the mass of the entire solar system.

The Sun produces its energy through a process called fusion. The Sun's immense gravity squeezes it inside, creating so much heat that is actually fuses hydrogen atoms together, forming helium. This releases tremendous amounts of energy to the Sun's surface and out into space.

Links

For more information about Earth, its satellite, and our nearest star, see the Morehead Planetarium show Earth, Moon, and Sun and the many accompanying activities and links.

Activity Idea: visit www.solarviews.com/eng/edu/convect.htm and learn how to make a soup that illustrates heat convection, a process that occurs on the surface of the Sun. Convection functions because heated fluids, due to their lower density, rise and cooled fluids fall. A heated fluid will rise to the top of a column, radiate heat away and then fall to be re-heated, rise and so on. A high resolution image of the Sun shows a pattern that looks something like rice grains. Very large convection cells cause this granulation.