Return to Space Unit
(Pages 38-41 – Exp. Universe)
· The most important star to human life is our Sun. The Sun is at the center of our solar system.
· Life on the Earth begins with the Sun, and its energy. The Sun produces energy in the form of heat and light.
· In the center of the Sun, its core, nuclear fusion reactions change hydrogen into helium.
· These reactions release an unbelievable amount of energy.
· At the core, the Sun burns at a temperature of about 27 million degrees Celsius.
· The energy moves from the core to the surface (the corona) of the Sun, which has temperature of almost 2 million degrees Celsius.
· The energy then travels through space as electromagnetic waves of light.
· The Sun is much larger than the Earth, with a diameter of about 840,000 miles, compared to the earth’s diameter of about 8,000 miles. However, the Sun is only an average star.
Layers of the Sun:
· The sun has a core that has a temperature of 15,000,000°C
· It has three layers of atmosphere
o The Corona – is the outermost layer. (1,7000,000°C)
o The Chromosphere – The middle layer. (27,800°C)
o The Photosphere – The innermost layer of the sun’s atmosphere. (6,000°C)
· Prominences: violent storm that appears as an arch or loop. The chromosphere releases gases.
· Solar Flares: A storm that shows up as bursts of light. Increases the temperature of the sun to twice as hot!
· Solar Wind: A continuous stream of high energy particles released into space
· Sunspots: Dark areas on the sun’s surface. They are cooler than the rest of the surface