Return to Space Unit

The Sun

(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)


Sun’s activity:

·        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