What is Solar Energy?

Solar Energy - Energy received by the Earth from the sun in the form of radiation. Each form of energy is differentiated by its wavelength.

Vocabulary

VocabularyElectromagnetic SpectrumConsists of the complete range of wavelengths of electromagnetic waves.

Take notes on the following:

- At what speed does radiation travel through space?

- Illustrate the wavelength of a wave?

- Figure 1: This is five images of the at different .

Read page 555

http://sohowww.nascom.nasa.gov/data/realtime/soho/soho_fader.html

7

Looking at the Sun in visible

light reveals dark spots on its

surface.

The Visible Sun

8

In this specific color of red light we can see more

details of the Sun’s magnetic

activity.

The Sun in H-alpha

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From space, we can observe the Sun in ultraviolet

(UV) light and see hot gas trapped in

magnetic fields on the Sun.

The Ultraviolet Sun

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The Dynamic Sun

The corona is known to be very hot because it has ions with many electrons removed from the atoms.

At high enough temperatures the atoms collide with each other with such energy to eject electrons. This process is called ionization.

At very high temperatures, atoms like iron can have 9 to 13 electrons ejected. Nine-times ionized iron is only produced at temperatures of 1.3 million K and 13-times ionized iron means the temperature gets up to 2.3 million K! During strong solar activity, the temperature can reach 3.6 million K and lines from 14-times ionized calcium are seen.

http://d43fweuh3sg51.cloudfront.net/media/assets/wgbh/phy03/phy03_img_lpaemspect/phy03_img_lpaemspect.jpg

E=mc2

Speed of light (c) = 3.0 x 107 m/s