2.  Within the sun, nuclear reactions produce an immense amount of energy that streams outward into space as electromagnetic radiation.

3.  The sun produces the full range of electromagnetic radiation in what is known as the electromagnetic spectrum.

4.  Most of the sun’s radiation travels outward as three types of waves: infrared (IR) radiation, visible light, and ultraviolet (UV) radiation.  These waves travel through space at the same speed but are distinguished from one another by their wavelength.

5.  Of the three types of waves, infrared and visible light waves make up the majority of the radiation that reaches Earth.  Although your eyes cannot detect IR radiation, you can feel it. That’s because your skin absorbs infrared radiation and heats up. Infrared = heat.

6.  The visible portion of the sun’s electromagnetic spectrum contains the colors of light that your eyes can detect.  The third type of radiation, ultraviolet (UV) radiation, like infrared radiation, cannot be detected by your eyes. UV radiation can have harmful effects on living tissue. Fortunately, the ozone layer in Earth’s atmosphere filters out most of this harmful radiation before it reaches the ground.