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Energy the from Sun Living With a Star Sun Facts The Sun is rather ordinary when it comes to stars. In fact, there are 100 billion stars in our galaxy that are similar to the Sun. What makes our star unique is that it is ours—responsible for light, heat, and life as we know it. Learning Objectives Appreciate the scale of the Sun-Earth The sun emits a range of energies that make up the Electromagnetic EM spectrum. The range extends beyond the visible spectrum in both directions, beyond the red and beyond the violet. ROYGBIV The sun is a star that sheds a continuous flow of particles (solar wind) and electromagnetic radiation. and there’s more folks… The Sun’s outer atmosphere is called the corona. During solar storms, huge bursts of electromagnetic energy are emitted by solar flares Flares are sometimes accompanied by Coronal Mass Ejections (CMES) – eruptions of particles in the corona EM energies travel at the speed of light Some solar output is harmful Scale Model Demonstration What does the Earth get from the Sun that is essential to keep us alive? What evidence do you have that there is energy reaching you from the Sun? Focusing on Visible Light Photons Light is made up of bundles of energy called photons which travel through space. Each color of light is made of different photon energies. The energy level carried by violet light is about twice as much as red light. ROYGBIV Colors in Visible Light Electromagneti c energies travel at the speed of light Electromagnetic Low Energy Spectrum Very High Energy Particles from the Sun Particles travel at less than the speed of light Slower particles Faster Particles Photosphere The visible portion of the Sun. Random Walk For the Sun, a photon is generated at the center and makes its way to the surface. It may take up to a thousand years to get to the surface, and the form of the energy may change from Xray to visible wavelengths. When the photon leaves the Sun, it takes eight minutes to get to us at the speed of light. The 8-minute travel time to Earth by sunlight hides a thousandyear journey that actually began in the core. Sir Fredrick William Herschel In 1800, Sir Fredrick William Herschel split up sunlight using a glass prism instead of a diffraction grating. Herschel's experiment was important not only because it led to the discovery of infrared light, but also because it was the first time that someone showed that there were forms of light that we cannot see with our eyes. Infrared Video Clips Colors in Visible Light ROYGBIV Electromagnetic Electromagneti c energies travel at the speed of light Spectrum Infrared Low Energy Very High Energy Particles from the Sun Particles travel at less than the speed of light Slower particles Faster Particles CD ROM Play movie Infrared and Its Uses Ultraviolet or UV Right of the violet end of the spectrum. Invisible to humans Bees can see it Judging by where ultraviolet energy is located on this spectrum, do you think it has more or less energy than visible light? What have you heard about UV? Cause sunburn Damage our eyes Sunscreen and sunglasses block it Colors in Visible Light Electromagneti c energies travel at the speed of light ROYGBIV Electromagnetic Radio Waves Microwaves Infrared Low Energy Spectrum Ultraviolet Very High Energy Particles from the Sun Particles travel at less than the speed of light Slower particles Faster Particles CD ROM Looking at various wave lengths that make up the electromagnetic spectrum. Solar Wind Particle Coronal Mass Ejections CME Occasionally, a part of the Sun’s upper atmosphere (corona) erupts in a giant gust of solar storm particles called a Coronal Mass Ejection or CME Some CMEs are ejected outward from the Sun in the direction of Earth. CMEs often accompany solar flares. Colors in Visible Light Electromagneti c energies travel at the speed of light ROYGBIV Electromagnetic Radio Waves Microwaves Infrared Low Energy Spectrum Ultraviolet X-Rays Gamma Rays Very High Energy Particles from the Sun Particles travel at less than the speed of light Slower particles Faster Particles The Culprit in the Mystery Will CME, EM and solar wind knowledge help decide if the Sun caused the January disruptions in Earth? What happened to the Sun at 3:10 on 01/25? If the solar flare affected Earth in eight minutes, why did many of the mysterious events happen two days later, on 01/27? Do CMEs travel at the speed of light? Is the Sun always sending out both EM energy and solar wind? How fast does EM energy travel? How fast does solar wind travel? What happened on the Sun on 01/25? What happened on the Earth around 3:18? What happened on the Earth two days later? What do you think caused the events on 01/27? Knowing what you know now, do you think the solar flare and CME caused the mysterious events in Activity 1?