Chapter 26 The Sun and the Solar System

Chapter 26: The Sun and the Solar System Ø 26. 1: The Sun’s Size, Heat, and Structure Ø 26. 2: Observing the Solar System 1

26. 1: The Sun’s Size, Heat, & Structure A. The Sun's Energy 1. Diameter of the sun is 1, 400, 000 km. 2. A million Earths could fit inside the sun. 3. Fusion-the combining of the nuclei of lighter elements to form a heavier element. 2

26. 1: The Sun’s Size, Heat, & Structure 4. Why do hydrogen and helium exist as plasma? Because of intense heat and Pressure 5. Plasma-Fourth state of matter consisting of charged particlesthe nuclei, or ions, which have a positive electric charge, and electrons, which have a negative charge. 6. What happens to the mass? It is converted into energy 3

26. 1: The Sun’s Size, Heat, & Structure B. The Sun's Layers (p. 573) 1. Core-composed of hydrogen and helium in a plasma form, which is 100 times denser than water. Has a temperature of 15, 600, 000ºC. 2. Photosphere-The visible surface of the sun. Has a temperature of 6, 000ºC. 4

26. 1: The Sun’s Size, Heat, and Structure 3. Chromosphere-Inner layer of the Sun's atmosphere. Extends a 1000 km above the Photosphere. It has a temperature of 20, 000ºC, which causes hydrogen to emit a reddish color. 4. Solar Prominence- Dense clouds of material suspended above the sun's surface by magnetic fields. They can erupt for a few minutes or several hours, extending 1000 s of km into space. 5

26. 1: The Sun’s Size, Heat, and Structure 5. Corona-Thin outer atmosphere, which is a million times less bright than the photosphere. Has a temperature ranging from 1, 000ºC - 3, 000ºC. 6

26. 1: The Sun’s Size, Heat, & Structure C. Features of the Sun 1. Sunspots-Dark spots on the photosphere. Range in size and duration. 2. Magnetic field is 1000 x stronger than the surrounding photosphere and has an 11 year cycle. 3. Solar Wind- a constant stream of electrically charged particles from the corona. 7

26. 1: The Sun’s Size, Heat, & Structure C. Features of the Sun 4. Solar Flare- outbursts of light that rise up suddenly in areas of sunspot activity. 5. Particles from solar wind interact with Earth's magnetic field, causing auroras. 6. What is a side effect of solar wind? Auroras 8

26. 2: Observing the Solar System A. The movements of Planets and Stars 1. What does geocentric mean? Earth Centered 2. What are the wandering points of light? Stars 3. What is the backward motion of planets called? Retrograde 9

26. 2: Observing the Solar System B. Ptolemy's Geocentric Model 1. Developed the first model to locate planets. 2. Proposed that planets traveled in epicycles. 10

26. 2: Observing the Solar System C. Copernicus's Heliocentric Model 1. What does the heliocentric model say? The Sun is at the center of our Solar System 2. What causes retrograde motion? Different Speeds of Planetary Revolution 11

26. 2: Observing the Solar System D. Tycho Brahe, Johannes Kepler, and Planetary Motion 1. Brahe studied the planets individually. Most of his observations were made before the invention of the telescope. 2. Kepler continued his work & discovered the orbits were elliptical. 3. Kepler had three planetary laws. What were they? 1. Planets travel in elliptical orbits with the sun at the center 2. Equal Area Law 3. Harmonic Law 12

26. 2: Observing the Solar System E. Isaac Newton & the Law of Gravitation 1. What is inertia? An object in Motion Remains in Motion until acted upon by an outside force… 2. What is the big G force? GRAVITY 13