Chapter 8, Astronomy Lesson 5, Galaxies and Beyond Objectives __________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Main Idea __________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Vocabulary galaxy ______________________________________________________________ _______________________________________________________________ Milky Way __________________________________________________________ _______________________________________________________________ spectrum ___________________________________________________________ _______________________________________________________________ expansion redshift ____________________________________________________ _______________________________________________________________ big bang ____________________________________________________________ _______________________________________________________________ background radiation _________________________________________________ _______________________________________________________________ What are galaxies? Is a constellation a natural grouping of stars? ______________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ In what way are stars naturally grouped? _________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ The Milky Way Galaxy What is the name of the galaxy in which Earth is located? What type of galaxy is it? _________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ How can you tell that Earth is in one of the Milky Way’s spiral arms and not in its center? _____________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Quick Check Fact and Opinion “The Milky Way is a spiral galaxy.” Is this statement a fact or an opinion? Why? __ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Critical Thinking How are the three types of galaxies similar? How are they different? __________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ What was the big bang? If all of the galaxies are moving away from one another, how would their positions now compare with their positions in a hundred years? _______________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ How would their positions a hundred years ago compare with their positions now? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ What about a thousand years ago? ______________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ As you look further and further back in time, what do you see happening to the universe? ___________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Can we see everything there is? _________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Formation of the Solar System Read a Diagram Star Formation How does this region of galaxy M33 resemble “starburst” galaxies? ____________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Quick Check Fact and Opinion “Scientists theorize that the universe was very hot and dense in its first moments.” Is this a fact or opinion? Why? _________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Critical Thinking What do astronomers think caused the background radiation found in space? ____ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ How did Earth form? Of what are the inner planets mostly made? Of what are the outer planets mostly made? _____________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ What keeps the rock in the planets and the gas in the Sun from flying out into space? _____________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ What formed the atmosphere that surrounds Earth today? ___________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Read a Diagram How Our Solar System Formed What part did gravity play in the formation of the solar system? _______________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Quick Check Fact and Opinion “Plants did not exist on Earth in its first years, because the atmosphere lacked oxygen.” Is this statement a fact or an opinion? Why? ______________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Critical Thinking How did Earth’s original atmosphere evolve into its present one? ______________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________