1. 22.3 Galaxies, Different Sizes and Shapes CLICK ME!!!

2. Main IdeaDetail Notes 1. The Milky Way is shaped like a disk with a bulge in the center. 1.Disk diameter is more than 100,000 light-years 1. The bulge is packed with stars about 26,000 light-years 1. Large faint layer of stars surrounds the disk and bulge 2. Because Earth is inside the disk, you have an edge- on view of the galaxy. 2. Appears as a band of blended star light 2. Named after its hazy appearance 2. Center is hidden by dust

3. Galaxies vary in appearance. The objects in the Milky Way move in the following ways: Stars and nebulae orbit the center and very high speeds Sun is so large it takes 250 million years to orbit

4. Three Major Types of Galaxies Spiral Elliptical Irregular

5. Old stars in the disk Younger stars in the arms Arms curve away from the center Disk shaped Spiral Galaxy Arms of stars, gas and dust Milky Way!

6. Elliptical Galaxy Made of mostly old stars Sphere or oval shaped Almost no dust or gas between stars Maffei 1 is an elliptical galaxy in the constellation Cassiopeia. It is the closest giant elliptical galaxy to the Milky Way NGC 1427A, an example of an irregular galaxy. Irregular Galaxy Very faint or hard to see galaxies They have no definite shape Smallest type of galaxy Fewest stars