2. Types of Galaxies Spirals (77%) Ellipticals (20%) Irregulars (3%) National Optical Astronomy Observatory images

3. a: NASA/Hubble Space Institute; b: Robert Gendler; c: Anglo- Australian Observatory

11. (a)NASA; (b) Royal Observatory, Edinburgh

12. a: J. D. Wray, McDonald Observatory; b, c: 1999 Princeton University Press/Zsolt Frei and James E. Gunn

17. Closer Galaxies move away from us Farther Galaxies move away from us faster

18. Hubble’s Constant Tells Age: H 0 = Velocity/Distance = 1 / Time Hubble’s Law: Velocity = H 0 x Distance