1. Prologue Scale of the Universe

2. Figure P.1a The Constellation Orion

3. Figure P.1b The Constellation Orion

4. Figure P.2 The Celestial Sphere

5. Figure P.3 The Northern Sky

6. Figure P.4 Right Ascension and Declination

7. Figure P.5 Solar and Sidereal Days

8. Figure P.6 The Zodiac

9. Figure P.7 Ecliptic

10. Figure P.8 Seasons

11. Figure P.9 Precession

12. More Precisely P-1 Angular Measure

13. Figure P.10 Triangulation

14. Figure P.11 Parallax

15. Figure P.12 Parallax Geometry

16. More Precisely P-2a Measuring Distances with Geometry

17. More Precisely P-2b Measuring Distances with Geometry

18. Discovery P-1 Sizing Up Planet Earth