PART I THE COSMIC LANDSCAPE<br>Unit 1 Our Planetary Neighborhood<br>Unit 2 Beyond the Solar System<br>Unit 3 Astronomical Numbers<br>Unit 4 Scientific Foundations of Astronomy<br>Unit 5 The Night Sky<br>Unit 6 The Year<br>Unit 7 The Time of Day<br>Unit 8 Lunar Cycles<br>Unit 9 Calendars<br>Unit 10 Geometry of the Moon, Earth, and Sun<br>Unit 11 Planets: The Wandering Stars<br>Unit 12 The Beginnings of Modern Astronomy<br>Unit 13 Observing the Sky<br><br><br>PART II PROBING MATTER, LIGHT, AND THEIR INTERACTIONS<br>Unit 14 Astronomical Motion: Inertia, Mass, and Force<br>Unit 15 Force, Acceleration, and Interaction<br>Unit 16 The Universal Law of Gravity<br>Unit 17 Measuring a Body's Mass Using Orbital Motion<br>Unit 18 Orbital and Escape Velocities<br>Unit 19 Tides<br>Unit 20 Conservation Laws<br>Unit 21 The Dual Nature of Light and Matter<br>Unit 22 The Electromagnetic Spectrum<br>Unit 23 Thermal Radiation<br>Unit 24 Identifying Atoms by Their Spectra<br>Unit 25 The Doppler Shift<br>Unit 26 Special Relativity<br>Unit 27 General Relativity<br>Unit 28 Detecting Light - An Overview<br>Unit 29 Collecting Light<br>Unit 30 Focusing Light<br>Unit 31 Telescope Resolution<br>Unit 32 The Earth's Atmosphere and Space Observatories<br>Unit 33 Amateur Astronomy<br><br><br>PART III THE SOLAR SYSTEM<br>Unit 34 The Structure of the Solar System<br>Unit 35 The Origin of the Solar System<br>Unit 36 Other Planetary Systems<br>Unit 37 The Earth as a Terrestrial Planet<br>Unit 38 Earth's Atmosphere and Hydrosphere<br>Unit 39 Our Moon<br>Unit 40 Mercury<br>Unit 41 Venus<br>Unit 42 Mars<br>Unit 43 AsteroidsUnit 44 Comparative Planetology<br>Unit 45 Jupiter and Saturn: Gas Giants<br>Unit 46 Uranus and Neptune: Ice Giants<br>Unit 47 Satellite Systems and Rings<br>Unit 48 Ice Worlds, Pluto, and Beyond<br>Unit 49 Comets<br>Unit 50 Impacts on Earth<br><br><br>PART IV STARS AND STELLAR EVOLUTION<br>Unit 51 The Sun, Our Star<br>Unit 52 The Sun's Source of Power<br>Unit 53 Solar Activity<br>Unit 54 Surveying the Stars<br>Unit 55 The Luminosities of Stars<br>Unit 56 The Temperatures and Compositions of Stars<br>Unit 57 The Masses of Orbiting Stars<br>Unit 58 The Sizes of Stars<br>Unit 59 The H-R Diagram<br>Unit 60 Overview of Stellar Evolution<br>Unit 61 Star Formation<br>Unit 62 Main-Sequence Stars<br>Unit 63 Giant Stars<br>Unit 64 Variable Stars<br>Unit 65 Mass Loss and Death of Low-Mass Stars<br>Unit 66 Exploding White Dwarfs<br>Unit 67 Old Age and Death of Massive Stars<br>Unit 68 Neutron Stars<br>Unit 69 Black Holes<br>Unit 70 Star Clusters<br><br><br>PART V GALAXIES AND THE UNIVERSE<br>Unit 71 Discovering the Milky Way<br>Unit 72 Stars of the Milky Way<br>Unit 73 Gas and Dust in the Milky Way<br>Unit 74 Mass and Motions in the Milky Way<br>Unit 75 A Universe of Galaxies<br>Unit 76 Types of Galaxies<br>Unit 77 Galaxy Clustering<br>Unit 78 Active Galactic Nuclei<br>Unit 79 Dark Matter<br>Unit 80 Cosmology<br>Unit 81 The Edges of the Universe<br>Unit 82 The Curvature and Expansion of Universes<br>Unit 83 The Beginnings of the Universe<br>Unit 84 Dark Energy and the Fate of the Universe<br>Unit 85 Astrobiology<br>Unit 86 The Search for Life Elsewhere<br><br><br><br><br>