2. Cosmic address The astronomical unit and the light year Dark matter and dark energy Atoms Matter Forces

3. Eclipses Motion of sun, moon, stars, and planets Changes in the sun, moon, stars, planets Axial tilt Seasons Ecliptic

4. Phases of the moon Retrograde motion Heliocentric model Kepler’s Laws Measuring the earth Eratosthenes

5. Newton’s Laws of Motion Inertia Gravitational force Weight Centripetal forces

6. Doppler Effect (red shift / blue shift) Atomic structure Electromagnetic waves Electromagnetic spectrum Filtering effects of the atmosphere Speed of light Refraction Atomic spectra

7. Resolving power Light-gathering power Telescope placement Advantages and disadvantages of different types of telescopes

8. Age, size, structure, and composition Layers Plate tectonics

9. Age, size, structure, and composition Origin Surface features (maria, regolith, craters) Orbit (lack of an) Atmosphere Distance Rotation Tides

10. Exoplanets Planet density Stars Planets Solar nebula theory Dwarf planets

11. Mercury Venus Earth Mars Features, size, structure, composition Similarities and differences

12. Jupiter Saturn Uranus Neptune Features, size, structure, composition Similarities and differences Moons

13. Comets Meteors vs. meteoroids vs. meteorites Composition and structure of comets and asteroids Kuiper Belt and Oort Cloud Evidence of impacts Specific asteroids Types of meteors