Across
- 3. Planetary orbit's eccentricity shape
- 6. Newton's law of universal gravitation's constant
- 8. Planetary motion's speed factor
- 10. Gravitational potential energy symbol
- 11. Gravitational potential energy unit
- 12. Spacecraft's gravitational assist maneuver
- 13. Kepler's laws describe
- 17. Energy due to position or height
- 18. Gravity's strength factor
- 19. Gravitational force's range
- 20. Gravitational force's effect on objects
Down
- 1. Newton's major work ("Philosophiæ _______")
- 2. Orbital path's closest point
- 4. Force responsible for planetary motion
- 5. Inverse square law's variable
- 7. Celestial body's attractive force
- 9. Orbital shape with foci
- 14. Astronomer who studied Mars' motion
- 15. Law of Universal Gravitation's publication year
- 16. Kepler's laws' key concept