Across
- 1. The angle between the planet's rotational axis and its orbital axis
- 5. Intermediate phase of the Moon
- 6. the trajectory of a planet around a star
- 9. A regular, repeating path that one object in space takes around another one
- 14. Composed mainly of hydrogen and helium
- 17. Having or representing the sun as the center
- 19. The use of astronomy and space technology
- 20. A symbol or emblem used to represent the lunar phase in the first quarter
- 22. Earth's only natural satellite
- 23. The dark, inner shadow of planet Earth
- 24. Appears fully illuminated from Earth's perspective
- 26. The number of occurrences of a repeating event per unit of time
- 28. Collection of eight planets and their moons in orbit
- 29. The universal force of attraction acting between all matter
- 30. The side of the moon not visible from earth
Down
- 2. Highest level
- 3. A naturally occurring physical entity
- 4. A small planetary-mass object that is in direct orbit of the Sun
- 7. The throwing back by a body or surface of light
- 8. Gravity and inertia act in opposition on the Earth's oceans
- 10. The four innermost planets in the solar system
- 11. Occurs three or four times per year
- 12. Partial obscuring of a celestial body by another
- 13. The star at the center of the Solar System
- 15. Where strong magnetic fields bind plasma
- 16. A small rocky body orbiting the sun
- 18. Representing the earth as the center
- 21. The lighted area around the shadow of a planet or moon during an eclipse.
- 25. The side of the moon visible from earth
- 27. Lowest level