Across
- 2. An invisible line around which an object rotates
- 4. A moon, planet, or machine that orbits a planet of star
- 7. An object's orbital motion around another object
- 9. A luminous spheroid of plasma held together by its own gravity
- 11. An object's spinning motion around its own axis
- 13. A small rocky body orbiting the sun
- 14. A regular, repeating path that one object in space takes around another
- 15. A huge collection of gas, dust, and billions of stars and their solar system
Down
- 1. The daily changes in the level of the ocean water at any given place
- 3. A celestial body that is in orbit around a star and has a nearly round shape
- 5. The universal force of attraction acting between all matter
- 6. The four largest planets in our solar system, on the far side of the asteroid belt
- 8. Earth-like planets made of rocks or metals with a hard surface
- 10. One of two points inside an ellipse (oval) that determine the shape of its curve
- 12. The color of shift caused by the universe expanding