Across
- 7. having or representing the sun as the center
- 8. a system of millions or billions of stars, together with gas and dust,
- 10. having or representing the earth as the center
- 12. hydrogen and helium, such as Jupiter, Saturn, Uranus, or Neptune
- 13. Planet Earth-like planets made up of rocks or metals with a hard
- 14. a celestial body moving in an elliptical orbit around a star.
- 16. all existing matter and space considered as a whole
- 18. together by gravitational attraction.
- 19. high density and temperature.
- 20. Planet a celestial body resembling a small planet but lacking certain
Down
- 1. Way the galaxy in which we live that contains the stars that make up
- 2. Milky Way.
- 3. and comets
- 4. criteria that are required for it to be classed as such.
- 5. the sun, a tail of gas and dust particles pointing away from the sun.
- 6. Bang theory that describes how the universe expanded from an initial state
- 9. small rocky objects that orbit the Sun.
- 10. giants a large planet of relatively low density consisting predominantly
- 11. a celestial object consisting of a nucleus of ice and dust and, when
- 15. the sun, together with smaller bodies in the form of asteroids,
- 17. System the collection of eight planets and their moons in orbit