Across
- 2. A collection of stars and their solar systems, gas and dust, all held together by gravity.
- 5. A luminous object consisting mostly of hydrogen and helium, held together by its own gravity.
- 9. A piece of rock or metal that falls from space into the Earth's atmosphere, where it burns and glows with heat.
- 11. The collection of eight planets, their moons, dwarf planets and other natural satellites that orbit around the Sun.
- 13. A curved path that an object takes around another object.
- 14. Everything that exists.
- 15. A force of attraction that pulls all things with mass toward one another.
Down
- 1. The time taken for the Earth to rotate once on its axis.
- 3. A scientist who studies space.
- 4. An object which orbits a planet.
- 6. The galaxy where our solar system is found.
- 7. The distance light travels in one year (in a vacuum).
- 8. The time for the Earth to make one complete orbit around the Sun.
- 10. an object that orbits a star, has sufficient mass to be round or nearly round, and has removed the debris and small objects from the area around its orbit.
- 12. An object that orbits a planet or asteroid.