Across
- 1. space in which there is no matter
- 4. the act of increasing in size or volume or quantity of scope
- 6. a prediction based on existing evidence
- 7. how compact something is
- 9. the branch of astronomy dealing with the history and structure and dynamics of the universe
- 10. a collection of star systems
Down
- 2. a physicist who studies astronomy
- 3. the physical phenomenon of radiating energy in the form of waves or particles
- 5. emptiness
- 8. an increase in speed