Across
- 1. the amount of matter something has
- 4. loose collection of atoms
- 7. interacts only via the weak interaction and gravity
- 8. smallest unit of a substance that still acts like the main substance
- 10. pulls matter together
- 11. cloud of dust or gas
- 12. bright ball of gas
- 14. last name of astronomer who found dark matter
- 16. about 100 billion stars
- 18. defined as matter composed of the antiparticles
- 19. where light and matter can not escape if they fall in
Down
- 2. an explosion of a star
- 3. unknown form of energy
- 5. tiny amount or small piece of something
- 6. hypothetical particles that are one of the proposed candidates for dark matter.
- 9. approximately 27% of the matter in universe
- 10. set of particles theorised to explain the dark matter in our universe
- 13. discovered evidence for missing mass in galaxies
- 15. makes up a vast amount of galaxies
- 17. hypothetical particle that appears in extensions of the Standard Model