dark matter

123456789
Across
  1. 2. the nature of dark matter is _____.
  2. 3. dark matter does not emit light or ______
  3. 5. some countries dark matter _____ hidden deep under ground.
  4. 6. dark matter might not even ____.
  5. 8. dark matter is __________.
  6. 9. dark matter _____ galaxies together.
Down
  1. 1. Roughly 80% of the mass of the _________ is made up of material that scientists cannot directly observe.
  2. 3. scientist believe that dark matter is some sort of _____ particle.
  3. 4. dark matter is really ____ to study.
  4. 7. scientist have suggested many _______ about it.