The universe

12345678
Across
  1. 3. an orbital disc consisting of gas, stars, and planets.
  2. 6. a star with its orbiting planets and objects.
  3. 7. an area with virtually no mass.
  4. 8. contains all stars, galaxies, and black holes.
Down
  1. 1. a large group of galaxies.
  2. 2. a group of galaxies.
  3. 4. an object that orbits a star without sharing its orbit.
  4. 5. an object that permanently orbits a planet.