Puzzle 51

1234567891011121314151617181920
Across
  1. 4. Rich in sound
  2. 5. Unpredictable or impulsive
  3. 8. Fear of strangers
  4. 9. Sudden realization
  5. 12. Interstellar cloud
  6. 13. Term for Astrological signs
  7. 15. Sweetly flowing
  8. 17. Pleasure from misfortune of others
  9. 18. Short-lived
  10. 19. Sacred Indian river
  11. 20. Place side by side
Down
  1. 1. Mystery or puzzle
  2. 2. Distant of cosmic object
  3. 3. Persistence or determination
  4. 6. Illusion or apparition
  5. 7. Combine elements into something
  6. 10. Model or example
  7. 11. Emitting light due to high temperature
  8. 14. A pleasant surprise
  9. 16. Capital city of Kazakhstan