Related Clues:

• Spiral ___
• Theme of this puzzle
• Astronomer's sighting
• Hale-Bopp, e.g.
• Interstellar cloud
• Kitchen cleanser
• Doomsday cause, maybe
• Common cleanser
• Streaker in the night sky
• Celestial object
• Bill Haley bandmate
• Heavenly body with a tail
• Rival of Ajax
• Heavenly body
• Crab ___