comet vs spark

comet

noun
  • A celestial phenomenon with the appearance of such a body. 

  • A small Solar System body consisting mainly of volatile ice, dust and particles of rock whose very eccentric solar orbit periodically brings it close enough to the Sun that the ice vaporises to form an atmosphere, or coma, which may be blown by the solar wind to produce a visible tail. 

  • Any of several species of hummingbird found in the Andes. 

spark

noun
  • A small, shining body, or transient light; a sparkle. 

  • Any of various lycaenid butterflies of the Indomalayan genus Sinthusa. 

  • An electrician. 

  • A small amount of something, such as an idea or romantic affection, that has the potential to become something greater, just as a spark can start a fire. 

  • A small particle of glowing matter, either molten or on fire. 

  • A ship's radio operator. 

  • A short or small burst of electrical discharge. 

  • A gallant; a foppish young man. 

  • A beau, lover. 

verb
  • To shoot; to fire 

  • To trigger, kindle into activity (an argument, etc). 

  • To give off a spark or sparks. 

  • To light; to kindle. 

How often have the words comet and spark occurred in a corpus of books? (source: Google Ngram Viewer )