asteroid vs celestial object

asteroid

noun
  • In the Solar system, such a body that orbits within the orbit of Jupiter 

  • Any member of the taxonomic class Asteroidea; a starfish 

  • A naturally occurring solid object, which is smaller than a planet, larger than a meteoroid and not a comet, that orbits a star and often has an irregular shape. 

celestial object

noun
  • Synonym of celestial body. 

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