celestial body vs major planet

celestial body

noun
  • A natural object which is located outside of Earth's atmosphere, such as a comet, an asteroid, the Moon, a planet, the Sun, or a star. 

major planet

noun
  • Any of the 8 celestial bodies which orbit the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune (a celestial body that fits the 2006 IAU definition of planet). 

  • Any planet that is significantly larger and more massive than Earth, containing large amounts of hydrogen and helium, such as Jupiter and Neptune. 

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