earthbound vs subsolar

earthbound

adj
  • Heading towards Earth. 

  • Unimaginative or mundane. 

  • Confined to the Earth; unable to leave Earth, either physically or spiritually. 

subsolar

adj
  • directly beneath the sun 

  • between the tropics; equatorial 

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