section_path: Related fields/Planetary science
section_name: Planetary science
paragraph_text: Planetary science
  
  While the discipline of geography is normally concerned with the Earth, the term can also be informally used to describe the study of other worlds, such as the planets of the Solar System and even beyond. The study of systems larger than the Earth itself usually forms part of Astronomy or Cosmology. The study of other planets is usually called planetary science. Alternative terms such as areography (geography of Mars) have been employed to describe the study of other celestial objects. Ultimately, geography may be considered a subdiscipline within planetary science.