Do extraterrestrial landscapes or planets count as nature? If I am talking about the surface of Mars, is this still nature, comparable to uninhabited places on earth, or does nature exclusively describe not man-made things on earth. 

I am asking this question in Astronomy, because I would like to know what astronomers or other people dealing with extraterrestrial science on a regular basis think about it.
ARTFL Nature: 


  
  The existing system of things; the world of matter, or of matter and mind; the creation; the universe.
  


That definition includes the surface of Mars, and the core of Betelgeuse.