It appears the term cislunar specifically refers to the space between Earth and the Moon's orbit.

Is there a generic term to describe the space between any planet and the orbits of its natural satellites, or between any body and its satellites? For example, one that could equally describe the space between Mars and Deimos (thus including Phobos' orbit), or the space within the Jovian system, or indeed the Earth/Moon system?

Or can cislunar be used in this way? I tried looking for it but it doesn't seem to appear much in other contexts.

  • 1
    This question is more suitable for Astronomy.
    – Mick
    Jan 18, 2018 at 22:18
  • Welcome to EL&U. As Mick notes, while questions about specialized terminology are not explicitly off-topic here, you would likely receive more and more-informed answers if you direct them to subject matter experts. See e.g. Is “interlunar” applicable to the moons of other planets? The prefix cis- means this side of, as in cisalpine Gaul, from which you could coin a term like cisganymedian or cistitanean but such terms don't appear to be in actual use, and I would anyway suggest sublunar to cislunar as a more accessible synonym.
    – choster
    Jan 18, 2018 at 23:08
  • Cislunar is an established term that is being quite heavily used in the media e.g. popularmechanics.com/space/a25872/nasa-cis-lunar-orbit but it is specific to earthlings looking up at their own moon in its use of the prefix cis. I cannot find any term used of other planetary bodies but @choster 's suggestion of sublunar seems a good one.
    – Nigel J
    Jan 18, 2018 at 23:52
  • Astronomy related sources use the term cismartian for the space near Mars. There hasn't been much need to use terms for the space near other planetary bodies, let alone the space between other planetary bodies and their moons but you can easily coin the term with cis- prefix + astronomical body adjective. Astronomers use "cis- + planetary adjective" for now.
    – ermanen
    Jan 19, 2018 at 3:25
  • Thanks for the helpful responses! I will be sure to direct technical questions to more specific spaces in the future then, but I've already learned new things from you folks.
    – GarrickW
    Jan 19, 2018 at 18:02

1 Answer 1


Cislunar is coined from Luna (Latin for Moon). So it only refers to our moon. However if you were to be on Mars and would refer to the space between Deimos and Mars, you could very well say “cisdeimian” space.

The same could be applied to other moons that have a name. As of now this is still science-fiction, so you are not limited with accepted terminology.

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