Code review comment for lp:~georg-zotti/stellarium/gz_fix-ecliptic-obliquity

> >"Ecliptic" is only Earth's orbital plane, there is no source or reason for
> confusion. But given the fact that we also don't show ecliptical grid of date
> if located on other planets, I will change to not show it if location is not
> on Earth.
>
> Why? When we say "ecliptic" then we saying about Earth, it's typical, but
> other planets has "path of the Sun" too and other planet has ecliptic too ;)

No, "The Ecliptic" is specifically the projection of Earth's instantaneous orbital plane onto the celestial sphere, appearing as great circle.

Other planets' orbital planes are just called "orbital planes", and Stellarium so far never made an attempt to show other planets' orbital planes (although it would certainly be nice for astronaut training...). "Ecliptic" is particularly Earth-related, like "The Moon" is only our Earth's moon.

There is apparently some widespread idea that Earth's orbital plane is stable in VSOP coordinates. It is not the case, as we can see here and now! VSOP has the J2000.0 ecliptical plane as their XY-plane, which Stellarium can show as "Ecliptic of J2000.0". But Earth's orbit is wandering around a bit, which is called the Precession of the Ecliptic (Earlier name: "planetary precession", but in the post-2000 literature authors preferred "Precession of the Ecliptic").