[smooc]

I'm pretty sure that the mechanical planetarium of Eize Eizinga from 1781 predates this "World's First". Maybe because it is projected?

It's worth your visit btw.

https://www.eisinga-planetarium.nl/en/history/

[sopchi]

One reproduces the sky as seen from Earth (planets, stars, galaxies, etc), while the other is a model of the solar system. The Zeiss device will let you see the sky as it is at different dates, from different places on Earth, will let you see the sky as if the Sun was not shining during daytime (so you can see the other objects). It is unfair to discount it as just a new way of presenting what that other machine was showing. They are in fact very different in what they can do.

[treve]

First thing I thought too! But I guess it's a different definition of planetarium.

Wikipedia has even older mentions of planetarium, but does cite the one in Franeker as the oldest still working: https://en.wikipedia.org/wiki/Planetarium

[_Microft]

This seems to be a model of the solar system which is more commonly known as „orrery“.

https://en.wikipedia.org/wiki/Orrery