Translation guide
A planetarium is a building or room with a domed ceiling where images of stars, planets, and other celestial objects are projected, often for educational or entertainment purposes. In Japanese, the most common word is プラネタリウム, a loanword from English. There is also a native term 天象儀, but it is more technical and less frequently used in everyday conversation.
Referring to the building, room, or the show itself where stars and planets are projected onto a dome.
プラネタリウム is a loanword and is used just like the English word. You can say プラネタリウムに行く (go to the planetarium) or プラネタリウムを見る (watch a planetarium show). It is perfectly natural in both casual and formal contexts.
When I was a child, I often went to see planetarium shows.
The standard, everyday word for a planetarium. Used for both the facility and the show. This is a loanword from English and is widely understood.
Would you like to go to the planetarium this weekend?
The projection at this planetarium is very beautiful.
A native Japanese word for a planetarium projector or the instrument itself. It is technical and rarely used in daily conversation. Most people would use プラネタリウム instead.
An old planetarium projector is on display at this museum.