This is the 4086th most frequent Japanese word.
プラネタリウム
Planetarium.
In this sentence, 'プラネタリウム' is used as a noun referring to a physical location or facility where celestial projections are shown.
昨日、家族みんなでプラネタリウムに行きました。
Yesterday, my entire family went to the planetarium.
Here, 'プラネタリウム' is used to describe the venue where the observation of the starry sky happened.
プラネタリウムで見た星空はとても美しかったです。
The starry sky seen at the planetarium was very beautiful.
In this sentence, 'プラネタリウム' indicates specialized equipment or apparatus used for celestial displays.