planetarium

As nouns the difference between planetarium and planetary

is that planetarium is planetarium while planetary is a planetary nebula.

As an adjective planetary is

(astronomy) of, or relating to planets, or the orbital motion of planets.

As nouns the difference between planetarium and constellation

is that planetarium is a display museum in which images of stars and other astronomical phenomena are projected onto a domed ceiling while constellation is an arbitrary formation of stars perceived as a figure or pattern.

As nouns the difference between planetarium and observatory

is that planetarium is a display museum in which images of stars and other astronomical phenomena are projected onto a domed ceiling while observatory is a place where stars, planets and other celestial bodies are observed, usually through a telescope.

As nouns the difference between planetarium and building

is that planetarium is a display museum in which images of stars and other astronomical phenomena are projected onto a domed ceiling while building is the act or process of building.

As a verb building is

present participle of lang=en.

As nouns the difference between planetarium and planetarian

is that planetarium is a display museum in which images of stars and other astronomical phenomena are projected onto a domed ceiling while planetarian is astrologer.