Planetarium (noun)

1. A building or room housing a device that projects images of stars, planets, and other celestial bodies onto a domed ceiling, used for educational and entertainment purposes.
2. A device for projecting images of the stars and planets.

Origin:

Late 19th century: from planet + -arium, on the model of observatory.

Examples:

1. She loved visiting the planetarium and seeing the stars projected on the ceiling.
2. The planetarium show was a big hit with the kids, who were fascinated by the images of the planets.
3. The school trip to the planetarium was a highlight of the year for many students.
4. The planetarium's projector was state-of-the-art and provided an incredibly realistic depiction of the night sky.
5. The children's section of the museum included a small planetarium where they could learn about the stars and planets.