Planetarium -

: Often called a "star projector" or "starball," these devices (like the famous Zeiss models) project high-resolution images of stars and planets onto the dome.

: Modern venues, such as the James S. McDonnell Planetarium , combine traditional mechanical projectors with digital systems for full-dome data visualization. Building Your Own (DIY) Planetarium

: Modern domes are often made of perforated aluminum sheets. These millions of tiny holes allow for proper air ventilation and prevent sound from echoing, ensuring an immersive audio-visual experience. : Often called a "star projector" or "starball,"

My Little Planetarium : 8 Steps (with Pictures) - Instructables Planetarium