I built Zenith: a live local-first fixed viewport planetarium

Zenith is a real-time planetarium web application that displays the stars directly above your location at approximately 180x magnification, making Earth's rotation visible as stars move across the screen. The project uses data from the Pan-STARRS telescope survey and calculates its field of view so that stars traverse the entire screen in 30 seconds, revealing the planet's rotation without time-lapse or acceleration. All location data remains local to the user's device and is never transmitted to the developer.