All Night Sky

All Night Sky is an interactive planetarium for the browser. Point it at a date, time, and place, and it renders the sky exactly as it appears overhead — a real-time sky map with constellation overlays, plus planet and star identification you can tap to learn more. I built it to make stargazing approachable without installing anything.

Under the hood it uses WebGL for smooth panning and zooming across thousands of objects, and standard astronomical algorithms to compute accurate positions for the Sun, Moon, planets, and stars. A time-travel control lets you wind the sky forward or back to line up a conjunction, an eclipse, or last night’s view.

It’s a progressive web app, so it installs to a phone and works well out in the field.