Where are is the ISS?
I have always wanted to buy a smart-telescope and have it track objects in the night sky. While I can't afford one of those right now, I wanted to see if there was any data available publicly that I could play around with. Ofcourse, I started by asking Gemini and it helped me visualize this problem. This was also around a time when I was planning to go stargazing so I deployed it on Github Pages so I could check it on my phone and quickly get a direction and elevation reading - but my friends liked it too so I have kept it on there and also added other objects it can track (more coming soon).
When you open the page, the app immediately asks for your location. With that, it:
- Pulls in the TLE data of satellites (ISS, Tiangong, Hubble, NOAA-19, Starlink, and GPS).
- Propagates their orbits forward minute-by-minute using satellite.js.
- Filters out the passes where the satellite is below 10° elevation, not sunlit, or not visible from the observer’s dark sky.
- Displays the passes in a card layout: date, time, max elevation, where it appears/disappears, and how long it’s visible.
I added some subtle UI touches too like a violet hover glow on pass cards, a custom dropdown icon for satellite selection, and a dark theme to keep the vibe astronomy-night friendly.