What is this?
This survey measures how dark your sky is using a simple star-counting technique called Naked-Eye Limiting Magnitude (NELM). Your observation joins a global database supporting long-term dark sky research.
By measuring how many stars you can see, scientists can track how light pollution changes over time — especially in designated Dark Sky areas.
No telescope needed. All you need are your eyes and a dark sky.
Before you start:
- • Wait for a clear night — preferably moonless and after astronomical twilight
- • Move away from direct light sources
- • Allow at least 20 minutes for your eyes to adapt to the dark
- • Avoid looking at bright screens — move inside to complete the survey
