Light pollution map
Light pollution worldwide: tap the map to get the Bortle class, sky brightness and limiting magnitude at any point.
How to use this map
The Bortle scale rates sky darkness from 1 (a perfectly dark sky) to 9 (inner city). SQM is sky brightness in magnitudes per square arcsecond: the higher the number, the darker the sky. NELM is the naked-eye limiting magnitude.
Driving 20–30 km out of town is often enough to get from a red zone into a green one. The AstroTools app carries this map with you and pairs it with the astro-weather forecast and night score.
Plan your observing with AstroTools
Weather, the Moon, light pollution and satellite passes — in one app.