BORTLE CLASS 6 / SKY KEY
Bright suburban sky
Skyglow dominates much of the view and faint galaxies and nebulae become substantially harder.
6
HOW TO READ IT
One number is a sketch of the sky, not the whole night.
A Bortle class describes what the sky looks like under particular conditions. Walk across a large park, turn toward a town, add snow or smoke, and the view can change. Use the number to compare darkness quickly, then read the stop page for the horizon, headlights, access and everything else that decides whether the place actually works.