Bortle Scale ·
how dark is your sky?
un
seel
.com · 1 = pristine dark · 9 = inner city
Class 1
~4,500 stars
Class 9
fewer than 50
class
—
Class 1 · pristine dark
Class 4 · Milky Way fading
Class 7 · grey city wash
Class 9 · inner-city glow
Sliding marker
▶ Play
←
→
🔇 Unmute
Reset
Un
seel
.com · Bortle Scale