Light pollution map
Find the darkest skies within driving distance. Search your town, then look for the black, gray and blue zones.
Click anywhere on the map for that spot’s sky brightness. Use the slider to compare years.
Open full screenThis map is the Light Pollution Atlas by David Lorenz, made from VIIRS satellite data and shown here from his site
What the Bortle scale means for astrophotography
The Bortle scale rates how dark the night sky is, from 1 (darkest) to 9 (inner city). The table gives a rough idea of what you can shoot at each level.
| Bortle | Sky | What you see | Good targets |
|---|---|---|---|
| 1-2 | Excellent dark site | Milky Way bright enough to cast shadows, zodiacal light easy to see | Everything, especially faint dust and galaxies |
| 3 | Rural | Milky Way full of detail, with some glow on the horizon | All broadband targets |
| 4 | Rural / suburban transition | Milky Way visible and faded near the horizon | Bright galaxies, clusters, all nebulae |
| 5-6 | Suburban | Milky Way faint or only overhead | Clusters, bright galaxies, and nebulae with a dual-band filter |
| 7-9 | City | No Milky Way, and the sky glows gray or orange | Emission nebulae with dual-band or narrowband, Moon and planets |
If your sky is bright, the filter guide lists targets that still work. The forecast shows which nights are clear and dark enough to be worth the drive
Dark sky questions
How do I find a dark sky site near me?
Search your town on the map, then look for the darkest colors (black, gray, blue or green) within driving distance. Zoom in to check for public land, a clear southern horizon and a safe place to park. State parks and certified dark-sky parks are often the best options.
What Bortle class do I need for astrophotography?
You can do astrophotography anywhere, as long as you pick targets that suit your sky. Bortle 1-3 skies are best for galaxies, the Milky Way and faint dust. In Bortle 5-9 suburbs and cities, try emission nebulae with a dual-band filter, star clusters, the Moon and the planets.