# Light Pollution Map

> Interactive global light pollution map for Bortle Scale, SQM, dark-sky planning, Milky Way visibility, aurora viewing, weather context, and astrophotography exposure decisions.

Light Pollution Map helps astronomers, astrophotographers, travelers, educators, and dark-sky advocates compare night-sky brightness around the world. The web app combines a map interface with sky quality readings, historical light pollution layers, certified Dark Sky Places, aurora probability, moon phase information, weather context, and planning tools.

## Primary URLs

- Web app: https://lightpollutionmap.app/
- AI overview: https://lightpollutionmap.app/llms.txt
- Full AI reference: https://lightpollutionmap.app/llms-full.txt
- Structured knowledge JSON: https://lightpollutionmap.app/knowledge/site.json
- Global light pollution rankings: https://lightpollutionmap.app/global-light-pollution-rankings/
- Markdown version of rankings: https://lightpollutionmap.app/global-light-pollution-rankings.md
- Chinese site: https://www.darkmap.cn/

## What The Site Is For

- Finding darker places for stargazing and Milky Way viewing.
- Comparing Bortle class and SQM values for locations.
- Checking light pollution trends from annual VIIRS-derived data.
- Planning astrophotography exposure under different sky brightness levels.
- Combining light pollution with weather, lunar phase, and aurora context.
- Sharing or embedding a specific map view.

## Key Concepts

- Bortle Scale: a public-friendly class from 1 to 9 for night-sky quality.
- SQM: sky brightness in magnitudes per square arcsecond.
- Artificial brightness ratio: sky brightness compared with natural background.
- Dark Sky Places: certified areas with protected night environments.
- Aurora probability: NOAA-based forecast layer for northern lights planning.

## Data Sources And Limits

The map is generated by LightPollutionMap.app from NOAA VIIRS annual night-light data using a sky-brightness modelling pipeline. Bortle class is a simplified reference for quick interpretation; SQM and all-sky skyglow views are better for comparing actual observing conditions. Weather, aurora, and moon data should be used as planning signals, not as guarantees of visibility.

## Related App

Stargazing Hub is the companion mobile observing toolkit for iOS and iPadOS:

- App Store: https://apps.apple.com/cn/app/id1478601599
- Website: https://stargazinghub.com/

Light Pollution Map does not publish invented reviews. App rating metadata is derived from the public Apple iTunes Lookup response for Stargazing Hub, using the China mainland App Store region first because it has the higher rating count, with the United States region as fallback.