# Light Pollution Map

> Light Pollution Map is an interactive web application that displays global light pollution data using the Bortle Scale and SQM measurements, helping users find optimal locations for stargazing, Milky Way viewing, and aurora observation.

## Overview

Light Pollution Map (lightpollutionmap.app) provides a comprehensive, interactive visualization of global light pollution data. The map utilizes the Bortle Scale and Sky Quality Meter (SQM) measurements to help astronomy enthusiasts, photographers, and nature lovers identify optimal locations for stargazing and astrophotography.

The application combines satellite data from NOAA's VIIRS with user-friendly map interfaces to display light pollution levels worldwide. Users can search for specific locations, obtain detailed information about night sky quality, and plan their stargazing activities accordingly.

## Key Features

### Interactive Map Interface

The core of the application is an interactive map that displays light pollution data using color-coded overlays. Users can:

- Pan and zoom to explore different regions
- Toggle between different base maps (Dark, Satellite, Streets)
- Adjust the opacity of the light pollution overlay
- Search for specific locations using the built-in geocoder
- View historical light pollution data from 2006 to 2024
- Toggle day/night terminator to see which parts of the world are currently dark
- View certified Dark Sky Places worldwide

### Bortle Scale Integration

The Bortle Scale is a nine-level numeric scale that measures the night sky's brightness of a particular location. The scale ranges from Class 1 (excellent dark-sky sites) to Class 9 (inner-city skies). On our map:

- Class 1-2 (Dark blue): Excellent dark skies with minimal light pollution
- Class 3-4 (Green): Rural to rural/suburban transition areas
- Class 5-6 (Yellow): Suburban skies
- Class 7-9 (Red/White): Urban/city skies with significant light pollution

### Location Details

When users click on a specific location, the application provides detailed information:

- Precise latitude and longitude coordinates
- Bortle Scale classification for the selected point
- SQM (Sky Quality Meter) value in magnitude per square arcsecond
- Milky Way visibility assessment
- Estimated number of visible stars
- Historical light pollution data (2006-2024) with trend visualization
- Information about certified Dark Sky Places (if applicable)

### Multi-language Support

The website is available in multiple languages:
- English (default): https://lightpollutionmap.app/
- Spanish (Español): https://lightpollutionmap.app/es/
- Japanese (日本語): https://lightpollutionmap.app/ja/
- Polish (Polski): https://lightpollutionmap.app/pl/
- German (Deutsch): https://lightpollutionmap.app/de/
- Italian (Italiano): https://lightpollutionmap.app/it/
- French (Français): https://lightpollutionmap.app/fr/
- Norwegian (Norsk): https://lightpollutionmap.app/nb/
- Russian (Русский): https://lightpollutionmap.app/ru/
- Turkish (Türkçe): https://lightpollutionmap.app/tr/
- Korean (한국어): https://lightpollutionmap.app/ko/

### Dark Sky Places

The map highlights International Dark Sky Places, which are locations certified for their exceptional starry nights and protected nocturnal environments. Users can:

- View all certified Dark Sky Places worldwide
- See details about each location including certification year, type, and area
- Find the nearest Dark Sky Place to their location

## Technical Implementation

The web application is built using:

- Astro.js as the core framework
- Leaflet.js for map rendering and interaction
- Chart.js for data visualization and trend analysis
- Tailwind CSS for responsive UI components
- Custom components for UI elements

Data is sourced primarily from NOAA's VIIRS (Visible Infrared Imaging Radiometer Suite) satellite imagery, processed to create light pollution overlays that accurately represent night sky conditions.

## FAQ

### Is this website updated in real-time? How often is the data refreshed?

The website's data is updated periodically. The base light pollution data comes from NOAA's VIIRS data, which is typically updated annually to ensure comprehensive coverage and accuracy. We plan to incorporate additional data sources in the future.

### What does "Bortle Scale" on the map mean? How should I interpret it?

The Bortle Scale is a standard measurement of night sky darkness, used as an indicator for stargazing. It ranges from Class 1 (absolute darkness) to Class 9 (severe light pollution). The lower the scale number, the more stars you can see. The map uses color coding to differentiate between Bortle classes, helping you quickly determine the darkness level of the night sky in any location.

### What is "SQM" and how does it differ from the Bortle Scale?

SQM (Sky Quality Meter) represents night sky brightness in numerical form, measured in mag/arcsec². Higher numbers indicate darker skies. While the Bortle Scale is a classification system, SQM provides precise numerical values. SQM measurements can be converted to Bortle Scale classes for easier interpretation.

### How can I find the best stargazing locations near me?

Our system analyzes your approximate location based on your IP address and automatically displays the Bortle class for that area. You can also search for specific addresses or manually explore the map to discover optimal stargazing spots in other regions.

### Can the map show aurora activity? Are there recommended regions for aurora viewing?

We're in the process of integrating real-time aurora prediction tools (such as KP index) and observation layers into our map. This will help users in high-latitude regions like Northern Europe, Canada, and Alaska track and pursue aurora sightings.

### Can I use this to plan Milky Way photography sessions?

Absolutely! The map combines light pollution levels with geographical data to help you locate ideal spots for Milky Way observation and photography. We're also planning to add features like Milky Way rise times and direction to support astrophotographers in efficiently planning their shoots.

### Is this map optimized for mobile use? Is there an app version?

Our website is fully optimized for mobile devices, providing a smooth experience. You can also check stargazing conditions and light pollution information through the StargazingHub App.

### Which countries or regions are supported? Is it a global map?

Yes, lightpollutionmap.app provides a global light pollution map covering most countries and regions worldwide. It's suitable for astronomy enthusiasts and travelers around the globe. We also offer a Chinese version of the website at Darkmap.cn.

### What's the source of the light pollution data? Is it reliable?

Our data is primarily based on NOAA's VIIRS, and the light pollution map is created by David Lorenz. We'll soon provide light pollution data from the World Atlas 2015, sourced from research by Falchi, Fabio et al.

### How can I share a specific location on the map?

You can go directly to a specific spot by adding coordinates to the URL: `https://lightpollutionmap.app/?lat=25.3125&lng=-80.6875&zoom=8`
Use this to share locations or bookmark your favorite stargazing places. Just change the latitude (lat), longitude (lng), and zoom level.

### Is there a user community or feature for uploading observation reports?

We're planning to build a community for stargazing enthusiasts where users can upload field observation reports, photos, and suggestions. This will enrich our map data and allow users to share their observation experiences.

### Is there a fee for using this service? What premium features are available?

Our website's basic features are permanently free to use. Currently, we don't have plans for a membership program, so you can use our light pollution map with confidence.

### How can beginners get started with night sky observation? How does the map help?

The map helps stargazers quickly find suitable observation locations nearby and provides Bortle class information along with basic astronomical guidance. We plan to expand beginner tutorials and observation recommendations in the future to help you easily start your stargazing journey.

### How can I reduce the impact of light pollution on astronomical observations?

To minimize the effects of light pollution on your astronomical observations, we recommend using Light Pollution Filters. These specialized filters can significantly improve visibility by blocking specific wavelengths of artificial light while allowing starlight to pass through. For quality options, check out Optolong Light Pollution Filters, which offer solutions for both visual observation and astrophotography.

## Related Resources

- [International Dark-Sky Association](https://www.darksky.org/): Organization working to preserve dark skies
- [Globe at Night](https://www.globeatnight.org/): Citizen-science program for monitoring light pollution
- [NASA Night Sky Network](https://nightsky.jpl.nasa.gov/): Astronomy outreach and education resources
- [StargazingHub website](https://laysky.com/): Astronomers' forecast for observing conditions

## Available Versions

- [Light Pollution Map (English)](https://lightpollutionmap.app/): The main English version of the application
- [Light Pollution Map (Spanish)](https://lightpollutionmap.app/es/): Spanish language version
- [Light Pollution Map (Japanese)](https://lightpollutionmap.app/ja/): Japanese language version
- [Light Pollution Map (Polish)](https://lightpollutionmap.app/pl/): Polish language version
- [Light Pollution Map (German)](https://lightpollutionmap.app/de/): German language version
- [Light Pollution Map (Italian)](https://lightpollutionmap.app/it/): Italian language version
- [Light Pollution Map (French)](https://lightpollutionmap.app/fr/): French language version
- [Light Pollution Map (Norwegian)](https://lightpollutionmap.app/nb/): Norwegian language version
- [Light Pollution Map (Russian)](https://lightpollutionmap.app/ru/): Russian language version
- [Light Pollution Map (Turkish)](https://lightpollutionmap.app/tr/): Turkish language version
- [Light Pollution Map (Korean)](https://lightpollutionmap.app/ko/): Korean language version
- [Dark Map (Chinese)](https://www.darkmap.cn/): Chinese language version with similar functionality
- [StargazingHub iOS App](https://apps.apple.com/app/id1478601599): Mobile application for iOS devices