Stargazing Hub Team

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

On this site, the Bortle Scale is a public-friendly reference, not the underlying physical quantity. It is useful for a quick read, but if you want a more rigorous comparison between observing sites, pay more attention to SQM and the all-sky skyglow simulation.

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

The site is updated periodically rather than in real time. Update timing mainly follows new annual NOAA VIIRS releases and our production refresh cycle. Because the Bortle label is only a simplified public-facing reference, we recommend using SQM and the all-sky skyglow simulation when you want a fuller view of sky brightness.

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

SQM measures sky brightness in mag/arcsec² and is more useful than a single Bortle class when you want to compare observing conditions. We recommend reading SQM together with the all-sky skyglow simulation, because directional brightness matters and one class cannot describe the whole sky.

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?

This website is fully optimized for mobile devices, so it works smoothly anywhere. You can also check sky conditions and light pollution using the Free Stargazing APP.

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

Yes, lightpollutionmap.app shows light pollution worldwide, covering most countries and regions. It's great for stargazers and travelers. We also offer a Chinese version at Darkmap.cn.