Live Scientific Registry
The Stars Are
Waiting for You
Access the nation's most comprehensive database of dark sky discovery.
6,589
Instrumented Cities
290
Scientific Audits
154
Dark Sky Parks
13,178
Local Astronomy Hubs
Foundation
Understanding the
Bortle Scale
Learn how to read the sky like a professional. From city centers to the most pristine darkness on Earth.
Explore Guide
→
Scientific Metric
Sky Quality
Measurement (SQM)
Understand the math behind darkness. How scientists use instrumentation to grade the night sky.
Master the Metric
→