# Bortle Dark-Sky Scale

> scale of night sky brightness

**Wikidata**: [Q2722595](https://www.wikidata.org/wiki/Q2722595)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Bortle_scale)  
**Source**: https://4ort.xyz/entity/bortle-dark-sky-scale


## References

1. Freebase Data Dumps. 2013