#astronomy 

The Bortle dark-sky scale is a nine-level scale that measures the night sky's brightness.

Created by an amateur astronomer John E. Bortle in 2001.


## Scale
| Bortle level | Description               |
| ------------ | ------------------------- |
| 1            | Excellent Dark Sky Site   |
| 2            | Dark Sky Site             |
| 3            | Rural Sky                 |
| 4            | Suburban/Rural Transition |
| 5            | Suburban Sky              |
| 6            | Bright Suburban Sky       |
| 7            | City/Suburbia Transition  |
| 8            | City Sky                  |
| 9            | Inner City Sky            |
![[Pasted image 20240621001057.png]]