About this site
Astrobservatories is an interactive atlas of the world's astronomical observatories — from the giant research telescopes of the Atacama Desert and Mauna Kea to the historic domes of Greenwich, Paris and Athens, radio dishes, solar towers, and public dark-sky observatories.
Every site on the map has details on its telescopes, history, altitude, operating institution, and the darkness of its sky. You can also browse everything as a filterable list by country, type and sky quality.
The Bortle scale
Each observatory carries a Bortle class from 1 to 9 — a widely used scale of night-sky darkness. Class 1 means an exceptional dark-sky site where the Milky Way casts visible shadows; class 9 is an inner-city sky where only the Moon, planets and brightest stars survive. The values shown here are careful estimates based on light-pollution atlas data for each area, not on-site measurements — treat them as a good guide rather than gospel.
The data
The dataset currently covers 154 observatories in 52 countries, spanning active research facilities, radio and solar observatories, historic sites and museums, and notable public observatories. It was compiled from official observatory sites and public astronomical references, and it will never be complete — new observatories are built, old ones close, and hidden gems are everywhere.
Spotted a mistake, or an observatory that deserves to be on the map? Get in touch — corrections and additions are very welcome.
Colophon
Built as a fast, plain static site: no frameworks, no tracking, no cookies. Maps are rendered with Leaflet, basemap tiles by CARTO on OpenStreetMap data.
Astrobservatories is open source — the full code and dataset live on GitHub. Issues and pull requests are welcome, whether it's a new observatory, a data fix, or a feature.