README.md

---
license: cc0-1.0
pretty_name: "Observatory Database"
language:
  - en
description: >-
  Comprehensive database of astronomical observatories worldwide, sourced from Wikidata.
  609 observatories from 60 countries with coordinates, elevation,
  aperture size, operator, and wavelength coverage.
size_categories:
  - n<1K
task_categories:
  - tabular-classification
tags:
  - space
  - astronomy
  - observatories
  - telescopes
  - wikidata
  - open-data
  - tabular-data
  - parquet
configs:
  - config_name: default
    default: true
    data_files:
      - split: train
        path: data/observatories.parquet
---

# Observatory Database

*Part of the [Astronomy Datasets](https://huggingface.co/collections/juliensimon/astronomy-datasets-69c24caf2f17e36128946743) collection on Hugging Face.*

Comprehensive database of astronomical observatories — **609** facilities from
**60** countries, sourced from [Wikidata](https://www.wikidata.org/).

## Dataset description

From ancient naked-eye platforms to modern space-based flagship missions, observatories
have been humanity's primary windows into the universe. This dataset covers optical
telescopes, radio dishes, neutrino detectors, gamma-ray satellites, and space observatories —
any facility classified in Wikidata as an astronomical observatory (Q62832), space
observatory (Q1377879), or radio observatory (Q148578).

Each entry includes geographic coordinates (latitude/longitude), elevation above sea level,
primary aperture size, operating organization, opening date, and the electromagnetic
wavelength bands observed. This enables spatial analysis of observatory distribution,
historical studies of observational astronomy, and comparison of ground-based vs.
space-based capabilities.

Sourced from Wikidata's structured knowledge base, curated by the WikiProject Astronomy
community with contributions from professional astronomers and enthusiasts worldwide.

## Schema

| Column | Type | Description |
|--------|------|-------------|
| `wikidata_id` | string | Wikidata entity ID (e.g. Q179224) |
| `name` | string | Observatory name |
| `country` | string | Country where the observatory is located |
| `latitude` | float | Geographic latitude (decimal degrees) |
| `longitude` | float | Geographic longitude (decimal degrees) |
| `elevation_m` | float | Elevation above sea level (metres) |
| `aperture_m` | float | Primary mirror/dish aperture (metres) |
| `operator` | string | Operating organization or agency |
| `opening_date` | string | Date the observatory opened (YYYY-MM-DD) |
| `wavelengths` | string | Observed wavelength bands, semicolon-separated |

## Quick stats

- **609** observatories from **60** countries
- **357** with geographic coordinates
- **0** with aperture data
- **46** with elevation data
- Highest elevation: Caltech Submillimeter Observatory (13,570 m)
- Estimated ground-based: **510**, space-based: **99**
- Top countries: United States (109), United Kingdom (43), Italy (25), France (24), Netherlands (19)
- Top wavelength bands: 

## Usage

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/observatory-database", split="train")
df = ds.to_pandas()

# Observatories by country
print(df["country"].value_counts().head(10))

# High-altitude observatories (above 3000 m)
high_alt = df[df["elevation_m"] > 3000].sort_values("elevation_m", ascending=False)
print(high_alt[["name", "country", "elevation_m"]].head(10))

# Large aperture telescopes (> 8 m)
large = df[df["aperture_m"] > 8].sort_values("aperture_m", ascending=False)
print(large[["name", "country", "aperture_m"]])

# Radio observatories
radio = df[df["wavelengths"].str.contains("radio", case=False, na=False)]
print(f"{len(radio):,} radio observatories")

# Space observatories
space_obs = df[df["wavelengths"].str.contains("X-ray|gamma|ultraviolet", case=False, na=False)]
print(space_obs[["name", "wavelengths"]].head(10))
```

## Data source

[Wikidata](https://www.wikidata.org/) SPARQL endpoint. Observatories identified via
property P31 (instance of) = Q62832 (astronomical observatory), Q1377879 (space
observatory), or Q148578 (radio observatory). Data is community-curated by
[WikiProject Astronomy](https://www.wikidata.org/wiki/Wikidata:WikiProject_Astronomy).

## Update schedule

Quarterly (January, April, July, October). Re-run manually to pick up newly catalogued facilities.

## Related datasets

- [astronomer-database](https://huggingface.co/datasets/juliensimon/astronomer-database) — Astronomers from Wikidata
- [chandra-sources](https://huggingface.co/datasets/juliensimon/chandra-sources) — Chandra X-ray source catalog

## Pipeline

Source code: [juliensimon/space-datasets](https://github.com/juliensimon/space-datasets)

## Support

If you find this dataset useful, please give it a ❤️ on the [dataset page](https://huggingface.co/datasets/juliensimon/observatory-database) and share feedback in the Community tab! Also consider giving a ⭐️ to the [space-datasets](https://github.com/juliensimon/space-datasets) repo.

## Citation

```bibtex
@dataset{observatory_database,
  author = {Simon, Julien},
  title = {Observatory Database},
  year = {2026},
  publisher = {Hugging Face},
  url = {https://huggingface.co/datasets/juliensimon/observatory-database},
  note = {Sourced from Wikidata (CC0)}
}
```

## License

[CC0-1.0](https://creativecommons.org/publicdomain/zero/1.0/) (Wikidata content is public domain)