Data sources
Where each piece of data comes from and what its limits are.
| Source | Used here for | Accuracy and limits | Licence and attribution | Commercial use |
|---|---|---|---|---|
| Solar eclipse path tables NASA/GSFC (F. Espenak) | Paths of totality, annularity and hybrid eclipses, and the centre line. | Points every 2 minutes, with limits interpolated between them. No lunar limb profile. | Reproduction permitted with acknowledgement Eclipse Predictions by Fred Espenak, NASA's GSFC | Permitted Reviewed on 2026-11-04 |
| Decade catalogue of solar eclipses NASA/GSFC (F. Espenak) | Type, regions and cross-checking of the time. | Its times are in TD; they are shown here in UT. | Reproduction permitted with acknowledgement Eclipse Predictions by Fred Espenak, NASA's GSFC | Permitted Reviewed on 2026-11-04 |
| Decade catalogue of lunar eclipses NASA/GSFC (F. Espenak) | Type, including penumbral eclipses, regions and cross-checking of the time. | Its times are in TD; they are shown here in UT. | Reproduction permitted with acknowledgement Eclipse Predictions by Fred Espenak, NASA's GSFC | Permitted Reviewed on 2026-11-04 |
| Total solar eclipse of 2 August 2027 National Geographic Institute (Spain) | Only to cross-check calculated durations; its data and images are not republished. | Published values for Ceuta, Cádiz, Málaga and Melilla. | © IGN; reuse terms still to be reviewed National Geographic Institute (IGN) | Under review Reviewed on 2026-11-04 |
| Astronomy Engine Don Cross | Ephemerides, local circumstances, phases, oppositions, conjunctions and transits. | According to its documentation, around ±1 arcminute. Circular lunar limb. | MIT Astronomy Engine (MIT) | Permitted Reviewed on 2026-11-04 |
| Meteor Shower Calendar 2026 International Meteor Organization | Solar longitude of the maximum, radiant, speed and reference ZHR. | ZHR varies every year: it is a reference, not a prediction. | Factual values cited; document © IMO International Meteor Organization | Under review Reviewed on 2026-11-04 |
| GeoNames (cities15000 and towns in Spain) GeoNames | Gazetteer of towns and time zones. | Town centre point; it is not a viewing spot. | CC BY 4.0 GeoNames (CC BY 4.0) | Permitted Reviewed on 2026-11-04 |
| Wikidata (city names in Spanish and English) Wikimedia Foundation | Names of cities outside Spain in the page language, matched by their GeoNames identifier. | Main label in each language; without one, the GeoNames name is kept. | CC0 1.0 Wikidata (CC0) | Permitted Reviewed on 2026-11-06 |
| OpenStreetMap OpenStreetMap contributors | Astronomical observatories (man_made=observatory) and base map. | Crowd-sourced data; access, opening hours and activity unverified. No prices or astronomy facilities. | ODbL 1.0 © OpenStreetMap contributors | Permitted Reviewed on 2026-11-04 |
| Astronomical viewpoints of La Palma Cabildo Insular de La Palma (island council) | Catalogue places: name, municipality, position, description and link to each viewpoint's official page. | Official data from 2015, before the 2021 eruption: night access and current state not verified on site. | Public-sector information reuse (Spanish Law 37/2007), commercial use allowed Astronomical viewpoints: Cabildo Insular de La Palma (data last updated 8 April 2015) | Permitted Reviewed on 2026-11-07 |
| Starlight certification map Starlight Foundation | Certified reserves, destinations, towns, stellar parks, sites, trails, businesses and places to stay. Only name, type, year, website and position. | One point per place, even for a large area. It doesn't measure the sky or say whether the certification is still valid. | Reuse with the Foundation's permission Certifications: Starlight Foundation, with its permission | Permitted Reviewed on 2026-11-05 |
| Community spots Astrovents users | Observing spots suggested by registered users, with ratings and photos. | Reviewed by moderators before publication, without a site visit. Ratings are opinions and aren't part of the SkyScore. | Licence set in the terms of use (text); CC BY 4.0, CC BY-SA 4.0 or the author's permission (photos) Contributed by the Astrovents community | Permitted Reviewed on 2026-11-06 |
| OpenFreeMap OpenFreeMap | Vector tiles for the base map. | Service with no SLA: it must be reassessed before a high-traffic launch. | Commercial use permitted, no key needed OpenFreeMap, © OpenMapTiles, © OpenStreetMap | Permitted Reviewed on 2026-11-04 |
| Global Imagery Browse Services NASA EOSDIS | Black Marble night lights and clouds observed by satellite. | Satellite radiance from 2016: it is not an SQM reading or a Bortle class. | NASA open data with attribution NASA EOSDIS GIBS | Permitted Reviewed on 2026-11-04 |
| POWER Climatology API (CLOUD_AMT) NASA LaRC | Historical cloud cover climatology, 2001-2025. | 1° grid; monthly average: it is not a forecast. | NASA open data with attribution NASA POWER | Permitted Reviewed on 2026-11-04 |
| Locationforecast 2.0 MET Norway | Hourly forecast within its range of about 9 days. | Numerical model; uncertainty grows with lead time. | CC BY 4.0 Data from MET Norway (CC BY 4.0), adapted | Permitted Reviewed on 2026-11-04 |
| Yale Bright Star Catalogue (5th ed.) Hoffleit and Warren | Stars in the sky view. | Down to magnitude 5, in J2000. | Open astronomical catalogue. Distribution terms still to be confirmed. | Under review |
Data statuses
- Verified: comes from an official source or has been checked against one.
- Calculated / estimated: the result of a model or crowd-sourced data, not individually checked.
- Demo: fictitious, only to demonstrate a feature.
Eclipse catalogue validation
The importer compares the type and time of each eclipse between NASA's tables and Astronomy Engine. If they don't match, it stops and publishes nothing.