Data Sources & Attribution
Clear-Skies Club relies on trusted astronomical datasets and APIs to provide accurate observation planning. We respect each provider's terms of use and provide proper attribution as required.
JPL Horizons
https://ssd.jpl.nasa.gov/horizons/Purpose
Solar system ephemerides, planetary positions, and orbital mechanics
License
Public domain (U.S. Government work)
Attribution
NASA/JPL-Caltech
Minor Planet Center (MPC)
https://www.minorplanetcenter.net/Purpose
Asteroid and comet orbital elements
License
Free for non-commercial use with attribution
Attribution
International Astronomical Union Minor Planet Center
Pan-STARRS / MAST
https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.htmlPurpose
Deep-sky object imagery
License
Publicly available with attribution
Attribution
Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation.
Digitized Sky Survey (DSS)
https://archive.stsci.edu/dss/Purpose
All-sky photographic survey imagery
License
Publicly available
Attribution
Space Telescope Science Institute / Digitized Sky Survey
NASA Image Library
https://images.nasa.gov/Purpose
Astronomical imagery and photographs
License
Generally public domain unless otherwise noted
Attribution
NASA
N2YO Satellite Tracking
https://www.n2yo.com/Purpose
Satellite orbital data and visible pass predictions
License
API access with attribution
Attribution
N2YO.com satellite tracking service
NOAA GFS (Global Forecast System)
https://www.ncei.noaa.gov/products/weather-climate-models/global-forecastPurpose
Atmospheric forecast data
License
Public domain (US Government)
Attribution
NOAA / National Weather Service
Himawari-9 (JAXA / JMA)
https://registry.opendata.aws/noaa-himawari/Purpose
Satellite cloud imagery
License
Public domain (via NOAA AWS Open Data)
Attribution
Japan Meteorological Agency / NOAA
OpenWeather
https://openweathermap.org/Purpose
Weather forecasts
License
API subscription (ODbL for data)
Attribution
OpenWeather
HYG Star Database
https://github.com/astronexus/HYG-DatabasePurpose
Star catalog for bright stars and constellations
License
CC BY-SA 4.0
Attribution
Compiled by David Nash from Hipparcos, Yale Bright Star, and Gliese catalogs
Licensing & Commercial Use
We cache and attribute data according to each provider's terms of service. Most sources permit free use for typical astronomy applications with proper attribution.
For high-volume commercial use or API rate limit upgrades, additional licensing may be required from individual providers. We will surface any necessary licensing information to commercial users as needed.
Last updated: July 2026
Questions about data usage or licensing? Contact us