Night Sky Alert
Credits

Data & credits

Night Sky Alert stands on public data and open-source work. Thank you to all of these.

Data

  • NOAA Space Weather Prediction Center: planetary Kp index forecast and OVATION aurora model. US government data in the public domain. Night Sky Alert is not affiliated with or endorsed by NOAA or the National Weather Service. Our scores and visibility estimates are our own interpretation, not official NOAA products.
  • MET Norway (Norwegian Meteorological Institute): Locationforecast cloud and fog forecasts. Weather data from MET Norway, licensed under CC BY 4.0. We average and transform it into an "effective cloud" value.
  • The Space Devs, Launch Library 2: rocket launch schedules and pad locations. thespacedevs.com.
  • CelesTrak: orbital elements for the International Space Station. celestrak.org. Pass predictions verified against NASA Johnson Space Center's published ISS trajectory. Not endorsed by NASA.
  • GeoNames: city names, locations, populations and time zones. Licensed under CC BY 4.0. geonames.org.
  • American Meteor Society: meteor shower names and dates (facts only; descriptions are ours). amsmeteors.org.
  • Natural Earth: coastlines and lakes for the aurora map (public domain).

City coverage: every place in GeoNames with at least 50,000 people in the United States and Canada, and at least 100,000 elsewhere (neighbourhoods excluded).

Software

  • astronomy-engine (MIT): Sun, Moon and twilight.
  • satellite.js (MIT): SGP4 orbit propagation.
  • Fonts: Fraunces and Inter Tight (SIL Open Font License).