Data sources and licences

Live data

• NOAA Space Weather Prediction Center — OVATION aurora model, planetary Kp and forecast, real-time solar wind. US Government work, public domain.
• MET Norway Locationforecast — Hourly cloud cover. Norwegian Meteorological Institute, CC BY 4.0.

Historical and climate data

• GFZ Helmholtz Centre for Geosciences — Kp index — Kp since 1932. Matzka et al. (2021), doi:10.5880/Kp.0001, CC BY 4.0.
• NASA POWER — Daily cloud amount (CERES SYN1deg) and temperature (MERRA-2). Obtained from the NASA Langley Research Center POWER Project funded through the NASA Earth Science Directorate Applied Science Program.

Places, terrain and light

• GeoNames — Towns, regions, population. CC BY 4.0.
• Wikidata — Place names in 19 languages. CC0.
• AWS Terrain Tiles (Mapzen/Tilezen) — Elevation data from SRTM, GMTED, ETOPO1, ArcticDEM, NED and others; see the attribution list of the project.
• NASA GIBS — VIIRS Night Lights — Night-time light composite used for light-pollution estimates.
• OurAirports — Airports with scheduled service. Public domain.
• OpenStreetMap — Map links for viewing spots. © OpenStreetMap contributors, ODbL.
• Natural Earth — Base maps. Public domain.

Models and software

• IGRF-14 (IAGA) — Geomagnetic field model used for magnetic latitudes.
• astronomy-engine — Sun, Moon and eclipse calculations. MIT licence.

Photographs

Photographs come from Wikimedia Commons under free licences (CC0, CC BY, CC BY-SA or public domain). The author and licence are shown on each image.

What we changed

We combine and transform these datasets — for example into monthly statistics, viewing angles and a combined score. The original providers are not responsible for our interpretations and do not endorse this site.