Where the data comes from
The spacecraft, observatories and models behind every number in Polar Lights.
Polar Lights doesn't make its own measurements. It brings together live data from space agencies and research centres and works out what it means for your place.
The solar wind: DSCOVR and ACE
NOAA's DSCOVR and NASA's ACE spacecraft sit at the L1 point, about 1.5 million km from Earth towards the Sun, measuring the solar wind before it reaches us. Depending on the wind's speed, it takes about 15 to 60 minutes to travel on from L1 to Earth, so that's the warning they give. NOAA's SOLAR-1 spacecraft (launched as SWFO-L1), at the same point since January 2026, also carries the CCOR-2 coronagraph.
The aurora: NOAA's OVATION model
The OVATION model turns the solar wind measured at L1 into a map of the chance of aurora overhead around each pole, for roughly the next 30 to 90 minutes. It updates every few minutes. It drives the Auroral oval map, the map's Aurora layer, the Aurora number in Your sky and the first hours of the Tonight score.
Kp
The Kp index comes from GFZ Potsdam's network of ground magnetometers and NOAA's estimates, with NOAA's forecast for the next three days and its 27-day outlook further ahead.
The Sun
- NASA's SDO (Solar Dynamics Observatory) takes the ultraviolet images, the visible-light picture of sunspots and the magnetogram.
- ESA and NASA's SOHO carries the LASCO coronagraphs that show CMEs leaving the Sun.
- NOAA's GOES-19 satellite carries the SUVI ultraviolet telescope, the CCOR-1 coronagraph and the X-ray sensors that measure flares and the proton sensors behind the radiation scale.
- NASA's DONKI database gives the WSA-Enlil model's forecasts of CME arrival.
Weather and darkness
- Cloud forecasts come from Open-Meteo; the satellite cloud check from EUMETSAT's infrared images.
- Darkness and the Moon are calculated in the app from your position and the time.
- City lights on the map come from NASA's Black Marble.