Aurora Tracker
A live aurora tracker that watches the space-weather that feeds the northern lights minute by minute — the KP index, the magnetic field (Bz), the solar wind and the auroral oval — and folds it all into one 0–9 Aurora Power score, so you can see what the sky is doing right now.
Open the live tracker →What the aurora tracker monitors
Tracking is different from forecasting. A forecast tells you what might happen over the next hours; a tracker tells you what is happening this minute. AuroraSignal pulls a live feed from spacecraft parked at the L1 point — about 1.5 million km sunward of Earth — plus GOES sensors in geostationary orbit and NOAA's ground magnetometer network, and refreshes the picture roughly once a minute. Because L1 sits upstream, the tracker often sees a gust of solar wind 20–60 minutes before its effects reach the ground.
SOLAR-1 & ACE
The L1 sentinels. They sample solar wind speed, density and the magnetic field before it hits Earth — the tracker's earliest warning. Solar wind →
GOES & magnetometers
Geostationary satellites and ground stations register the geomagnetic response as the storm actually arrives. Geomagnetic storms →
Auroral oval
A modeled ring of glow around each magnetic pole, redrawn as conditions change so you can see how far south it reaches. Aurora map →
Aurora Power
One 0–9 score fusing Bz, field strength, wind speed and density into a single glance-able read. See it live →
How to read the live charts
The tracker plots each stream on its own timeline so you can watch trends, not just snapshots. The single most important line is Bz — the north–south tilt of the interplanetary magnetic field. When Bz swings sharply negative (southward) and holds there, it couples with Earth's field and lets solar wind energy pour into the upper atmosphere; that is the moment the aurora brightens. Alongside it, watch the solar wind speed, which typically runs between about 300 and 800 km/s: a jump toward the top of that range, especially paired with rising density, means the wind is hitting harder. The KP index updates on a slower 3-hour rhythm and confirms, after the fact, how strongly the whole planet responded. Read together, a plunging Bz plus fast wind plus a climbing KP is the classic signature of an active night.
Tracking now vs forecasting ahead
Use the tracker and the forecast for different jobs. The tracker answers "should I step outside in the next few minutes?" — it reflects conditions measured moments ago, so a sudden southward Bz turn shows up almost immediately. The forecast answers "is tonight worth planning around?" — it reasons about coronal holes, recurrent high-speed streams and CMEs that may take a day or more to arrive. The two work best side by side: let the forecast decide whether to keep the night free, then let the tracker tell you the exact window to look up.
Tonight
A plain-language read on whether it's worth heading out after dark. Northern lights tonight →
Forecast
The hours-to-days outlook built from solar activity upstream. Aurora forecast →
Alerts
Let the tracker ping you the moment activity crosses your threshold. Aurora alerts →
Turning the numbers into a night outside
Live data only helps if you act on it. When the Aurora Power score climbs, get somewhere with a dark, unobstructed northern horizon well away from town lights, and give your eyes 15–20 minutes to adapt. Aurora often comes in waves — a quiet lull can break into a bright substorm within minutes when Bz snaps south — so it pays to keep the tracker open and stay a while rather than glancing once and leaving. A modest geomagnetic storm (G1–G2) can lift the lights to mid-latitudes when the field stays southward for hours; the rarer strong storms (G3–G5) push the oval much further from the poles.
Aurora tracker FAQ
How often does the aurora tracker update?
The solar wind and magnetic-field streams from the L1 spacecraft refresh about once a minute, so the live charts and the Aurora Power score move on that cadence. The KP index is different — it's an official 3-hour index, so it steps up less often and confirms activity rather than leading it. More on the KP index →
What's the difference between the tracker and a forecast?
The tracker shows measured conditions right now, using solar wind sampled upstream of Earth just minutes ago. A forecast looks further ahead and involves predicting solar activity that hasn't reached us yet, so it carries more uncertainty. Track for the next few minutes; forecast for the night ahead.
Which number should I watch first on the tracker?
Bz. A strongly southward (negative) Bz is the single biggest switch for the aurora — when it drops and holds, energy flows into the atmosphere and the lights brighten, often before the KP index catches up. Pair it with solar wind speed and density for the full picture. Understand Bz & solar wind →
Track the aurora in real time
Live KP index, Bz, solar wind and the auroral oval, distilled into one 0–9 Aurora Power score and refreshed every minute from NOAA and satellite data.
Open the live tracker →