The screen begins empty. What you see builds over time, you are watching the sky draw itself. Each aircraft within 250 km of Paris Charles de Gaulle leaves a hairline trace, barely perceptible on its own. Individually these marks are near-invisible; collectively they accumulate. The approach paths and departure routes of one of Europe's busiest hubs slowly materialize, the funnel of descending aircraft from the north, the tight holding stacks above the Île-de-France, transatlantic arrivals arcing in from the west.

Colour encodes altitude: warm amber near the ground, shifting to near-white blue at cruising height around 10,000 m. Brightness is pure accumulation, the more traffic has passed through, the brighter the trace.

Data provided by The OpenSky Network. Refreshes every ~30 seconds.