Excess fuel from a Falcon-9 rocket caused a visible spiral vortex in the sky on Monday evening. It was observed across large parts of Austria, including the Vorarlberg, Carinthia, and Styria regions, and was also visible in Germany and other parts of Europe, according to several media reports on Tuesday. A spokesperson from the German Space Command in Uedem, North Rhine-Westphalia, confirmed the phenomenon.

The rocket, launched by SpaceX with a satellite on board, took off from the USA at 6:48 PM Central European Time. Sightings were reported starting at 9:00 PM, according to Hansjürgen Köhler, head of the Central Research Network for Unusual Sky Phenomena (CENAP) in Germany. “We were overwhelmed with calls, WhatsApp messages, and emails with photos of the sightings,” he said. By Tuesday morning, more than 200 reports had been received.

Excess fuel had been released from the rocket’s second stage. As the rocket was rotating, it created a spiral pattern in the sky. The gas remained stable at an altitude of about 100 kilometers due to the thin atmosphere, and because there was still residual sunlight at that height, it remained visible into the evening.

The first stage of the Falcon 9 rocket, the so-called booster, was landed successfully. It re-entered the atmosphere southeast of Madagascar. The second stage of the rocket will eventually burn up.