On March 24, 2025, at around 9:00 PM, an extraordinary phenomenon known as the “cosmic whirlpool” was visible over Poznań (and beyond).
Since July 2024, our Observatory has been equipped with a set of cameras that monitor the sky as part of the AllSky7 Fireball Network Europe. This system is installed on the roof of the main building of the Astrogeodynamical Observatory, part of the Space Research Centre of the Polish Academy of Sciences in Borówiec. Using multiple cameras, we managed to capture this phenomenon. Below, you can find the recordings along with an explanation of the “cosmic whirlpool”.
© Copyright: IOA UAM, AllSky7 Fireball Network Europe.
To fully grasp what happened, we need to rewind to more than two hours before the event. At 6:42 PM, the Falcon 9 rocket carrying the NROL-69 mission launched from Cape Canaveral, Florida, USA. The payload itself is not of concern to us (for context, the mission is entirely classified and was contracted by the National Reconnaissance Office). Instead, our focus is on the rocket’s individual stages.
The first stage is responsible for providing the velocity needed for a suborbital flight (i.e., a flight beyond Earth’s atmosphere). As planned, and in accordance with prior experience, it returned to Earth after a few minutes, successfully landed, and will be reused in future launches.
Falcon9 – cam 2 – 24.03.2025r.
© Copyright: IOA UAM, AllSky7 Fireball Network Europe.
The second stage of Falcon 9 is tasked with accelerating the payload to place it into its target orbit. The flight trajectory was well-known—at approximately 7:09 PM, the rocket passed overhead during its first orbit around Earth, and nearly two hours later, it was set for a second pass after circling the entire planet. After the payload separation, in line with the principle of minimizing space debris around Earth, the second stage was programmed to return from low Earth orbit and burn up in the atmosphere. In February, we observed a failed attempt at such a maneuver, but this time, we had the opportunity to witness a controlled deorbit maneuver.
Falcon9 – cam 3 – 24.03.2025r.
© Copyright: IOA UAM, AllSky7 Fireball Network Europe.
A rocket always carries some reserve fuel to be used in case of unexpected situations. Before the atmospheric reentry maneuver, it needs to dispose of excess fuel—similar to how an aircraft in an emergency landing might dump fuel. Since the rocket is in a vacuum, the expelled gases do not disperse chaotically but instead symmetrically move away from the rocket. A slight rotation of Falcon 9’s second stage causes these gases to form a spiral pattern.
But why can we see them? The answer lies in the Sun. Although it was below the horizon at that hour, it was still illuminating objects hundreds of kilometers above us. At the end of the third video, we can observe the moment the rocket enters Earth’s shadow—causing the entire phenomenon to suddenly disappear. After this planned fuel dump, the rocket was directed into the atmosphere over the ocean.
In summary, the observed phenomenon was the result of a planned and controlled deorbit maneuver, designed to prevent space debris accumulation in low Earth orbit.
2025-03-25, JT, RH
The text was translated with the help of ChatGPT from the Polish version.