An unusual phenomenon could be observed in the Polish sky on Monday, March 25. Just after 9 p.m., a bluish, shimmering spiral resembling a vortex appeared over Poznań. According to astronomy popularizer and author of the “Head in the Stars” website Karol Wójcicki, what could be seen was the discharge of fuel from the Falcon 9’s second stage tanks.
At 18:48 Polish time, SpaceX’s Falcon 9 rocket took off from the SLC-40 launch complex at Cape Canaveral Space Force Station in Florida with the classified NROL-69 mission commissioned by the National Reconnaissance Office (NRO). The NROL-69 mission was intended to launch the USA-498 satellite, whose exact destination remains secret due to the military nature of the payload.
As explained by the author of the “Head in the Stars” website, after the launch phase, the Falcon 9 rocket’s first stage returned to Earth, landing at Landing Zone 1 at Cape Canaveral. This was its second successful flight – it had previously supported the Starlink mission.
Due to its flight trajectory and orbit inclination of 51 degrees, the rocket’s overflight was visible in the sky over Poland. During the second flight over our country, Falcon 9’s second stage made a fuel dump before the planned deorbit.
As an expert pointed out in a Facebook post, a residual fuel dump often occurs before the rocket’s second stage enters the atmosphere and burns up. If the rocket rotates around its axis, the fuel released from the jets is arranged in the shape of a spiral, resembling a galaxy. Such a cloud, illuminated by the sun still below the horizon, can look like a luminous vortex swirling against the darkening sky.
