On Sunday, June 23, at 5:15 p.m. UTC (7:15 p.m. CEST) a multi-stage Falcon 9 B5 rocket (the F9-348) was launched from Cape Canaveral Space Launch Complex 40 (SLC-40) in Florida, carrying Starlink Group 10-2, one of several mini-satellite communications groups that Elon Musk's eponymous company has been deploying into orbit since 2019.
Passengers aboard @RoyalCaribbean "Wonder of the Seas" at Port Canaveral are treated to a @SpaceX Falcon 9 launch delivering @Starlink satellites to orbit. pic.twitter.com/ZCoPa01PMu
- Brian OC (@Cudafly01) June 23, 2024
A first attempt to launch the group of 22 satellites had been unsuccessful on the previous June 14, and in preparation for this, the aerospace company replaced the B1073 first-stage booster with the reusable B1078.11. As expected, the latter successfully landed on the Autonomous spaceport drone ship, an operational platform outside Port Canaveral, also in Florida, which has the curious name "A Shortfall of Gravitas" (ASOG).
Two hours later, around 9:15 p.m. CEST (7:15 p.m. UTC), a strange luminous phenomenon of some duration was observed instead, followed in some cases by a persistent green glow from south-central and island Italy, Tunisia, the southern Balkan Peninsula, and Turkey.
Here are some videos or images shared, in the following hours, on X (formerly Twitter):
Southern Latium:
At 9:12 p.m., I caught this unusual bright "effect" in the sky.
I thought of a particular reflection of a passing plane, but I have never seen anything like it.
The shot, in southern Lazio.
Let me know if you've seen it too.@Emergenza24 #news pic.twitter.com/N1QL6q5qya
- DaniDan (@DanieleDann1) June 23, 2024
Palermo:
- Alessia D'Angelo ☢️ (@Alessia1974D) June 23, 2024
Crete Island (Greece):
After the object passed, this green glow remained clearly visible for about ten minutes. What could it be? Spotted in Crete. pic.twitter.com/Ogp5jLVDvU
- thomas (@tommasolab) June 23, 2024
The Italian Center for UFO Studies (CISU) received several testimonies from various regions (Latium, Campania, Apulia, Calabria, Sicily), via the special on-line questionnaire, by e-mail or in the various CISU profiles on social networks.
It was almost immediately assumed that what had been observed was due to the launch that took place in Florida a few hours earlier. To confirm this, we asked Dr. Marco Langbroek, an amateur astronomer and specialist in satellite re-entries, currently a lecturer in optical Space Situational Awareness (SSA) at the Faculty of Aerospace Engineering, Astrodynamics and Space Missions Section of the Technische Universiteit Delft of the Netherlands, for an assessment:
"Starlink G10-2 and the Falcon 9 upper stage [the one responsible for the proper placement of satellites in orbit, not recoverable] passed over the Mediterranean at 19:15 UTC, shortly after the end of the first revolution, two hours after launch. What you are seeing was the exhaust cloud and excess fuel vent from the Falcon 9 upper stage deorbit burn [deorbit maneuver], in preparation for re-entry over the Indian Ocean."
Langbroek adds that the "fuel vent is done to prevent the rocket stage from exploding prematurely upon reentry."
An essentially similar opinion came again on the following day from aerospace engineer Claudio Paris, a professor at the School of Aerospace Engineering at La Sapienza University of Rome and a member of CICAP, as quoted on X by Giuseppe Stilo:
What you can see is the ignition of the re-entry engine (deorbit burn) and the light of the Sun illuminating the 'plume'. And probably also some propellant ejected for re-entry procedures. The very special time-of-day conditions, with the Sun low, made this phase of the launch visible: had it passed over Italy a few hours earlier or later, nothing would have been seen
A similar event, on April 7, 2021, had already caused a flap of reports over Sicily, as CISU Sicilian investigators Antonio Rampulla and Salvatore Foresta reported on their web site. In that case, too, the launch had occurred from SLC-40.
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Collaboration by Arcangelo Cassano, Salvatore Foresta, Gian Paolo Grassino, Stefano Innocenti, Marco Langbroek, Sofia Lincos, Maria Letizia Pellegrino, Edoardo Russo, Giuseppe Santamaria, Giuseppe Stilo
