A space jellyfish (also jellyfish UFO or rocket jellyfish) is a rocket launch-related phenomenon caused by sunlight reflecting off the high-altitude rocket plume gases emitted by a launching rocket during morning or evening twilight. The observer is in darkness, while the exhaust plumes at high altitudes are still in direct sunlight. This luminous apparition is reminiscent of a jellyfish.^[1][2][3] Sightings of the phenomenon have led to panic, fear of nuclear missile strike, and reports of unidentified flying objects.^{[4][5][6][7][8][9]}

List of rocket launches causing space jellyfish

Rocket launch		Payload	Date	Location	Summary	Notes	References
Falcon 9 flight 232		Transporter 8	12 June 2023	Vandenberg Space Force Base	Afternoon launch – plume observed over Eastern Europe, approximately 75 minutes after launch
Test flight of an unidentified Indian missile		None	15 December 2022	India, Myanmar, Bangladesh	An early evening test launch. Assumed to be of an Agni-V ICBM		[10]
Falcon 9 flight 152		Starlink Group 4–17	6 May 2022	Florida	An early-morning launch causing UFO reports		[11]
Falcon 9 flight 126		Inspiration4	15 September 2021	Florida	The first fully civilian crewed orbital spaceflight, launched from Cape Canaveral after sunset		[12]
Soyuz-2.1.a launch		Progress MS-17	29 June 2021	European Russia	A Soyuz-2.1a launched the Progress MS-17 to the International Space Station from Baikonur Site 31 on 29 June 2021. As the rocket reached the upper atmosphere the expanded rocket plume was illuminated by the sun creating a "jellyfish".		[13][14]
Falcon 9 flight 114		SpaceX Crew-2	23 April 2021	Florida	A crewed Cape Canaveral launch in the pre-dawn. The "jellyfish" lasted over 10 minutes after liftoff. In addition to the "jellyfish" created by the second stage, the returning first stage also made visible plumes.		[15][16][17]
Falcon 9 flight 62		SAOCOM 1A	8 October 2018	California	A West Coast launch off California, in the post-dusk; causing UFO reports		[18][19][20]
Falcon 9 flight 57		SpaceX CRS-15	29 June 2018	Florida	An East Coast launch off Florida, in the pre-dawn		[1]
Soyuz-2.1.b launch		Glonass-M satellite	17 June 2018	European Russia	A launch from the Plesetsk Cosmodrome heading over the cities of Nizhny Novgorod and Kazan, Russia		[8][9][21]
Falcon 9 flight 46		SpaceX Iridium 4[NB 1]	22 December 2017	California	A West Coast launch off California, in the post-dusk		[22]
Atlas V 551 AV-056 flight		MUOS-4[NB 2]	2 September 2015	Florida	A Cape Canaveral launch in the pre-dawn		[23][24]
		Meteor-M2 weather satellite	8 July 2014	European Russia	A launch from Baikonur Cosmodrome, Kazakhstan		[25]
RS-12M Topol-M nuclear missile test launch		—	10 October 2013	Eurasia	Launched from Kapustin Yar, Russia; to crash into Shary Shagan, Kazakhstan		[26]
		Kosmos 1188	14 June 1980	European Russia	A launch from Plesetsk Cosmodrome resulted in a giant U-shaped jellyfish appearing over Moscow and Kalinin, Russia		[27]
		Kosmos 955	20 September 1977	Northern Europe	A launch from Plesetsk Cosmodrome resulted in a jellyfish vapour trail seen over northern Europe, causing the UFO incident known as the "Petrozavodsk phenomenon"		[28]