A mysterious light formation seen early this evening set off some wild speculation on social media platforms by East Bay residents. Was it a rocket launch? Space junk reentering the earth’s atmosphere? Aliens … Santa?!
— RookiiUnderrated (@RookiiURN) December 20, 2018
— Kami (@pumpkam) December 20, 2018
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Coincidentally, a planned rocket launch from Vandenberg Air Force base caused further confusion. It was determined that this launch had been scrubbed due to a hydrogen leak thus eliminating this theory.
The Reno National Weather Service posted a time-lapse video from the evening that captured the formation.
The Delta IV rocket launch was scrubbed this evening at Vandenberg AFB. Did anyone else see this beautiful sunset and light in the western sky? This is a view from the Diamond Peak @NVSeismoLab AlertTahoe camera. pic.twitter.com/2ekBnRfFRq
— NWS Reno (@NWSReno) December 20, 2018
Whatever it was, it could be seen as far away as Nevada and left a persistent, glowing trail for several minutes afterward. The trail was soon altered by the wind to create a unique, spiral shape that ironically resembled a question mark.
The Bay Area National Weather Service speculated that it was a meteor that had created a high level cloud called a “noctilucent cloud.” Noctilucent clouds, according to NASA, are created by pecks of meteor smoke which act as gathering points where water molecules can assemble themselves into ice crystals. This process is called “nucleation.”
Still not 100% certain, but evidence is growing the object seen was a meteor. A meteor can create a very high level cloud called a noctilucent cloud. @NASA has a great webpage explaining the cloud formation. https://t.co/eDquECamLl #cawx
— NWS Bay Area (@NWSBayArea) December 20, 2018
San Jose’s Lick Observatory stepped in via their facebook page to confirm the mysterious phenomenon. “A bright meteor was visible in the skies over the Bay Area shortly after sunset this evening, leaving a bright trail that was visible for many minutes in the western sky.”
The last known visible occurrence of this type of formation in the Bay Area was 2011. Lick Observatory is owned and operated by the University of California system and has been providing UC astronomers with access to observing equipment since 1888.
Feature Image: Erick Harrison via Twitter