The spiral structure appeared over Maunakea on January 18,Screenshot: Gizmodo/Subaru Telescope
Last week, astronomers at a Hawaiian observatory spotted a spiral-like structure over Maunakea. A SpaceX Falcon 9 upper stage is the likely source of the strange atmospheric feature, as this sort of thing has happened before.
The spiral was seen during the early morning hours of January 18, the same day that a Falcon 9 rocket blasted off from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida. A tweet from Subaru Telescope astronomers provided a glimpse of the spectacle, which the scientists linked to SpaceX’s launch of a new satellite.
A “Mysterious” Flying Spiral over Maunakea 2023-01-18 UT / マウナケア上空にまた渦巻き出現！
The observatory also provided a time lapse video of the spiral, showing its evolution over time, along with an unsettling number of satellites zipping by. “Earlier that day, SpaceX launched a satellite to medium-Earth orbit,” Subaru Telescope said in the video. “We believe this phenomenon is related [to] its orbital deployment operation.” SpaceX’s GPS III Space Vehicle 06 mission did in fact launch earlier in the day, delivering a GPS satellite for the U.S. Space Force.
The Subaru Telescope is a 26.9-foot (8.2-meter) optical-infrared telescope located on the summit of Maunakea and operated by the National Astronomical Observatory of Japan. The team used the facility’s Subaru-Asahi Star Camera to spot and chronicle the spiral.
That a rocket could cause such an atmospheric formation seems surprising, but this isn’t the first time that a SpaceX rocket has caused such a structure to form; a similar “smoke ring” seen over Illinois on June 19, 2022 was linked to the launch of a Falcon 9 and the delivery of the Globalstar FM15 satellite.
“This spiral was caused by the Falcon 9’s upper stage venting leftover fuel just before deorbiting into the Pacific Ocean,” Spaceweather reported at the time. “The upper stage was probably spinning on its longest axis to stabilize flight orientation—hence the spiral shape,” and similar spirals “have been seen after previous Falcon 9 launches.”
Falcon 9 launches are known for producing strange atmospheric effects, including bow shocks (as seen in the new video) and rocket “jellyfishes.” Sights like this are set to be a common occurrence, with SpaceX planning more than 100 Falcon 9 launches in the coming year.