At 6:07 a.m. on Jan. 24, a SpaceX Falcon 9 rocket launched from Vandenberg Space Force Base with 23 Starlink satellites, its sunlit exhaust plume creating glowing clouds across the California sky.
Known as the twilight effect, or the “jellyfish” by rocket spotters, this phenomenon occurs when rockets launched near dawn or dusk create glowing clouds in the upper atmosphere. The effect happens when the rocket reaches high altitudes, where sunlight back-illuminates its exhaust gases against the dark sky.
Social media users from the Bay Area to as far south as Los Angeles reported seeing the launch and the glowing noctilucent clouds it produced as it flew through the sky above California.
Vandenberg Space Force Base, California’s only orbital launch site, regularly hosts private and government satellite launches. The base also conducts missile tests for the Air Force and Space Force.
While Vandenberg hosts regular launches, few occur under the ideal conditions for the twilight effect, often prompting a flurry of social media posts, particularly in the Los Angeles area when it happens.
