Rocket fans in California may have been disappointed by tonight’s scrub of a Delta 4 Heavy launch from Vandenberg Air Force Base, but they received a nice consolation prize: a fireball that left what looked like a contrail hanging in sunset skies.
The bright squiggle in the sky may have mystified some, but savvy folks who spotted the flash recognized it as the signature of an exploding meteor, also known as a bolide.
It was pure coincidence that the fireball flashed at 5:34 p.m. PT, just before United Launch Alliance called off the launch of a classified spy satellite known as NROL-71 for the National Reconnaissance Office, due to elevated hydrogen levels that were detected during the countdown.
Video views captured from cars traveling in locales including Sacramento, Stockton and the San Francisco Bay Area helped solve the celestial mystery. Here are a few of the best clips:
https://twitter.com/Richifornia/status/1075569646030381056
https://twitter.com/aririn/status/1075602875907076097
https://twitter.com/_starbase_/status/1075579883353501696
https://twitter.com/CBSSacramento/status/1075568640907341824
And here are more views from social media:
https://twitter.com/jaredhead/status/1075571286976344064
https://twitter.com/SpacecoastPix/status/1075579994741436416
https://twitter.com/agweeds707/status/1075569683820994561
https://twitter.com/opbphotos/status/1075597387660324864
https://twitter.com/AllPlanets/status/1075567908925796352
SETI Institute senior planetary astronomer Franck Marchis was wrong about the airplane exhaust, but he was right about the intriguing nature of the meteor trail. German science writer Daniel Fischer pulled together a lot of the imagery — and pieced together a sensible explanation:
https://twitter.com/cosmos4u/status/1075584308063191040
The NROL-17 launch had to be put off until Dec. 30 at the earliest so that United Launch Alliance could address the Delta 4 Heavy rocket’s accumulation of excess hydrogen.
SpaceX’s scheduled launch of an Air Force GPS III satellite from Florida was also postponed today, due to weather, and it may be postponed again on Thursday for the same reason. But today wasn’t a total washout for rocket fans.
India sent up a GSLV rocket with the Indian Air Force’s GSAT-7A remote-sensing satellite, while Arianespace launched the French CSO-1 spy satellite from its spaceport in French Guiana with a Russian-built Soyuz rocket.
Who knows? Maybe there’ll be another sunset fireball to celebrate a successful Delta 4 Heavy launch — after what are now four postponements.
Fireball sighting reports can be filed with the American Meteor Society, which has already received more than 100 reports (and scores of photos).