The launch happened around 5:30 p.m. right here in Southern California at Vandenberg Air Force Base.
T-60 seconds until launch → https://t.co/gtC39uBC7z
— SpaceX (@SpaceX) December 23, 2017
The sky wasn't the only thing to light up after the launch, however. Twitter and Facebook were ablaze with users posting about the strange-looking light overhead.
Did anyone see this? #SimiValley @ABC7 pic.twitter.com/QEUQ3ybzsa
— Leilani (@randomeizter) December 23, 2017
#Vandenburg #Rocket launch as seen from #VanNuys Airport. @ABC7 #Air7HD pic.twitter.com/hPITKvtJO9
— J.T. Alpaugh (@ABC7JT) December 23, 2017
People from downtown Los Angeles to Orange County to the Inland Empire reported seeing the rocket and its trail in the darkened sky.
My still shot of the @SpaceX launch from #Vandenberg. Wild to see . @ABC7 #abc7eyewitness pic.twitter.com/fsmIFNA2E7
— Greg Lee (@abc7greg) December 23, 2017
The Ventura County Sheriff's Department even tweeted to let residents know there was no reason to be alarmed.
SpaceX rocket launch from Vandenberg was the flash you saw in the sky! No cause for concern.
— Ventura Co. Sheriff (@VENTURASHERIFF) December 23, 2017
This mission sends 10 satellites into orbit, using another used Falcon 9 rocket for the flight.
SpaceX says this is the fourth flight for long-time customer Iridium.
Both companies are under contract to launch a total of 75 satellites to provide communications services for regions all over the world.