The sky above California was lit with an alien scene Thursday evening as private spaceflight company SpaceX launched 10 of its Iridium satellites. Bystanders captured pictures of the eerie and beautiful spacescape along with their own explanations of what was happening.

SpaceX planned to launch the satellites from Vandenberg Air Force Base near Lompoc, California. The launch of the 10 IridiumNEXT satellites was part of a deal between SpaceX and communications provider Iridium.

Those unaware about the scheduled SpaceX launch proposed alternate explanations like extraterrestrial landings and unidentified objects making their way through the sky. Hashtags like #LAUFO proliferated on Twitter as residents observed the launch.

“Major UFO alert,” one user wrote.

“Strange things happening in El Segundo,” wrote another. “Can someone tell me what is happening?”

Even Elon Musk, the founder of SpaceX, joined the fun.

“It was definitely aliens,” Musk posted on Twitter.

Alongside a separate tweet with a video of the launch, Musk joked: "Nuclear alien UFO from North Korea."

The Ventura County Sheriff’s Office came to the rescue on social media, putting far out fears to bed.

“SpaceX rocket launch from Vandenberg was the flash you saw in the sky!” the sheriff’s office wrote. “No cause for concern.” 

SpaceX confirmed the successful deployment of all the satellites to low Earth orbit shortly after the launch. The company planned to launch additional satellites as part of its deal with Iridium. SpaceX would ultimately replace Iridium's older, outdated satellites with 75 brand new pieces of equipment.