Final SpaceX rocket launch of 2017 lights up Southern California sky

LOS ANGELES -- Did you see something bright in the sky? You may have seen the launch of the 18th, and final mission of the year for SpaceX Friday night.

Many Southern Californians saw the final SpaceX launch of 2017 Friday night, and they're all tweeting about it.

The launch happened around 5:30 p.m. right here in Southern California at Vandenberg Air Force Base.

ABC7 viewers shared photos of a bright light in the sky in Southern California on Friday, Dec. 22, 2017.

Photo submitted to KGO-TV by Carlos Armas/Facebook

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.

People from downtown Los Angeles to Orange County to the Inland Empire reported seeing the rocket and its trail in the darkened sky.

The Ventura County Sheriff's Department even tweeted to let residents know there was no reason to be alarmed.

And SpaceX founder Elon Musk tweeted about the instantaneous social media reaction as well.

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.