If you've been looking at Twitter or Facebook on Friday evening and have friends in Southern California, you might've seen them post images of a breathtaking sight. It looks like an alien invasion -- or like someone punched a hole in the sky.

In reality, what you saw was a multistage rocket launch. At 5:28 p.m. PT, at California's Vandenberg Air Force Base, a SpaceX Falcon 9 rocket achieved liftoff. It was carrying Iridium-4, a package of 10 Iridium communications satellites designed to be part of an 81-satellite constellation that'll hover in low Earth orbit to deliver data and voice communications, including next-gen air traffic control.

That's awesome. And so was the way the rocket lit up Southern California on Friday. Here are some more images and video, including a fantastic shot by Mike Paule that shows the whole progression.

As of 6:24 p.m. PT, the mission was still underway. You can watch (and rewind) SpaceX's livestream right here.

Update, 6:36 p.m. PT: It's come to our attention that SpaceX founder, CEO and hat salesman Elon Musk tweeted "It was definitely aliens" shortly after the launch. He was probably joking.