Mysterious streaks of light were seen in the sky in the Sacramento area Friday night, shocking St. Patrick’s Day revelers who then posted videos on social media of the surprising sight.

Jaime Hernandez was at the King Cong Brewing Company in Sacramento for a St. Patrick’s Day celebration when some among the group noticed the lights. Hernandez quickly began filming. It was over in about 40 seconds, he said Saturday.

“Mainly, we were in shock, but amazed that we got to witness it,” Hernandez said in an email. “None of us had ever seen anything like it.”

The brewery owner posted Hernandez’s video to Instagram, asking if anyone could solve the mystery.

Jonathan McDowell says he can. McDowell is an astronomer at the Harvard-Smithsonian Center for Astrophysics. McDowell said Saturday in an interview with The Associated Press that he’s 99.9% confident the streaks of light were from burning space debris.

McDowell said that a Japanese communications package that relayed information from the International Space Station to a communications satellite and then back to Earth became obsolete in 2017 when the satellite was retired. The equipment, weighing 310 kilograms (683 pounds), was jettisoned from the space station in 2020 because it was taking up valuable space and would burn up completely upon reentry, McDowell added.

The flaming bits of wreckage created a “spectacular light show in the sky,” McDowell said. He estimated the debris was about 40 miles high, going thousands of miles per hour.

The U.S. Space Force confirmed the re-entry path over California for the Inter-Orbit Communication System, and the timing is consistent with what people saw in the sky, he added. The Space Force could not immediately be reached Saturday with questions.