The mysterious bright lights that streaked the night sky of the Pacific Northwest on Thursday weren’t planes or meteors, but debris from a SpaceX rocket.

At least that’s what the experts said. But not everyone got the memo, so there was a lot of confusion.

“We got a number of calls about it!” The Portland office of the National Weather Service said on Twitter.

Moments later, it added – with the caveat that it was not an expert in rocket science – that the “widespread bright objects in the sky” appeared to be debris from a SpaceX rocket that “did not have a successful deorbit burn”.

A “deorbit fire” is the technical term for the case that a spaceship turns with the stern first and fires its rockets before it gets back into the earth’s atmosphere.

Jonathan McDowell, an astronomer with the Harvard-Smithsonian Center for Astrophysics, wrote on Twitter that what people saw in the Pacific Northwest on Thursday evening was part of a SpaceX Falcon 9 rocket that launched in early March. The debris returned to the atmosphere after 22 days in orbit, he said.

Falcon 9 rockets have been transporting cargo and satellites into space for years. SpaceX used a Falcon 9 last year when it was the first private company to put astronauts into orbit.

Mr. McDowell wrote that the “space debris” visible over Seattle was the result of a separation that occurred about 30 miles above the airfield from aircraft. The falcon 9 debris falling to earth is “likely not large,” he added, and would most likely fall in the Rocky Mountains near the Canadian border.

SpaceX launches take place regularly in California, Texas, and Florida. For some Americans, it is now normal – or at least normal – to see unidentified missiles or their debris whizzing overhead.

But it’s still pretty weird and disoriented for the people of the Pacific Northwest.

In the Seattle and Portland areas, Thursday night’s spectacle seemed to create more joy and confusion than fear.

One user grumbled that she had somehow missed it. Another wondered how astronomers on the Internet had managed to solve the mystery so quickly, even though a ship was stuck in the Suez Canal for days.

Others took the opportunity to pinch Elon Musk, the founder and CEO of SpaceX.

“Um … just caught that flight over my house in SW Portland,” wrote a Twitter user, Vince LaVecchia, just after 9 p.m. local time. “@ Elonmusk your rocket?”

The SpaceX Twitter feed hadn’t weighed on the mysterious Pacific Northwest light show early Friday morning. Neither Mr. Musk nor NASA. The California-based company could not be immediately reached for comment.

But the National Weather Service staff stayed up late tweeting their astronomical impressions – and they seemed to be having fun.

“A little disappointing given the events of the evening, but the Orion Nebula looks beautiful from our roof tonight,” the agency’s Seattle office wrote, referring to a constellation. “Another satellite managed to take a picture of the picture.”

Mike Baker and Nicholas Bogel-Burroughs contributed to the coverage.