SANTA MONICA—Residents throughout Southern California and Nevada took to social media to report seeing an unidentified bright light flash across the sky. Reported sightings in Southern California included Santa Monica, Anaheim, and Rancho Palos Verdes.

Hundreds of people took to social media to speculate on the origin and nature of the bright light that flashed across the sky Saturday night. In a Daily Voting Poll (@DailyVotingPoll) tweet with over 61,000 votes, 57 percent voted “Yes,” it must be a UFO (taken to mean extraterrestrial) while 43 percent voted “No.”

The San Diego Union Tribune reported that the burst of light seen across two states was in fact a test-launch of a Trident missile by a US Navy submarine. Nearby there is a naval base whose air space is off-limits for commercial airliners.

Some speculated a meteor shower, but the location would not be right for the recent shower, an expert told the Union-Tribune.

The Pentagon said in a statement that the missile was not armed. The Orange County Sheriff’s Department eventually reported via Twitter that the light was a result of missile testing, by tweeting: “Light seen in OC sky was confirmed through JWA tower to be a Naval test fire off the coast. No further details.”