Video blogger Julien Solomita was on a Van Nuys rooftop just after nightfall Saturday when he noticed a bright cone of light streaking across the sky. As Solomita followed the mysterious object with his camera for a few minutes, it appeared to him and his friends to explode into a mushroom of light.
"I was wondering, 'Should we run?' It looked so close," he said.
He posted his expletive-filled video to YouTube, titling it "Massive Blue UFO Over Los Angeles." More than 2.5 million people viewed the footage and circulated it widely on social media, helping to drive a frantic online discussion whether aliens were invading, a massive comet had buzzed Earth or something else.
In the end, the explanation was more mundane and terrestrial: A U.S. Navy submarine off the coast had launched an unarmed missile -- one in a series of secret tests the Navy has planned, said John Daniels, a public affairs officer for the Navy's Strategic Systems Programs.
Such tests present military officials with something of a conundrum.
On the one hand, said Loren Thompson, a military analyst with the Lexington Institute, the military needs to give local aviation officials enough information about the time and place of an upcoming test to ensure no planes are in the area.
At the same time, the military is determined to keep tests shrouded in secrecy to thwart any efforts by potential adversaries -- namely Russia and China -- to monitor the missile launch and flight, Thompson said.
The confusion and social media uproar that erupted Saturday night are an unfortunate but unavoidable trade-off, Thompson added.
Daniels acknowledged that the test Saturday and the others scheduled are classified and thus not announced in advance. Although notice was given to aviation officials and sailors in the area, it did not detail the exact time or location of the launch, he said.
The launch, moments after the sun set, created a reflection that made the missile appear brighter, more difficult to discern and visible for far longer than it would have been during the day or at night, Daniels added.
Military officials were unaware beforehand that the launch would offer up such eerie and extended viewing, Daniels said. Had they known, they probably would have prepared a statement to release to the media immediately after the launch, he said.
Navy officials confirmed the test about an hour afterward to the San Diego Union-Tribune.
The need for secrecy Saturday was all the more important given the type of weapon the Navy was testing, according to Thompson.
The Trident II (D5) missile is a centerpiece of the U.S. military's ability to deter a nuclear attack, and an ongoing effort to modernize the weapon is a top priority, he said.
Knowing that a Trident was going to be tested would give prying eyes -- sailors on a Russian submarine in the Pacific, for example -- the ability to gather valuable information, Thompson said. Tracking the missile's trajectory, speed, electromagnetic emissions and other characteristics in real time could provide insights into potential vulnerabilities.
"The Russians and Chinese would have great interest in finding ways to defeat this type of missile," he said.
Solomita said he remains skeptical of the Navy's official explanation.
"I'm not 100% convinced I know what happened, no matter what news channels are saying. I'm kind of remaining skeptical because we were there, and it was crazy," he said.
If it was a missile test, he said, the public should have been better informed.
"Why do a missile test over the second-largest city in the U.S. and not tell anyone? That's pretty wild," he said.
Los Angeles Times Times staff writer W.J. Hennigan contributed to this report.