Mystery light above L.A. brings fear, anger and questions

The mysterious light flashing across the California sky Saturday night brought fear, fun and even some anger, with some wondering why the public wasn’t told in advance to expect the drama.

NEWSLETTER: Get essential California headlines delivered daily >>

Here’s what we know:

So what was the light?

Navy Strategic Systems Programs conducted a Trident II (D5) missile test flight at sea from the Kentucky, an Ohio class submarine, in the Pacific Test Range off the coast of Southern California.

Has this test occurred in Southern California before?

The Pentagon called the test ongoing and that it occurs on a frequent basis.

The Pentagon said: “The tests were part of a scheduled, ongoing system evaluation test. Launches are conducted on a frequent, recurring basis to ensure the continued reliability of the system. Each test activity provides valuable information about our systems, thus contributing to assurance in our capabilities,” a spokesman told the Los Angeles Times. “The missile was not armed. Strategic Systems Programs does not routinely announce missile testing. Information regarding the test launch of Trident II (D5) missiles is classified prior to the launch.”

Was the public warned in advance?

Apparently not. There was a notice about undisclosed military activity causing a flight path shift at Los Angeles International Airport, but it’s unclear if it was related to the test.

Officials warned that LAX was diverting arriving flights away from normal landing routes to steer clear of temporary military airspace, airport officials announced. The adjusted paths will bring more noise to residential areas directly east of LAX until Thursday.

This all sounds a bit familiar.

Last year, residents along the L.A. County coast insisted they felt an earthquake -- even though seismologists said one had not occurred.

It turned out the shaking came from a supersonic Navy flight. The U.S. Navy confirmed an aircraft flew faster than the speed of sound as part of an exercise with the aircraft carrier Ronald Reagan about 50 miles off the coast.

In 2010, videos flooded the Internet showing an orange tail of vapor seeming to hurtle skyward off the coast of Los Angeles. There was much speculation of some type of secret military launch, but that was never confirmed.

Then, of course, there was the Battle of Los Angeles in 1942. In that infamous event, observers mistook some weather balloons for a Japanese invasion -- or something even worse. Read more on the Battle of Los Angeles here.

Of course, there were many jokes about UFOs. What was the other speculation?

Some thought it was part of the annual Taurid meteor shower, which is reaching its peak. But Brian Keating, an astrophysicist at UC San Diego, quickly dismissed that.