Beach-goers seeking a romantic evening under the stars on Saturday in Southern California got quite a surprise. Shortly after sunset, a fireball overhead sparked widespread confusion and speculation. Was it a meteor, rocket, or, perhaps, an alien spacecraft? By late Saturday, it was confirmed to be a multi-stage missile test from a US Navy submarine.

The military provided no advance information about a launch. However, in the immediate aftermath, some key clues did emerge. Earlier in the week, Los Angeles International Airport—which normally routes flights over water instead of nearby residential areas to reduce noise—announced it was temporarily diverting flights from sea-based landing routes to steer clear of air space requested by the military. Then, about an hour after the fireball was widely reported on social media, the Orange County Sheriff's Department tweeted that the light seen over southern California was "a Naval test fire off the coast."

Later on Saturday, a US Navy spokesman finally confirmed that the fireball was, in fact, a Trident II (D5) missile test flight at sea from the Kentucky, an Ohio-class ballistic missile submarine. This Trident missile, which has three stages that matched amateur videos of the event, has a range of 7,360 km. It is part of the country's triad of nuclear deterrents, including land-based missile systems and manned bombers.