Residents of central Maine were startled by a loud, mysterious boom which was heard throughout several counties on the evening of Sunday, April 9th. Area residents took to Facebook to ask if others heard the sound, and a few residents claimed the ground shook from the force of the noise. One resident even reported a glass shower door exploding from the tremor. Whatever it was, it was big.

Police reported dozens of calls from several different cities in central Maine.

Maine state police and public safety officials currently do not know what the source of the boom could have been. There was some initial speculation that it could have been related to a car fire or a nearby propane tank fire, although those should not have been loud enough to have been heard over such a large area as the boom was. Interestingly, several power substations experienced failures shortly after the boom was heard, but Central Maine Power claims the events were unrelated.

Local residents ruled out the power substation explanation on their own.

According to the Bangor Daily News, spokesmen for both the Maine Air National Guard and Maine Army National Guard claim that neither has any aircraft capable of producing sonic booms, ruling out speculation that a military aircraft could have caused the boom. A spokesman for the FAA also reported that no sonic booms were reported in the area.

Of course, if there were secretive tests or drills in the area, they wouldn’t exactly tell us, would they?

Andy Pohl, a meteorologist at the National Weather Service in Maine, told CentralMaine.com that there were likewise no weather phenomena in the area which could have caused such a violent noise:

We didn’t have anything on the radar. It was a quiet evening. We have no idea what it could have been.

 There goes the icequake theory. Also, apparently icequakes are a thing. A few months ago, residents of Connecticut a few hundred miles to the southwest heard similar booms which went unexplained, while a few weeks later on the opposite coast, San Diegans were also terrified by a mystery boom. What is happening in the skies above America’s coastlines? Military testing? Strange atmospheric phenomena? What about the good ol’ exploding meteorite? Each is equally plausible at this point. 

Maine and mystery booms just go together, I suppose.