Was it a supersonic aircraft?  A meteor?  A ground explosion?  The end of the world as we know it?

Those are the questions experts and non-experts around the world are asking themselves in recent weeks as curiously loud mystery BOOMS have not only been hear around the world, but felt – shaking buildings and rattling nerves from Alabama to Michigan, Idaho to California, Russia to Denmark.

The Alabama boom last Tuesday at 1:39 CST was heard and felt through 11 counties, but an earthquake event has been ruled out.

A sound graph from the U.S. Geological Survey's Lakeview Retreat near Centreville, Alabama, shows a loud boom heard over Alabama at about 1:39 p.m. CST on Nov. 14, 2017.

The day after Alabamans were shaken by that incident, something similar occurred in Idaho. No explanation has been forthcoming from law enforcement officials there.

Then, last Saturday, much the same thing was reported in Michigan, according to various local newscast. Still no explanation.

WXYZ in Detroit said the reports came in from the towns of Wyandotte, Ecorse, Lincoln Park and many others. Wyandotte Police said the loud boom did not originate in their city. Ecorse Police also said their officers heard and felt it inside their police station, but they were not able to pinpoint the source of the sound, saying it did not happen in Ecorse.