Unlike some of the whistles or hums heard in other parts of the world, the mystery sound in Alhambra, California is described as a “loud, booming noise that sounds louder than a firecracker explosion.” Residents say there have been about 100 of these explosions since February of this year.
Fox News being Fox News, the article closes with this inane tidbit:
[Town resident] Saunders is interested to see how long the booms will be a mystery. But whether the noise is something extraterrestrial, she expressed some doubt, according to NBC Los Angeles.
“I believe that anything’s possible, but I don’t think these are aliens,” Saunders said.
If we had to guess, the logical explanation would be police or military weapon testing. But it’s just a guess.