On February 9, 1913, a unique procession of meteors was observed from Canada, parts of the US, and in one case, off the coast of Brazil. Several streams of brilliant meteors were seen moving relatively slowly across the sky; the event lasted too long for a regular meteor sighting, but too short for a regular meteor shower, and moreover, the meteors did not, like showers, radiate from a single point in the sky. Most of North America was cloudy that day, so out of the millions of potential observers, only hundred-odd reports were made, mostly from remote locations, but there is no doubt that it happened. The meteors were accompanied by a trembling sound.
Comparing eyewitness reports and making calculations of possible trajectories, scientists have proposed a remarkable possibility: that this event, called by some the Cyrillid meteor shower, was a short-lived natural satellite of the Earth. (This view is not undisputed.) Natural satellites, especially bigger ones, are more conventionally called moons. If this hypothesis is true, the most likely explanation for the 1913 event is that some small celestial object, after however many round-trips around the Sun, got caught in orbit around the Earth, for a brief while giving us a second, tiny moon, until it broke apart into a brilliant procession of meteors.