As with walking under a ladder, crossing paths with a black cat or breaking a mirror, many people hold fast to the belief that Friday the 13th brings bad luck. When combining that with the superstition that spooky things happen during a full moon, Friday, Sept, 13, is considered by some to be especially ominous as it includes both.

Although it's uncertain how some of traditions got started, negative superstitions have surrounded the number 13 for centuries. Fear of the number 13 is called triskaidekaphobia.

According to the History Channel's, the ancient Code of Hammurabi, for example, omitted a 13th law from its list of legal rules.

“The Code of Hammurabi was one of the earliest and most complete written legal codes and was proclaimed by the Babylonian king Hammurabi, who reigned from 1792 to 1750 B.C.,” states the site.

The seating arrangement at the Last Supper is also believed to have given rise to a longstanding Christian superstition that having 13 guests at a table was a bad omen.

“Though Friday’s negative associations are weaker, some have suggested they also have roots in Christian tradition. Just as Jesus was crucified on a Friday, Friday was also said to be the day Eve gave Adam the fateful apple from the Tree of Knowledge, as well as the day Cain killed his brother, Abel,” states the history site.

According to Donald Dossey, author of “Holiday Folklore, Phobias and Fun,” a Norse myth told of a dinner party for 12 gods at which a 13th guest showed up uninvited. The gatecrasher was the trickster god Loki, who shot the god of joy and happiness, Balder.

While the origins of superstitions surrounding full moons and Friday the 13th are unclear, what is clear is how rare it is to have both on the same day. This Friday marks the first time since 2000 that a full moon occurred on Friday the 13th. The event will not occur again until 2049.

Making the event even more rare, the Sept. 13 full moon will occur near apogee, which is the most distant point in the moon’s orbit. The last time this happened was in 1832. It won’t happen again for 505 years.