For the first time in nearly a century a full moon is rising on Friday the 13th.  So, if you're a selenophobic, which are people who fear the moon, or suffer from friggatriskaidekaphobia, which is a fear of friday the 13th, you may be afraid to leave the house. Psychologist Dr. Michael McKee says, for some, these fears and superstitions are very real.

"These are real fears. In the U.S. there are millions and millions of people who just want to stay home and not take any chances on either one of these Friday the 13th or a full moon and here they are both together," explained McKee.

He says our fear of Friday the 13th traces all the way back to medieval times. Back then, it seemed like lots of bad things, like hangings and executions happened on Fridays.

The association of bad luck with the number 13 may start with 13 people who attended the Last Supper of Jesus.

McKee says the words "lunatic" and "lunacy" are derived from the word lunar, which is the Latin word for moon.

Some also think the gravitational pull from a full moon may influence our behavior.

"There are some people who really believe that it pulls water in the body the way it does tides in the ocean and that that somehow makes people behave oddly, or makes them more prone to accidents," said McKee.

When you combine a Friday the 13th with a full moon, McKee says it can be a stressful day for some. So, your best bet is to attack it head-on.

"All of these superstitions only have the power that you give them. Otherwise, they are absolutely zero," he said.

The June Moon is also referred to as the "Honey Moon" because of its color and the high number of weddings held in June. In case you're wondering, the next time a full moon rises on a Friday the 13th will be in the year 2049.