Triskaidekaphobics may be staying indoors this Friday, but this Friday the 13th also brings a beautiful celestial event. This Friday the 13th will coincide with a full honey moon, which will reach full moon phase at 12:13 a.m. EDT on Friday morning for eastern North America. However, its honey hues will shine most brightly in the early evening.
The amber color is due to the scattering of longer wavelengths of light by dust and pollution in our atmosphere. “It is a similar phenomenon as seen at sunset, when sunlight is scattered towards the red end of the spectrum, making the sun’s disk appear orange-red to the naked-eye,” says astronomer Raminder Singh Samra of the H. R. MacMillan Space Centre in Vancouver, Canada.
The monthly full moon always appears as a large disk, but because its orbit around the Earth is elliptical rather than perfectly circular, there are times in the lunar cycle when the moon is at its shortest distance from Earth (called perigee), some 224,976 miles away (apogee refers to its farthest distance from Earth).
This month the perigee just happens to coincide with the full phase, which may make it appear unusually large to sky-watchers. “The moon illusion should be more prominent during this full moon as it will graze closer to the horizon than at any other time of the year,” Samra says. “This will make the moon appear more amber than other full moons of the year.
A full moon coinciding on Friday the 13th is not all that uncommon, occurring every three or so years. But a honey moon coinciding with Friday the 13th is rare, last occurring on June 13, 1919, according to Universe Today. The next one won’t occur until June 13, 2098.