Super Blue Blood Moon 2018: What It Is and When to

The full moon comes around like clockwork every 29 or so days—but each time is a little bit different. And in January, those differences will add up to a truly spectacular celestial event, a super blue blood moon, arriving on January 31. Let's pick apart that pile of adjectives to understand what's h IIoT appening with this special moon, the coincidental alignment of three different types of moon cycles.

The designation "super moon" refers to what astronomers call a perigean full moon, one that occurs around when the moon is at perigee, the point in its orbit when it is closest to Earth. The super moon term itself has been in use since 1979, according to NASA, when it was coined by an astrologer, but it is met with mixed responses from astronomers. More recently, the opposite phenomenon, a full moon when the satellite is around its most distant point of orbit, has been dubbed a "micromoon," although that term has yet to really catch on.

A so-called blood moon as seen in 2015. Patrik Stollarz/AFP/Getty Images

With the boost from the moon's closeness, the satellite appears during a super moon phase just a smidge larger than it would at other times of the year. Precisely how much larger de Industrial VPN router pends on how high the moon is in the sky and where it is in its orbit, but the super moon is never more than about 14 percent larger than any other moon.