For as long as man has gazed upward, we’ve been enchanted by the Moon, the Earth’s only permanent natural satellite. Its constant prominence in our night sky and its waxing and waning dance over the course of the lunar month has influenced human culture since the dawn of time itself. Its regularity made it an ideal early calendar and helped formed the basis for the modern ~30-day month we use today.
The downside of omnipresence, however, is that we often come to take those things for granted. We’re so used to seeing the Moon that we often forget to look up and appreciate its natural beauty. That’s why, every now and then, we need to be reminded of its unparalleled ability to inspire awe – and sometimes mass hysteria – across the globe.
This is exactly what happened last month when the Moon teamed up with the Earth and Sun to create a spectacular total lunar eclipse. This phenomenon occurs when the Sun, Earth, and Moon are exactly or very closely aligned, with the Earth in the middle. In this process, the Moon passes directly behind Earth and into its shadow, turning an ominous red color.
As if that wasn’t cool enough already, the eclipse coincided with a supermoon and the Full Wolf Moon, earning it the title “Super Blood Wolf Moon.”
Arguably that name alone raises more questions than it does answers, questions like what is a supermoon? And what the heck is a Full Wolf Moon? And perhaps most confusingly, why are we writing about this in an online magazine dedicated to watches?
Read on for the answers to all these questions and more.
Full Moon vs. Supermoon
The first thing to know is that a full moon and a supermoon are not the same thing. That probably seems redundant to most of you reading this, but it’s worth getting our facts straight from the outset. A full moon is defined as the phase of the Moon in which its whole Earth-facing side is illuminated. This occurs once every lunar month, meaning there are 12 full moons per year on average.
What you may not know, though – I didn’t either – is that each full moon has a name. According to National Geographic, ancient cultures the world over gave the full moons names based on the behavior of the plants, animals, or weather during that month. So, in January, the full moon is called the “Wolf Moon” because hungry wolves used to howl through the cold winter nights.
The next full moon will be on February 19th and is commonly called the “Snow Moon” after the typically snowy weather in North America in February. Confusingly, it too will be a supermoon and will be the closest and largest full supermoon of 2019.
That’s all well and good, but just what is a supermoon I hear you asking?
Well, it all comes down to proximity. Basically, a full moon or new moon is deemed a supermoon when it closely coincides with the perigee, the Moon’s closest point to Earth in its monthly orbit. This happens around 4 – 6 times a year. The original definition, coined by a guy named Richard Nolle in 1979, specifically states that the Moon has to come within 90 percent of its closest approach to Earth to be considered a supermoon.
Apparently, supermoons don’t look any bigger to us than ordinary full moons, but they are definitely noticeably brighter. That’s because, according to EarthSky, a supermoon exceeds the area and brightness of an average-sized full moon by some 15 percent.
As I mentioned above, what made last month’s supermoon such a visual spectacle was the fact that it coincided with a total lunar eclipse, resulting in a “blood moon.” If you saw it for yourself or have seen pictures, you can probably guess where the name comes from. But what’s the science behind it?
Let’s cover the basics first. The Moon orbits the Earth, and the Earth orbits the Sun. That much is obvious. The trick is that the Moon orbits on a slightly different plane than the Earth and Sun, and every so often, these planes overlap. At this point, the Moon is fully in Earth’s shadow. At the same time, light from Earth’s sunrises and sunsets falls on the Moon’s surface. Since these light waves are stretched out, they look red. When this red light strikes the Moon, it also appears red.
It’s not quite as exciting an explanation as the sky gods being displeased with us, but it’s still cool nonetheless.
The Watch Connection
As you’re no doubt aware, the lunar calendar has been studied since ancient times and formed an integral part of our early understanding of the passage of time. As a result, moon phase complications have featured heavily throughout the history of mechanical watchmaking – so much so that we’re going to be publishing a separate article dedicated to them, so keep an eye out for that.
In the meantime, make sure you’re gazing up at the night sky on February 19th to experience the awe-inspiring beauty of the Super Snow Moon.