On the first day of 2018, at 5 p.m. EST, the Moon will arrive at its closest point to the Earth since 1998 — an extreme perigee distance of 221,559 miles away. Then, 4 hours and 24 minutes later, the Moon will officially turn full. When the Moon’s full phase coincides with lunar perigee (its closest point to Earth in its orbit), we have what many refer to as a “supermoon” — known for being bigger and brighter than an average full Moon.
The Largest Full Moon of 2018
While January’s full Moon — named the Wolf Moon — will be the “biggest full Moon of 2018” (the difference in its apparent size to the eye measures just 7.3-percent larger compared to its average distance from Earth), the variation of the Moon’s distance is not readily apparent to observers viewing the Moon directly; put another way, you probably won’t notice much difference.
Of course, once somebody is told that the Moon is closer-than-normal to Earth and consequently appears somewhat larger in apparent size, they may notice a larger Moon. This is especially true if one sees the Moon near the horizon, where the enigmatic “Moon illusion” always comes into play.
The popular astrophysicist, Dr. Neil deGrasse Tyson, probably said it best: “In the overall scheme of things, is this relatively small increase in the Moon’s apparent size really so meaningful? I mean, if you turned a 14-inch pizza into a 15-inch pizza, would you then call it a “Super-pizza?”
Maybe, when it comes to our natural satellite, size doesn’t really matter after all.
Will Ocean Tides Be Affected?
In addition, because this New Year’s full Moon coincides so closely with perigee, it will result in a dramatically large range of high and low ocean tides. Such an extreme tide is known as a perigean spring tide, with the word spring being derived from the German springen — to “spring up,” — not a reference to the spring season.
Whether or not you get excited about this first full Moon of the new year, look for it to rise at around sunset and set at sunrise. As always, we welcome your photos, which you can share with us on our Facebook page.
More “Full Moon Madness” Coming…
There are many more interesting Moon events happening in 2018. First, the Wolf Moon is not the only full Moon we’ll have this month. On January 31st we’ll have a second full Moon (called a “Blue Moon”) along with a total lunar eclipse. This will be followed by a no-Moon February, and another double-full-Moon month in March. Can’t keep track of it all? Don’t worry — we’ll keep you up-to-date on all the details.