By now you’ve heard the excitement surrounding what supposedly will loom large in our sky next week: the February full Snow Supermoon! Wait, didn’t we just have a Supermoon last month? Is this really a “Supermoon” or just more hype? Turns out, this one is the real deal. What makes it a Supermoon?
What Makes February’s Full Moon A Supermoon?
On Tuesday, February 19th at 4:00 a.m. EST, the Moon will arrive at its closest point to the Earth for 2019, known as perigee. It will be 221,681 miles away, which is very close (the closest the Moon can get is 221,429 miles). Then, less than 7 hours later, at 10:54 a.m. EST, the Moon will officially turn 100% full. Because perigee occurs so close to when the Moon turns astronomically full, and the distance to Earth is very close, this Moon certainly earns the Supermoon moniker. Not only will February’s full Moon be the closest to Earth for the year, but it will also be the largest full Moon of 2019 and may appear as much as 14% larger and 30% brighter. So when you watch the Moon rise in the east Tuesday night, it should appear quite large, thanks to a phenomenon known as “Moon illusion.”
Supermoon: An Overused Term?
We seem to hear about Moons being “super” more often than not. The term was first coined by not an astronomer but an astrologer named Richard Nolle back in 1979 who defined it as “a new or full Moon which occurs with the Moon coming to within 90 percent of its closest approach to Earth (perigee).”
That is a rather wide latitude for a full Moon to earn the “Supermoon” title; which is probably why we keep hearing about them, sometimes as often as 3 times per year (you may remember hearing news outlets calling last month’s Wolf Moon eclipse a Supermoon—we did not). To further confuse things, many astronomy sources have their own definitions of what makes a full Moon a Supermoon.
The Farmers’ Almanac Supermoon Definition
Here at the Farmers’ Almanac we are of the opinion that the “Supermoon” title shouldn’t be watered down, and for a full Moon to be truly a Supermoon, it should to come exceptionally close to Earth and coincide with perigee; more like 99% rather than Nolle’s 90%. Astronomers call these perigean full Moons, but that name doesn’t seem to be as easy to remember or as exciting as Supermoon. It’s certainly not as fun to say. But if calling it a Supermoon gets people excited about astronomy, we’re all for it!
So mark your calendars, and here’s hoping for clear skies!