On Wednesday, Aug. 30, you will little doubt hear the mainstream media proclaiming that on that night we may have a possibility to witness a “supermoon.” It is a term, or more specifically, a branding, of relatively recent origin. It originated not from astronomy, but astrology; first coined by an astrologer, who arbitrarily defined it as “a full moon which occurs with the moon at or near (inside 90-percent of) its closest approach to Earth in a given orbit (perigee).”
Indeed, at 12 noon ET on that fifth Wednesday of August, the moon will arrive at perigee, its closest point in its orbit relative to Earth at 221,942 miles (357,181 km) away. And 9 hours and 36 minutes later, the moon will officially turn full. Although a full moon theoretically lasts only a moment, that moment is imperceptible to extraordinary commentary, and for a day or so before and after, most will speak of seeing the nearly full moon as “full”: The shaded strip is so narrow, and changing in apparent width so slowly, that it is difficult for the naked eye to inform whether it’s present or which side it’s.
And along with its “supermoon” status, this particular full moon will probably be the second to occur within the month of August, the primary having occurred on Aug. 1. Because of this, the second full moon of August on the thirtieth, will probably be also branded as a “Blue” moon. So, for what it’s value, what we’ll have will probably be a
Nonetheless, unless there may be some unusual atmospheric condition present corresponding to airborne dust, ash or smoke, the moon is not going to appear blue but its normal yellow-white self. Nonetheless, because of mainstream media hyperbole, many will likely sit up for getting a view of this big late summer moon.
Related: Full moon calendar 2023: When to see the following full moon
In the event you are hoping to catch a have a look at the total moon, our guide to the best binoculars could assist you find some nice wide-angle optics for taking in larger areas of the lunar surface. Or, if you desire to take a more in-depth have a look at the features of the moon, our guide to the best telescopes can assist you find the gear you would like.
And in the event you’re seeking to take photos of our natural satellite or the night sky usually, try our guide on how one can photograph the moon, in addition to our best cameras for astrophotography and best lenses for astrophotography.
This flood’s for you
But there may be also a drawback: A full moon nearly coinciding with perigee implies that for several days around Aug. 30, the range of tides will probably be much larger than normal; low tides will probably be unusually low while high tides will run unusually high, even perhaps leading to minor coastal flooding.
Such an extreme tide is often known as a perigean spring tide, the word spring being derived from the German to “spring up,” and just isn’t — as is commonly mistaken — a reference to the spring season. Every month, spring tides occur when the moon is full and latest. At these times the moon and the sun form a line with the Earth, so their tidal effects add together. (The sun exerts a bit lower than half the tidal force of the moon.) “Neap tides,” then again, occur when the moon is at first and last quarter and works at cross-purposes with the sun. At these times tides are weak.
Tidal force varies because the inverse cube of an object’s distance. On Wednesday the moon is 14 percent closer at perigee than at apogee. Due to this fact, it exerts 48 percent more tidal force through the spring tides of Aug. 30 than the spring tides near apogee two weeks earlier on Aug. 16.
And if a big storm or a hurricane is offshore, working in concert with the already high-water levels, the results could lead on to rough seas, beach erosion and major flooding.
We will only hope that such meteorological conditions don’t materialize this yr, though it must be identified that the standard peak of the Atlantic hurricane season comes lower than two weeks later, on Sept. 10.
Supermoon branding “watered down”
For years, astronomers classified a full moon that coincided with perigee as a “perigean full moon.” A term that received little or no fanfare.
Now, plainly each time a full moon coincides with perigee, it’s known as a “supermoon.” Some newscasters — in an apparent effort to carry your attention — seek advice from this occurrence as “rare,” although, essentially, the moon turning full inside hours of it arriving at perigee just isn’t really such a rare occurrence.
In actual fact, on average, it occurs at an interval of once about every 413 days.
After next Wednesday, the following time it will occur will probably be on Oct. 17, 2024.
And yet the total moon of Aug. 1, which occurred about 11 and a half hours before perigee, in addition to next month’s full moon on Sept. 29 which comes nearly 33 hours after perigee, are also being branded as supermoons, seemingly because they fall inside 90-percent of moon’s closest approach to Earth. Or in other words, inside the top 10-percent of the closest full moons for a given yr.
So now in most years we now have not only one but 4 “supermoons.” In some years, there is perhaps as few as two while in other years there may very well be as many as five!
But just how “rare” or “super” is that?
Unrealistic expectations: Greater?
And while Wednesday’s moon will probably be — because the Observer’s Handbook of the Royal Astronomical Society of Canada suggests — the “largest full moon of 2023,” (14% larger in apparent size in comparison with a full moon at apogee — its farthest from Earth) the variation of the moon’s distance just isn’t readily apparent to observers viewing the moon directly.
So, in the event you step outside and have a look at the moon on Wednesday night and expect to see something special, you will likely be disenchanted. There are all the time many images published on the web upfront of a “Supermoon,” displaying exceedingly large full moons, all taken with telephoto lenses, all implying that the moon goes to look amazingly large within the sky.
In actual fact, with no advance knowledge of the closeness of the total moon, it’s likely most individuals wouldn’t notice any difference between Wednesday’s full moon and every other full moon. Nonetheless, once the “supermoon” concept is usually recommended, these same people will step outside, look up and declare that the moon look much larger than normal; just like the way in which the phrase “emperor’s latest clothes” has turn out to be an idiom about logical fallacies.
Brighter?
Then there may be the problem regarding the moon’s brightness. Web sites speak of the “supermoon” appearing “30 percent brighter than other full moons.” But that really corresponds to a of lower than three tenths of a magnitude; so, the moonlight on Wednesday night is not going to be exceptionally brilliant.
Yet, there are likely those that think that they will probably be seeing an exceptionally dazzling full moon that night. In June 2013, a friend of mine told me that she was expecting that yr’s version of the “supermoon” to look ‘radically brighter,’ “Like with those 3-way light bulbs; I assumed it was going to be like turning the moonlight up a notch.”
As an alternative, the moon’s brightness looked no different in comparison with previous nights.
The moon illusion
Wednesday’s moon might still appear enormous, but for a special reason.
When the perigee moon lies near the horizon it will possibly appear absolutely enormous. That’s when the famous “moon illusion” combines with reality to provide a really stunning view. For reasons not fully understood by astronomers or psychologists, a low-hanging moon looks incredibly large when hovering near to trees, buildings and other foreground objects.
The incontrovertible fact that the moon will probably be much closer than usual on Wednesday will only serve to this strange effect.
So, a perigee moon, either rising within the east at sunset or dropping down within the west at sunrise may appear to make the moon appear so close that it almost appears that you could possibly touch it. You possibly can try this out for yourself by first noting the times for moonrise and moonset in your area by going to this U.S. Naval Observatory website.
Don’t overlook Saturn!
A full moon is positioned opposite to the sun within the sky. Because it seems, three days before the moon reaches this point within the sky, the planet Saturn will arrive at opposition to the sun, when it too is opposite to the sun within the sky. So, on Wednesday night, Saturn will “photobomb” the moon, being situated about 5 and a half degrees to its upper right.
Saturn after all is way farther than our nearest neighbor; it is going to be situated 814.6 million miles (1.31 billion km) or 73 light minutes from Earth. The ringed wonder will shine like a sedate yellow-white “star.” The famous rings will probably be tilted 9-degrees toward Earth and are visible in high powered binoculars or small spotting scopes magnifying no less than 25-power.
And so, no matter exactly the way you perceive Wednesday’s full moon, we here at Space.com wish all of you clear, moonlit skies.