Earthsky Tonight
What’s special about the Harvest Moon?
09-30-2009 - Astronomy Essentials
Why is the Harvest Moon special?
It’s more than just a connection to the season of harvest. In fact, nature is particularly cooperative during the months of autumn to make the Harvest Moon unique.
Here’s what happens. On average, the moon rises about 50 minutes later each day. But near the time of the autumnal equinox, the moon rises only about 30 minutes later each day. Why? The reason is that the ecliptic – or path of the sun, moon and planets – makes a narrow angle with the evening horizon during the autumn months. The narrow angle of the ecliptic in on autumn evenings results in a shorter-than-usual rising time between successive moonrises around the time of the autumn full moons.
These moonrises are what make every Harvest Moon special. Every full moon rises around the time of sunset. Around the time of this full moon in autumn, you’ll see the moon ascending in the east close to the time of sunset for several evenings in a row. There’s a short time between successive moonrises as described in the paragraph above. Because of this, it seem as if there are several full moons – for several nights in a row – around the time of the Harvest Moon.
Want to know the time of moonrise in your location? My favorite source of that information is this Custom Sunrise Sunset Calendar. Once you get to that page, be sure to click the box for ‘moon phases’ and ‘moonrise and moonset times.’
Is the Harvest Moon bigger, or brighter or more colorful?
No. The Harvest Moon has the reputation of being especially big and bright and orange. But it isn’t really. It’s no bigger, brighter or oranger than any full moon.
Still, you might think it is. That’s because the Harvest Moon has such a powerful mystique. Many people look for the it shortly after sunset around the time of full moon. And after sunset around any full moon, the moon will always be near the horizon – it’ll just have risen. It’s the location of the moon near the horizon that causes the Harvest Moon – or any full moon – to look particularly big and particularly orange in color.
The orange color of a moon near the horizon is a true physical effect. It stems from the fact that – when you look toward the horizon – you are looking through a greater thickness of Earth’s atmosphere than when you gaze up and overhead. The atmosphere scatters blue light – that’s why the sky looks blue. The greater thickness of atmosphere in the direction of a horizon scatters blue light most effectively, but it lets red light pass through to your eyes. So a moon near the horizon takes on a yellow or orange or reddish hue.
The bigger-than-usual size of a moon seen near the horizon is something else entirely. It’s a trick that your eyes are playing – an illusion – called the Moon Illusion. You can lengthy explanations of the Moon Illusion by googling those words yourself.
How the Harvest Moon got its name
So why is this moon – the moon closest to the autumnal equinox – called the Harvest Moon?
The shorter-than-usual time between moonrises around Harvest Moon time means there is no long period of darkness between sunset and moonrise. In the days before tractor lights, the light of the autumn full moon helped farmers bringing in their crops. As the sun’s light faded in the west, the full moon would rise in the east to illuminate the fields for several more hours of work.
Who named the Harvest Moon? That name probably sprang to the lips of farmers throughout the northern hemisphere, on autumn evenings, as the autumn full moon aided in bringing in the crops. The name was popularized in the early 20th century by the song below.
_Shine On Harvest Moon_
_By Nora Bayes and Jack Norworth (1903)_
_Shine on, shine on harvest moon_
_Up in the sky,_
_I ain’t had no lovin’_
_Since January, February, June or July_
_Snow time ain’t no time to stay_
_Outdoors and spoon,_
_So shine on, shine on harvest moon,_
_For me and my gal._
Related:
When will we see the Harvest Moon in 2009?
In 2009, the legendary Harvest Moon …
I like to be able to read short informative bits as this above. Topics such as these help me appreciate my surroundings. Thank you for sharing!
I am way too thrilled to see this!
Interesting! I’ll appreciate the moonrise especially so over the next few days!
yeah so am i isnt it wonder ful
Astrologically (in addition to astronomically) speaking, this Full Moon will occur in the sign of Aries adding mystic to the firey-orange glow of the moon. So much is happening in our skys during this time. Last night our family looked at the near-full moon as well as the moons of Jupiter through my telescope.
Galen,
You’re quite right. The 2009 Full Harvest Moon will occur in the sign of Aries. Yet, this full moon will shine in front of the constellation Pisces.
Bruce
Deborah has captured this quite well. The idea of the Harvest Moon has nothing to do with the color, as the orange color due to Earth’s atmosphere, is just as likely with any other Full Moon. Nor does it have to do with the sometimes supposedly larger size, because although Full Moons due vary slightly in size through the year, the Harvest Moon can no more claim the title of largest Moon than another other Moon through the year, on the average.
Instead, it has to do with the shortened time between moonrises as Deborah Byrd has explained, a real and physical phenomenon, as well as the fame of this phase which makes it more likely that people will look for it. The mystique, built up over the years, enhances the awareness and more people go out to look.
The names of the Full Moons through the year, including the names given by various cultures, not least of which were American Indians (whose names for the 10th full moon of the year — which this one is — included the “Blackberry Moon,” “Turkeys Moon,” and “Falling Leaves Moon”), were made by many cultures. Typically they were related more to local weather patterns or conitions than to astrological predictions or supposed connections between sky events and the human condition.
There being absolutely no physical connection between human behavior or personality to the positions of celestial bodies, the names of the Full Moons through the year represent the coincidental connection of cyclical astronomical phenomena with (mostly) seasonal changes. As such they were important symbols and familiar “landmarks” in the heavens that people could use to relate the passage of time while at the same time enriching their culture. Too bad that we have largely forgotten this real and important societal connection to the heavens, and have instead substituted so many artificial and disconnected connotations to it, if any at all.
As above so below of course there is an effect on our bodies what happens in the heavens or is all around you!
Tonight’s waxing-towards-full Harvest Moon is especially beautiful! Background info is great. I would only suggest that every human female knows there’s gotta be some physical connection to our nearest celestial body, in that it’s no co-inkidink that our menses and the moon’s cycle are both 27.8 days! Kinda weird when you think about it!
Tawhiyda,
There is absolutely no evidence that astronomical happenings (including the Harvest Moon or any phase of the Moon, the positions of planets or stars or in fact anything short of a collision or nearby supernova) has any direct effect on day to day life on Earth or our bodies. Zero, zip, zilch, nada, nihilo — no evidence whatsoever. The only possible or even conceivable influence that the Moon could exert physically on the human body is via the variations in its gravitational pull. You may want to use the analogy of the tides. However — and it is a very big “HOWEVER” — the force of gravity simply has no measurable effect on the human body.
Think of it like this — the entire planet Earth (every continent, every mountain, ever drop of water in the all the oceans and every thing on the planet and inside it) is pulling on you right now, through gravity. Do you feel it? Of course you do. It is simply your own weight. Let’s say, for argument, that you weigh 150 pounds. We know that the Moon’s mass is about 1/81 the mass of the Earth. Total mass is what controls the total amount of gravitational force, so we can say that the Moon’s gravitational force, in total, is only 1/81 that of Earth. Thinking like that, you might think that the force of gravity you experience from the Moon is just under two pounds. That might be significant, but it isn’t right. the force of gravity you experience is determined by how far away you are from the source of gravity. Now it so happens that the Moon is roughly 60 times farther from you at any given time than you are from the source point for measuring your own weight, which is the center of the Earth. If you apply these facts to the Law of Gravitation, you will find that the gravity you “feel” from the Moon is roughly 300,000 times smaller than the gravity you feel from Earth. If you are 150 pounds in weight, then here on the surface of the Earth, the Moon would be pulling at you with about 5 ten thousandths of a pound force, which is roughly one tenth the mass (weight) of a penny. Not only is this imperceptible, it is far less than the many, many gravitations equivalent accelerations you experience every day in walking, using stairs, driving in a car, or in just standing up. Unless you claim that those actions have some kind of special determining or significant affect on our bodies, it certainly makes no sense to believe that the Moon does. Now as for psychological effects… that may be a different story!
stari-eyed,
You may be correct about that, as it has been claimed for a long time, but if so, it likely is the result of evolutionary changes millions of years ago relating to our ancestors who lived near oceans and indirectly experienced effects of the actual oceans tides (rather than direct influence from the Moon), or due to the actual changes in light due to the phases. In either event it was not a direct physical effect of the Moon.
when does the harvest moon set in georgia tonite
Those who claim ’scientific’ knowledge certainties, can say what cannot be “measured” with sufficient evidence that they chose to limit or to define as “valid” or how valid. Those who have more than what science says we are or we can do, wonder why some, not all, scientists are so rigid in their thinking, their explorations beyond their instruments, their misc. studies that may not be repeated with same results, and their arrogance thinking only they know-it-all and there is nothing more to know or be.
Full moon effects may not be felt or experienced by everyone in the same way.
Many peoples for eons have stated they experience differences with different cycles, and in not always instrument-technology-proved-ways with moon phases… [ and not imagined, not commercialized, not insisted they had the only 'last word' on every phenomena either ].
The skeptics could be more Open Minded and Open bodied to recognize that what is published, what is expert-agreed-upon is much more limited than what is actual, what is recognized, and what is not 100% any how.
Try wondering instead of just denying and playing the authority, and find the moon and each life lived to much more magical, unmeasurable, and thus not scientifically provable, even at .05
significance. Hypothesis are just that. Each new “dis-covery” proves that old authority was wrong, again.
Moon is more than just an ‘object’ with no effects except those limited to oceans and gravity. Check out someone else’s experiences and body to find that the mostly male demand to be Right, the only Right one, can also be disproved, scientifically too.
This moon provides more than light to the eyes, for those who can see beyond their body visuals.
Some do. Some dont. Some live more fully, some more strictly and want to put others in that same limited box.
Moon, shine on and produce the effects that also affect, even if some refuse your powers !
maybe it’s more a woman’s thing ? hmmm
Larry, I have to say that I agree with Stari-eyed and with Maryjanie. Just because science hasn\’t found the connection between cycles of the moon and cycles of women\’s bodies doesn\’t mean this connection doesn\’t exist.
It\’s not a gravitational connection, as you say. That much we know. But we don\’t know everything.
As women, we know and feel these cycles. A related phenomenon is that of women living in close proximity whose menstrual cycles begin to coincide. All women know about this, but there was no scientific evidence for it either for all of human existence – until 1971, when it was first described by researcher Martha McClintock, now with the University of Chicago. Now this phenomenon is part of science. It\’s called \”synchronous menstruation.\” It\’s believed to be driven by scent. Here\’s more about it: http://www.straightdope.com/columns/read/532/do-the-menstrual-cycles-of-women-living-together-tend-to-synchronize
Likewise, women have known for all time that their bodies are in alignment with the moon. Many women note a particular moon phase that coincides with the start of their cycle. Women living in tribes, for example – who spent their \’moon-time\’ together in \’moon lodges\’ – must have had the greatest awareness and reinforcement of this powerful and dare I say sacred connection.
Deborah
I must agree with you Debbie. Simply because knowledge falls outside the realm of the male-dominated European model does not negate it’s reality. Indigenous cultures understood pairing certain foods unlocked nutrients and incrased their chances of survival without supporting studies.
Deborah, Stari-eyed, Maryjanie and all:
I did not say that a connection between the human menstrual cycle and the lunar cycle does not exist. But considering that lack of any real evidence that it has anything whatsoever to do with physics, and there being no outstanding reason to hypothesize new and otherwise completely unknown laws of physics, I feel that this is due more to connections in the brain than between human flesh and blood and a huge ball of rock a quarter of a million miles away.
On the other hand, I do not know. I and many others could be wrong. I do not claim to be an authority or expert in this, nor obviously have I ever personally experienced what many women claim to be a connection. Some day a physical connection may be established. But after hundreds of years of intense studies of the known forces of nature, science has not discovered any force that can reasonably serve as a mechanism for this.
Did I deny the importance of mystery and wonder? Certainly not. Without them there would be no curiosity, no research, no progress. Mystery and wonder are what lead to discoveries and the advancement of both science and everyday life. But science demands evidence, and that we follow the evidence in the direction it points. In this case, the evidence points to the human mind rather than physics. This certainly does not diminish the mystery and wonder, but makes it more personal. It focuses the attention on the person rather than on supposed influences from the heavens.
Actually, the notion that women have 28-day menstrual cycles is itself a myth. A normal menstrual cycle can be anywhere from about 21 to 40 days. (Some folks would even argue that this false standardization of women’s cycles is itself a symptom of too much masculine/Cartesian thinking.) So some women, who happen to have 28-day cycles, may notice that their cycles correspond to certain phases of the moon–that is largely coincidence, even though the sense of wonder that it inspires is not, I think, misplaced. But other women, with longer or shorter cycles, will notice no correlation between their periods and the phases of the moon.
S.D., ‘myth’ is a bit strong, I think. It’s my understanding that most women of child-bearing age do have cycles of around 28 days, although there’s nothing abnormal if the cycle is slightly shorter or longer.
I know that teens and older women tend to have more irregular menses, as the cycles establish or begin to diminish – with young girls and senior women having no cycle at all.
I’d be curious to see the actual data related to women aged, say, 20 to 40.
My wife Alice and I enjoyed an animated conversation on whether women’s cycles are linked to those of the moon. Alice is sympathetic to the notion of a lunar phase/menstrual cycle connection while I question the coincidence. If the menstrual cycle is tied to the phases of the moon, why do menstrual periods vary among the primates? Despite irregularities, it’s my understanding that the average human menstrual cycle lasts for about 28 days. Why, then, would the onset of menstruation necessarily align with a particular phase over an extended period of time, given that the lunar phase cycle is about 29.5 days long?
Deborah, the best explanation I have seen for the hows and whys of menstrual cycle variation is in Toni Weschler’s book Taking Charge of Your Fertility (I know that title might sound off-puttingly how-to, but there really is a lot of good basic biology in there). Weschler cites normal menstrual cycle length as 24-36 days (my earlier reference to 21 to 40 was from Natalie Angier’s Woman: An Intimate Geography). The frequently cited statistic that the average menstrual cycle is 28 days is, as I understand it, a population-level statistic, that doesn’t tell us anything about the distribution of cycle lengths around that average. Even if it is a somewhat bell-shaped curve (which, I suspect, it is), that leaves a lot of women–most, even–who *don’t* have 28-day cycles. Sadly, Weschler’s book doesn’t give a frequency distribution of cycle lengths either. A cursory search turned up this paper from 2000:
http://www.bmj.com/cgi/content/full/321/7271/1259?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=ovulation&andorexactfulltext=and&searchid=1104329510069_5743&stored_search=&FIRSTINDEX=0&sortspec=relevance&resourcetype=1
Which addresses timing of ovulation, not menstrual cycle length, but is nevertheless somewhat illuminating. They do show a bell-shaped curve, but of 696 menstrual cycles tracked in their study only 69 of them were 28 days long.
Wow, I bet you never thought your post on the harvest moon would end up here!
Hi S.D., thanks! No, I did not think it’d end up here, but this is an interesting discussion! Thank you for your input.
Deborah,
No, I’m not arguing against the link between women’s cycles and those of the moon. I’m simply asking a few questions. The moon has many differnt cycles. If we wish to link the human menstrual cycle to the moon’s orbital period of 27.3 days – rather than the 29.5-day moon phase cycle – then obviously we have a closer correlation between the periods of these two cycles. But how do we know if this a coincidence or a physical relationship?
Bruce, we don’t know and – odds are – won’t know in our lifetimes. If it is a coincidence, it’s a lovely and poetic one. If it’s not a coincidence, then perhaps someday there will be human beings on Earth who understand it, just as we today understand things about the universe that the Greeks, say, did not. Until such a time, many women – like Alice and me – will continue to believe it because our own bodies seem to say so powerfully that it must be true.
Deborah, I agree: If it’s a coincidence, it’s a lovely and poetic one. Well put!
Bruce
I wonder if what\’s happening on this page is that women are arguing there is a link between their cycles and the moon … while men are arguing against it. S.D. … tell us … are you male or female? Just curious.
Anyway, Bruce, you\’re right that the time between two full moons (and between successive occurrences of the same phase) is about 29.5 days. But, as we both know, the moon makes one orbit of Earth with respect to the stars in 27.3 days. I’m just trying to say that – as we’ve already established – no one really understands the link between women’s cycles and the moon’s cycles, if such a link really does exist. No one knows the subtleties that might be involved. So the argument that it can’t exist due to one cycle of the moon (but not another) isn’t all that strong an argument. IMHO.
let\’s just relish the thought of having a menstrual cycle responding to the pull of the moon. if we were not so bombarded by other energetic pulls on this planet and people spent more time outdoors, maybe we would return to the natural rhythm of the earth and our cosmos.
relax and enjoy the moon!!
Indeed sisters!
For the record, I have never denied that there is a link, but I am saying that the link is psychosomatic rather than physical. And don\’t think I am downplaying it or misusing the term \”psychosomatic.\” I just mean that it is a result of body-mind interaction rather than a physical interaction with the Moon. I don\’t see the need to hypothesize mysterious or even mystical connections when there is no real (by which I mean scientifically acceptable) evidence. Such a connection *may* exist, but there is certainly no evidence of it at this point, and for my money there is no reason to expect it. The mind is a wonderful thing, and wonderfully mysterious in its own right. I feel that we ultimately will find the answer to this question there, and not on the Moon.
Some people feel the 13-month lunar calendar used in olden times better coordinated moon and female cycles with the solar year. Each month had 28 days, giving a lunar year of 364 days (13 x 28 = 364). The 365th day was called “a year and a day.”
people in my area are taking their angle brooms and standing them in the middle of the kitchen and they will stand there for hours. Does any one know if this is always possable or just while the moon is in certain alignment
Hi k.a.b., I think it’s possible at any time. Or not possible. Depending on how well you can balance things!
There was a rumor awhile back that you could balance eggs on their ends only at the equinox. This also proved to be untrue.
Best to you,
Deborah