Can the Moon really affect our Health?
From sleep and menstrual cycles to full moons and ‘lunacy’, discover the history and science behind the Moon’s supposed effect on humans
Can the Moon affect our health and behaviour?
Royal Museum Greenwich
Sleep trouble. Violent behaviour. Mental health. Menstrual cycles. All these and more have at one time or another been associated with the Moon.
Why have people believed that there is a connection between the Moon and human health? And what, if any, is the scientific basis for it?
How the Moon affects humans – a history
Belief in the Moon’s influence on human sickness and health is ancient and widespread, from early folklore and medicine through to contemporary accounts of full moons and a rise in violent crime.
One of the oldest objects in the 2019 The Moon exhibition at the National Maritime Museum was a Mesopotamian tablet from 172 BCE. The tablet describes how to ward off the evil effects of a lunar eclipse, which were believed to threaten the life of the king.
In ancient Greece and Rome by contrast, girls were given crescent-shaped amulets on their birthday to protect them from evil spirits. Women also wore them to improve fertility and for protection during childbirth.
By the 16th century, tracking the Moon’s position had become an “essential part” of medicine according to Louise Devoy, curator of Royal Observatory Greenwich. The chart below shows one way in which physicians would determine how the Moon affected their patients.
“They used the black spokes on these rotating paper discs – ‘volvelles’ – to keep track of the Moon’s position,” Devoy explains. “The waxing phases of the Moon were thought to enhance the benefits of bloodletting. In contrast, the Full Moon was thought to intensify a patient’s fever. Similarly, apothecaries created herbal remedies using watery plants that were thought to be influenced by the Moon.”
Volvelle to show the critical days of illness, Astronomicum Caesareum by Petrus Apianus, 1540 (ZBA7662, National Maritime Museum)
In Hinduism meanwhile the god Chandra embodies the movement and changing faces of the Moon, and is closely aligned with periods of sickness and health.
In one story, Chandra is cursed by 26 of his wives for spending too much time with the 27th wife. His resulting illness ‘waxes’ and ‘wanes’, echoing the cycle of the Moon.
Animation by TEXTURE
In India, newspapers still report on the belief that people should avoid eating during a lunar eclipse. An article published in the Times of India before the July 2019 eclipse warned, “It is believed that eating during lunar eclipse is harmful for health, and this is simply because the eclipse leads to emission of strong ultraviolet rays, which impacts cooked food as it is prepared with water, which further attracts emissions, which turns the cooked food into poison.”
Lunar cycles and menstrual cycles
There is a long and surprisingly persistent association between the Moon and a woman’s menstrual cycle.
Etymologically at least the connection is clear: the Greek word for Moon – ‘mene’ – and the Latin for month – ‘mensis’ – provide the root for the term ‘menstruation’.
Scientifically, the connection is more dubious.
In 1708, physician Richard Mead published the catchily titled A Discourse concerning the action of the sun and moon on animal bodies and the influence which this may have in many diseases.
Taking inspiration from Isaac Newton’s theories, he proposed that the gravitational pull of the Moon affects fluids within the human body, aggravating conditions such as epilepsy and kidney stones as well as menstrual cycles.
“Every one knows how great a Share the Moon has in forwarding those Evacuations of the weaker Sex, which have their Name from the constant Regularity they keep in their Returns,” he claimed, adding that the Moon’s effect on these “monthly secretions” was more pronounced nearer the Equator.
“It is very observable, that in Countries nearest to the Aequator, where we have proved the Lunar Action to be strongest, these Monthly Secretions are in much greater Quantity than in those near the Poles, where this Force is weakest.”
Diagram of the phases of the Moon, 1846-1860 (AST0051.2, National Maritime Museum)
While there is no scientific evidence to support Mead’s 18th century theories, the ideas that lunar and menstrual cycles can somehow be ‘synced’ has persisted.
In 2016, period tracker app Clue analysed data from over 1.5 million users in order to determine whether there could be a correlation between lunar phases and the menstrual cycle.
The study found no link.
“Looking at the data, we saw that period start dates fall randomly throughout the month, regardless of the lunar phase,” concluded data scientist Dr Marija Vlajic Wheeler.
Does the Moon affect sleep?
The idea that a Full Moon may result in poor sleep is a consistent theme, but the scientific evidence remains inconsistent.
A study in 2013 conducted with 33 volunteers did find that on average it took them five minutes longer to fall asleep during a Full Moon. Volunteers in the experiment also spent 30% less time in deep sleep.
While it’s easy to assume that the increased moonlight from a Full Moon may be the cause of disrupted sleep, this study was held in a sleep laboratory, where the amount of light was tightly regulated each night.
However, following publication of the study, two further experiments failed to replicate the results.
When it comes to the question of whether the Moon affects sleep, the editors of scientific journal Current Biology have this warning: “The conundrum of ‘lunar effects on sleep’ represents an exemplary case of a scientific question which should be approached with caution, as it may seem much easier than it will likely be.”
‘Lunacy’, the Moon and madness
“For millennia, there has been a widespread belief in the association between the Full Moon and extremes of behaviour linked with mental illness,” historian John J. Johnston writes in The Moon exhibition book. “The very word ‘lunatic’, now thankfully outmoded, is an indicator of the former pervasiveness of this conviction among the general public and medical professionals alike.”
Johnston goes on to explain how Aristotle believed that the brain’s high water content made it susceptible to the phases of the Moon. These theories on the ‘tides’ of the mind resulted in a Full Moon becoming associated with violent behaviour, seizures and mental illness.
A buck supermoon is rising on Wednesday. Here’s what to look for
Updated July 13, 202210:08 AM ET
Originally published July 12, 202212:49 PM ET
Malaga, Spain: The full moon is rising over the Malaga lighthouse. The supermoon, also known as the buck moon, will be visible through Friday morning.
SOPA Images/Getty Images
The third supermoon of 2022 will grace the night sky on Wednesday. It’s also known as a uck moon because it falls in July. The name doesn’t come from its appearance — you won’t see the shape of a buck on the moon’s surface or anything. Instead, it refers to something that’s happening in nature.
“The full Moon in July is called the Buck Moon because the antlers of male deer (bucks) are in full-growth mode at this time,” as The Old Farmer’s Almanac says. “Bucks shed and regrow their antlers each year, producing a larger and more impressive set as the years go by.”
What is a supermoon?
What makes this particularbuck moon a supermoon is something else. Supermoons by definition happen “when a full moon coincides with the Moon’s closest approach to Earth in its elliptical orbit, a point known as perigee,” according to NASA.
“During every 27-day orbit around Earth, the Moon reaches both its perigee, about 226,000 miles (363,300 km) from Earth, and its farthest point, or apogee, about 251,000 miles (405,500 km) from Earth.”
Supermoons happen when a full moon comes within at least 90% of the perigee. That happens Wednesday afternoon at 2:38 p.m. ET.
What to look for
Supermoons in general appear 17% bigger and 30% brighter than when the moon is at its farthest point away from Earth, according to NASA. Supermoons are slightly bigger and brighter than most full moons, too. Just because it’s bigger and brighter doesn’t necessarily mean you’ll see it unaided, so binoculars may give you a better view.
And if you’re looking for some photography tips to capture this event, NASA has you covered with these handy tips.
The best times to view the buck moon will be at moonrise and moonset. You can find your local times for those here.
If it’s cloudy where you are on Wednesday, don’t fret too much. The moon will appear full for about three days, through early Friday morning, so there are still viewing opportunities.
And this isn’t the last supermoon of the year either. The sturgeon moon on the night of Aug. 11 will be the final supermoon in this year’s set of four.
Supermoon alert: The biggest full moon of 2022 rises tonight
By Daisy Dobrijevic published about 13 hours ago
The ‘Buck supermoon’ marks the third supermoon in a row.
The full moon of July, also known as the “Buck Moon”, will occur on July 13. (Image credit: Mark Miller Photos via Getty Images)
The largest supermoon of 2022 — July’s full Buck Moon — rises above the eastern horizon tonight.
It will make for a striking skywatching sight as “supermoons shine about 16% brighter and appear 6% larger than an average full moon” writes geophysicist Chris Vaughan, an amateur astronomer with SkySafari Software who oversees Space.com’s Night Sky calendar.
The Buck Moon, also called the Thunder Moon, or Hay Moon, will reach its full phase at 2:38 p.m. EDT or 11:38 a.m. PDT (18:38 GMT), according to Vaughan. It will shine brightly between the constellations of Sagitarrius and Capricornis.
The exact time of the event varies depending on your specific location, so you’ll want to check out a skywatching app like SkySafari or software like Starry Night to check for times. Our picks for the best stargazing apps may help you with your planning.
A full moon occurs when the moon and sun are opposite each other and sunlight strikes the moon face-on. As such, it can be tricky to see features on the lunar surface in detail during a full moon due to the lack of shadows.
and eclipse expert and retired NASA astrophysicist, there are four supermoons in 2022, in May, June, July and August. Espanak’s definition of a supermoon as a full moon within 90% of its closest approach to Earth gives us four to view this year.
July’s full moon is not just an impressive skywatching target but is also an important event in many different cultures worldwide. Here are some examples of the cultural significance of July’s full moon
- Europeans sometimes call this the Hay Moon due to the haymaking season that falls between June and July.
- Hindus, Buddhists, and Jains may call July’s moon the Guru Full Moon (Guru Purnima), “celebrated as a time for clearing the mind and honoring the guru or spiritual master,” NASA said.
- Theravada Buddhists may call July’s moon the Asalha Puha (also known as Dharma Day or Esala Poya — a festival celebrating Buddha’s first sermon, NASA said). July’s moon also marks the beginning of a three-month annual Buddhist retreat called Vassa.
- July’s full moon falls in the middle of the sixth month of the Chinese calendar, Tammuz in the Hebrew calendar and Dhu al-Hijjah — the 12th and final month of the Islamic calendar.
If you’re looking for a telescope or binoculars to observe the moon, our guides for the best binoculars deals and the best telescope deals now can help. Our best cameras for astrophotography and best lenses for astrophotography can also help you prepare to capture the next skywatching sight on your own.
The next full moon will occur on August 11 and is known as the “Sturgeon Moon.” It will also be a supermoon — the final one of the year.
Fancy taking a more in-depth moonlit tour of our rocky companion? Our ultimate guide to observing the moon will help you plan your next skywatching venture whether it be exploring the lunar seas, mountainous terrain, or the many craters that blanket the landscape. You can also see where astronauts, rovers and landers have ventured with our Apollo landing sites observing guide.
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