In mid-November our full moon was a “supermoon.” The moon was closer to the Earth than it had been in 70 years, and the truly unexpected feature of this November, 2016 full moon was that we actually see it! Cloudy skies are the rule here in Western Pennsylvania especially during our drizzly, autumn season. The November “supermoon,” though, looked like almost every other full moon that I have seen. I couldn’t say that it was bigger or brighter than normal (the 7% increase in size and the 15% increase in brightness were hard to discern).
A “supermoon” occurs when the moon is at the perigee (closest point) of its elliptical orbit around the Earth and is simultaneously in its full phase. When the moon is full at its apogee (most distant point) it will be 14% smaller and 30% less bright than the perigee “supermoon.” You would need to view these two moons side by side to really appreciate their differences, though (now THAT would be an exciting astronomical (and probably even astrological!) event! If it happened, though, it would probably be too cloudy to see it).
On average the moon is 238,000 miles away from the Earth. At the November 14, 2016 perigee, though, the moon was only 221,524 miles away from the Earth (and at its next apogee on November 27 it was 252,688 miles away. Quite a fluctuation in distance!
Ocean waters rise and fall under the gravitational tugging and pulling of the moon (and the sun!). The twice daily coastal changes in sea level (the tides) are reflective of their oscillating, gravitational influences. When the sun and the moon line up relative to Earth in space their influence on tides increases. At “new moon” the sun and the moon are on the same side of the Earth pulling together, and at “full moon” they are on opposite sides of the Earth having a great tug-of-war on the oceans. Both extremes will cause the tidal movements to be exaggerated. When the moon is at its apogee its influence is decreased and tides will not rise as high (“neap tides”) and the difference between high and low tide will be reduced. When the moon is at its perigee, though, it’s influence will increase and tides will be quite high (“spring tides”) and the differences between high and low tides expanded.
The gravity of the moon (and sun) also tugs and pulls on the Earth’s land masses. The continents themselves move (very slightly) when the gravitational forces are combined or intensified. There is even a slight increase in tectonic activity (earthquakes!) when the sun and the moon line up in their “new moon” and “full moon” configurations.
Many animals (including humans) alter their behaviors as the moon goes through its phases. Many of these described changes can be explained by the increased light of the full moon or the intensified darkness of the new moon. For example, African lions change the timing of their hunting patterns when the moon is full. The lions switch from night hunting to day hunting in response to their prey hunkering down at night to avoid exposing themselves in the over-illuminated savannahs. A consequence of this temporal shift in activity is that the lions now are more likely to encounter humans (and the incidence of lion attacks and human deaths increase!).
European badgers tend to mate during the nights of the new moon. This is because badger mating takes over an hour and a half for full completion. On nights with any moonlight at all the mating badgers (who apparently must really concentrate on the mating task before them!) are increasingly vulnerable to (and oblivious of?) predators.
Corals release massive clouds of sperm and eggs in conjunction with the full moon. Timing this release as total group effort makes the probability of a sperm finding a suitable egg greater and thus increases the reproductive efficiency of the entire population.
The moon, though, may also affect organisms more subtly than simply as serving as a light source. In his 2006 paper published in the on-line Polish medical journal Postepy Hig Med Dosw, M. Zimecki speculates that the gravitational influences of the moon during its waxing and waning cycles may affect the synthesis and release of both hormones and neurotransmitters which in turn alter the functioning of a variety of organ systems (including the immune, the reproductive and the cardiovascular systems) in many types of animals (including humans). In birds, the daily fluctuation in melatonin and corticosterone stops during full moon phases. In insects, the lunar cycle alters hormone synthesis and developmental processes, and in lab rats, sensory systems (especially taste) and pineal gland functions and anatomy change with the phases of the moon. The immune systems of mice are also inhibited during full moon periods.
During full moons both emergency rooms at hospitals and at veterinary clinics see increases in their patient loads. More accidents occur but there are also more cases of angina, heart attacks and strokes. Not all of these changes are attributable to just the increased light in the night sky! Brain activity changes, and more stress hormones and neuropeptides are synthesized. We all go a little “werewolf” whether we know it or not when the moon is full.
Antlions are glorious little insects that are great fun to watch and play with. These insects have larvae that often called “doodlebugs.” Doodlebugs make ingenious funnel-shaped, pitfall traps in sandy soil and hide in a tunnel at the center of the trap waiting for unsuspecting prey (especially ants!) to fall in. Doodlebugs make bigger funnels and wider, deeper holes when the moon is full. And, they even do this when they are locked away in the total darkness of a laboratory! There is something about the moon, and not just the moonlight that is affecting these doodlebugs.
There are some ominously named full moons coming up. The “Cold Moon” of December, the “Wolf Moon” of January, and the “Snow Moon” of February. They will get us through the winter until at last the “Sap Moon” of March brings the rising sugar maple sap of spring (and all of the maple syrup, too!). Hunker down everyone! We’ve got the coming holidays and then our long trek through winter!