The sky didn’t fall, the floods didn’t come, nor did other catastrophes befall the world last Saturday night.
Pessimists, naysayers and end-of-the-world prophets can go home and recalculate their doomsday predictions for another date (2012 springs to mind). The so-called supermoon that we had on Saturday night, while spectacular, caused no calamities. It did cause many ohhs and ahhs for those of us that observed it.
The term supermoon was coined by astrologer Richard Nolle in the late 1970s, and with the name he offered forecasts of natural disasters, including severe weather, increased seismic activity, tsunamis and volcano eruptions. A supermoon describes a full moon that appears much larger than typical full moons. Supermoons happen when the moon turns full at the sametime it is at the point in its lunarorbit that is closest to the earth.
The lunar orbit — the path that the moon travels around the earth — is an oval, or ellipse. That being so, the moon in its orbitpasses closer to and further from the earth. The closest point in the orbit is called the perigee, while the furthest point is known as the apogee. The average distance between the earth and the moon is about 239,000 miles, but while it is in perigee, it is only 221,565 mile s.
When the moon is closest, it seems 14 per cent bigger and 30 per cent brighter than a typical full moon. It appears the largest as it rises over the horizon, because there are buildings and trees in the foreground to giveit an added illusion of immensity. When itis high overhead, there is nothing similar to compare it to; hence, it looksless mighty against the vastness of the night sky.
Scientists call the phenomenon of a perigee moon a perigee syzygy. Syzygy describes the straight-line order of three celestial bodies — in this case, the straight-line alignment of the sun, earth, and moon that gives us earthlings a view of a full moon. The word syzygy originates from Greek root words meaning “yoked together.”
Though disasters didn’t occur, larger than normal tides can result from a supermoon. Increased tides are called perigean spring tides, though spring refers not in this case to the season, but to the German word “springen,” as in spring up, describing the effect of the perigean tides encroaching onto land.
The last time that we were gifted with this celestial phenomenon was 18 years ago in March of 1993. We won’t have to wait that long for the next supermoon, which is predicted to occur in November of 2016. On the other hand, though, I suspectthat the next occurrence of the full moon in apogee will create far less of a buzz. This will occur this fall on Oct. 11, and the moon will appear 12.3 per cent smaller than normal. But somehow afar-away distant moon just doesn’t capture headlines the way a close-up supermoon does, so it likely won’t be worthy of its own headlines.
For our family, the supermoon was special for more reasons than its infrequency. It might have been partly responsible for shining the way for a miracle emergency plane landing on State Beach and thus protecting some of my family’s most precious cargo.
Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.