Last Saturday we were treated to the closest and largest full moon of this year. Astronomers call this sort of close full moon a “perigee full moon”. The word perigee describes the moon’s closest point to Earth for a given month. But last year, when the closest and largest full moon occurred on March 19, 2011, many used the term “supermoon”, which was once again used to describe this 2012 close full moon. The word supermoon didn’t come from astronomy, but rather from astrology. Astrologer Richard Nolle of the website www.astropro.com takes credit for coining the term “supermoon”. In 1979, he defined it as:
“…a new or full moon which occurs with the moon at or near (within 90% of) its closest approach to Earth in a given orbit (perigee). In short, Earth, moon and sun are all in a line, with moon in its nearest approach to Earth.”
According to Nolle’s definition, he says that:
“There are 4-6 supermoons a year on average.”
Well, what’s all the fuss about, then? Saturday’s close full moon lines up much more closely with perigee (the moon’s closest point to Earth) than Nolle’s original definition. At perigee, the moon lies only 356,955 kilometers away. Later this month, on May 19, the moon will swing out to apogee (its farthest point for the month) at 406,448 kilometers distant.
The moon won’t come as close as this month’s extra-close moon until August 10, 2014. Even the proximity of full moon with perigee in today’s moon isn’t all that rare. Looking further into the future, the perigee full moon on November 14, 2016 (356,509 km) will even be closer than the one on March 19, 2011 (356,575 km). The perigee full moon will come closer than 356,500 kilometers for the first time in the 21st century on November 25, 2034 (356,446 km). The closest moon of the 21st century will fall on December 6, 2052 (356,421 km).
All full moons bring higher-than-usual tides, and perigee full moons bring the highest (and lowest) tides of all. Each month, on the day of the full moon, the moon, Earth and sun are aligned, with Earth in between. This line up creates wide-ranging tides, known as spring tides. High spring tides climb up especially high, and on the same day low tides plunge especially low. Last Saturday’s extra-close full moon accentuated these monthly (full moon) spring tides all the more.
Did you know that each full moon every month has its own name (for Northern Hemisphere):
January: Old Moon, or Moon After Yule
February: Snow Moon, Hunger Moon, or Wolf Moon
March: Sap Moon, Crow Moon, or Lenten Moon
April: Grass Moon, or Egg Moon
May: Planting Moon, or Milk Moon
June: Rose Moon, Flower Moon, or Strawberry Moon
July: Thunder Moon, or Hay Moon
August: Green Corn Moon, or Grain Moon
September: Fruit Moon, or Harvest Moon
October: Harvest Moon, or Hunter’s Moon
November: Hunter’s Moon, Frosty Moon, or Beaver Moon
December: Moon Before Yule, or Long Night Moon
About once every 19 years, February has no full moon at all. Moreover, in 7 out of every 19 years, two full moons will fall in the same calendar month. The second of the month’s two full moons is popularly referred to as a Blue Moon. The next Blue Moon by this definition will happen on August 31, 2012.
I was onder the impression that spring tides had something to do with the spring. So they occur every month?
ReplyDeleteScience doesn't normally excite me but occasionally it does.
ReplyDeleteI wonder why each full moon every month has its own name, but only in the Northern Hemisphere. Does the other half of the globe have different names?
If the second of the month’s two full moons is popularly referred to as a Blue Moon, it gives sense to the often-used expression "once in a blue moon". Meaning a rarity.
Wow! You have gathered lot of info here. Very interesting.
ReplyDeleteI have noted down the names of the moon. Thanks so much.
P.M.D., A Spring tide is that in which the difference between high and low tide is the greatest. Spring tides occur when the Moon is either new or full, and the Sun, the Moon, and the Earth are aligned. When this is the case, their collective gravitational pull on the Earth's water is strengthened. The highest spring tides (equinoctial springs) occur at the equinoxes
ReplyDeleteHels, if you want to use the Northern Hemisphere neo-Pagan names for the Southern Hemisphere full moons, you can calculate what they'll be based upon the timing of the equinoxes and solstices. The autumn equinox is in March, in the southern hemisphere, so the moon nearest that would be the Harvest Moon. The next one, which would fall in April, would be the Hunter's Moon, followed by the Frosty Moon. The next month would be June, which is the time of the Winter Solstice in the southern hemisphere, and corresponds to the Long Nights Moon, and so forth.
You're welcome, Indrani!
Great post, sadly I missed this lunar event, it was cloudy and raining a bit over here. Cool post, and thanks for visiting my blog!
ReplyDeleteIt was, and is, beautiful, isn't it?
ReplyDeleteEven though we missed it, too, here ^^
Good to read you, Nic!
As always,
Lea