Mark your calendar for the final full Moon of the millennium --
a last hurrah of unusual brightness.
by Randy Miller
SINCE 1793, when The Old Farmer's Almanac began tracking heavenly events and seasonal changes, the Moon has been full on the first day of winter just nine times. This year, 1999, marks the first time it has happened since 1980. But we have to go back 133 years, to 1866, to match this year's rare gathering of winter solstice, full Moon, and lunar perigee (the point in the Moon's orbit that is closest to Earth).
![The Four Seasons illustration]()
On December 22, 1999, the date of its nearest approach to us, the full Moon will appear measurably larger (about 14 percent) than it does when it's at apogee (the point in its elliptical orbit that is farthest from Earth). Rising just after sunset, this Moon will be close by, high up, and shining at its most brilliant. Since Earth is several million miles closer to the Sun in winter, sunlight striking the Moon is 7 percent stronger. (Perihelion, our closest approach to the Sun, occurs just 12 days later, on January 3, 2000.)
The rarity of a solstitial full Moon -- the average interval is about 19 years -- reinforces the Moon's role as a beacon playing on human history. Although our research could not find a correlation between this lunar event and significant historical happenings on similar dates in the past*, the combination of astronomical forces will certainly affect the tides on December 22. As astronomer Bob Berman explains, "Not only is the Moon at perigee, but it is also the closest one of the year, since the Moon's orbit keeps deforming, and it will be at its most eccentric then. During this time of proxigean tides [unusually high tides due to the Moon's phase and proximity to Earth], coastal flooding could occur if there is one more little extra effect, such as a storm at sea, on-shore winds, or low barometric pressure. The situation is primed for damage."
If the solstice night of December 22 is calm and cloudless, with the full Moon beaming down on a blanket of snow, it will be irresistibly attractive, and electrical illumination -- even your car's headlights -- may seem superfluous. Let's hope for clear weather.
* We did find that on the night of December 21, 1866, the Lakota Sioux staged a devastating retaliatory ambush of soldiers in the Wyoming Territory -- perhaps planning the attack for that bright night, whose lunar confluence was identical to this year's.
Full Moon Occurrences on Solstice and Equinox Dates 1793-2020
| WINTER
| |
| 1809 |
12/21 |
apogee, 22nd |
1828 |
12/21 |
|
1866 |
12/21 |
perigee, 21st |
1885 |
12/21 |
perigee, 22nd |
1904 |
12/22 |
|
1942 |
12/22 |
apogee, 23rd |
1961 |
12/21 |
|
1980 |
12/21 |
|
1999 |
12/22 |
perigee, 22nd |
2010 |
12/21 |
|
| SPRING
| |
1829 |
3/20 |
|
1867 |
3/20 |
|
1924 |
3/20 |
|
1943 |
3/21 |
|
1981 |
3/20 |
|
2019 |
3/20 |
|
| SUMMER
| |
1796 |
6/20 |
apogee, 19th |
1834 |
6/21 |
|
1853 |
6/21 |
|
1910 |
6/22 |
|
1929 |
6/21 |
|
1948 |
6/21 |
|
1986 |
6/21 |
perigee, 21st |
2016 |
6/20 |
|
| AUTUMN
| |
1809 |
9/23 |
|
1820 |
9/22 |
perigee, 21st |
1839 |
9/23 |
perigee, 24th |
1877 |
9/22 |
|
1915 |
9/23 |
|
1991 |
9/23 |
|
|
|
|
|
|
|
Compiled from The Old Farmer's Almanac and Astronomical Tables of the Sun, Moon, and Planets, by Jean Meeus (Willmann-Bell, 1995). The dates are for the Eastern Standard Time zone; Daylight Saving Time has been taken into account for the war years of 1917 and 1942-1945, and from April 1, 1967, onward. Also, dates for lunar perigee and apogee have been included where these fall on or near the full Moon.
Preview to the 2000 Almanac: How to Hypnotize a Chicken, Woolly Bears, The Astonishing Lunar Illumination, Sunspots, Decorative Engravings in the The Old Farmer's Almanac. Part I: Title Page or Frontispiece, Part II: Right-Hand Calendar Pages, Part III: Front Cover.
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