Post by Chicago Astronomer - Astro Joe on Mar 20, 2006 11:57:02 GMT -6
The Moon to be Higher and Lower in 2006
The Moon's nodes—those two points where the Moon's orbit intersects the ecliptic—are not stationary, but move around the ecliptic. This happens because the Moon's orbit slowly “wobbles.” This wobbling effect is due primarily to the Sun's gravitational pull on the Earth-Moon system and is referred to as the regression of the nodes. Indeed, the nodes advance very slowly westward (“regress”) each month, completing one full circuit of the sky in 18.6 years.
In 2006, this shift will carry the Moon's ascending node through the position of the March equinox (which is located in the constellation Pisces). June 19 will be the exact date when the ascending node crosses the celestial equator. As a result, the Moon will end up being positioned farthest to the north and south of the ecliptic around the border of Taurus and Gemini, and on the other side of the sky in Sagittarius, where (respectively) the ecliptic itself is oriented farthest north and south.
So each month in 2006, when the Moon is passing near the Taurus/Gemini border it will appear to ride unusually high in the sky as it crosses the meridian. Conversely, when the Moon is moving through Sagittarius it will run unusually low. In the table below, are the dates when the Moon will passing through these areas of the sky.
Taurus/Gemini (“Runs High”)
Sagittarius (“Runs Low”)
January 10, 11, 12
January 25, 26, 27
February 7, 8, 9
February 22, 23, 24
March 6FQ , 7, 8
March 21, 22LQ, 23
April 2, 3, 4, 30
April 18, 19, 20
May 1, 2, 27, 28, 29
May 15, 16, 17
June 24, 25NM, 26
June 11FM,12,13
July 21, 22, 23
July 8, 9, 10
August 17, 18, 19
August 4, 5, 6
September 13,14LQ,15
September 1, 2, 3, 28, 29, 30FQ
October 11, 12, 13
October 25, 26, 27
November 7, 8, 9
November 22,23,24
December 5, 6, 7
December 19,20NM, 21
NM = New Moon; FQ = First Quarter; FM = Full Moon; LQ= Last Quarter
Sagittarius (“Runs Low”)
January 10, 11, 12
January 25, 26, 27
February 7, 8, 9
February 22, 23, 24
March 6FQ , 7, 8
March 21, 22LQ, 23
April 2, 3, 4, 30
April 18, 19, 20
May 1, 2, 27, 28, 29
May 15, 16, 17
June 24, 25NM, 26
June 11FM,12,13
July 21, 22, 23
July 8, 9, 10
August 17, 18, 19
August 4, 5, 6
September 13,14LQ,15
September 1, 2, 3, 28, 29, 30FQ
October 11, 12, 13
October 25, 26, 27
November 7, 8, 9
November 22,23,24
December 5, 6, 7
December 19,20NM, 21
NM = New Moon; FQ = First Quarter; FM = Full Moon; LQ= Last Quarter
(courtesy of Space.com)
Full story here: www.space.com/spacewatch/060317_night_sky.html
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I was amazed on how far south the Moon was last fall... #wha#