Although we often describe cosmic events on a scale involving millions and billions of years, various events involving
our two closest and most visible celestial neighbours, the sun and moon, provide a wide variety of interesting celestial
mechanic variations over the course of a few months and certainly during the twelve months of a calendar year. For
example, the analemma describes the change in azimuth and
altitude of the sun when observed at the same time and from the same location over twelve months. Similarly, the
elliptical orbit of our planet around the sun yields slight changes in the apparent
diameter of the sun.
Similar dynamic changes are also applicable with our moon. Aside from the daily changes in the phase of the moon during one synodic month as well as the change in its apparent diameter when observed during the course of a year, the moon's altitude also exhibits dramatic variations about the ecliptic ranging from a minimum of 36.6 to a maximum of 57.2 degrees. This is directly related to the tilt in earth's axis of rotation by +23.45° in relation to the plane defined by its annual orbit about the sun (ie. the ecliptic) plus a further +5.15° which the moon exhibits in a similar fashion in relation to the same ecliptic.
More specifically, the Saros cycle (6585.3 days or 18 yrs and 11.3 days) defines the period where the geometric alignment between the sun, the earth and the moon can be precisely replicated. Although the Saros cycle was originally used as a means to predict (future and past) eclipses, it has a wide variety of applications given the repeatability of this three-body geometry. As far as the minor and major lunar standstills are concerned, the moon can be observed during a particular year of the Saros cycle (ex. 2006) to have a maximum declination of 28.60° (23.45°+5.15°) above and below the ecliptic during a single synodic month, commonly referred to as the major lunar standstill, and a minimum declination of 18.30° (23.45°-5.15°) above and below the ecliptic during a single synodic month during a different year of the Saros cycle (mid-Saros, ex. 2015), and is commonly referred to as the minor lunar standstill. Furthermore, the month-to-month variations for years characterized with a major or minor lunar standstill are relatively minute, thus allowing for the observation of the event when it is most convenient (vis a vis weather etc).
Note: Each time series involving the rising moon and sun was based on exposures spaced five minutes apart and which were digitally combined with the unfiltered foreground image at sunrise for the final composite photo. The declination of the rising moon was 28.2° and which is illustrated by the dramatic difference between the two time series. For a complete list of dates for the current major lunar standstill where the moon is at the maximum and minimum possible altitude (or declination) during a single synodic month, click here (2006) and/or here (2005-2007).
Note: Please click on the above image to display in a much larger and suitable format (1974 x 509).
Sept 03/15, 2006
Canon EOS 300d
Canon EOS EF-S 18-55 mm
@ 35 mm
Baader ND5.0 Solar Filter
49 x (1/100 - 2 sec)
RAW Image Format
3072x2048 image size
Canon FileViewer V1.3.2
RAW to 16-bit conversion
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