Several crop pictures from the summer of 2007 have suggested a near-future date of August 18 for the occurrence of some unexpected event, that may cause Earth's scientists to take the crop-circle phenomenon seriously.

On July 7 at East Field, a series of lunar phase cycles seemed to end anomalously on August 18, just six days after a new Moon. Then on August 1 at Sugar Hill, a series of cube sundials were used to symbolize a time interval of only 18 days, between midnight on July 31 (when that crop picture appeared) and midnight on August 18.

Now on August 4 at Pewsey, we have been presented with a "solar-lunar calendar" that gives precise dates based on motions of the Sun and/or Moon. We need to study it carefully in order to understand what they are telling us:

Lunar phase information

With those ideas in mind, I first calculated a precise value of "lunar phase" as shown in that new crop picture, based on the geometry of its large internal crescent which seems to symbolize the Moon.

Most astronomers define lunar phase in terms of "fractional illumination", or how much of the Moon's surface facing Earth is illuminated by sunlight. We can find fractional illumination from the Pewsey crop picture by measuring the area of a large outer circle (surrounding that crescent), minus the area of a small inner circle (internal to the crescent), then dividing by the area of the large outer circle.

From published photographs, I measured diameter (outer circle) = 123 mm versus diameter (inner circle) = 100 mm. Those values give radius (outer circle) = 61.5 mm versus radius (inner circle) = 50.0 mm. Taking the squares, we find (3782 - 2500) / 3782 = 34% lunar phase. Another photograph gave 32%. Perhaps someone might wish to measure in the field?

Using a program from the web (http://aa.usno.navy.mil/data/docs/AltAz.html), one can determine that a narrow range of lunar phases from 32-34% gives near-future times based on GMT as either August 7 from 0700 to 1200, or else August 18 at 2400 to August 19 at 0600. In light of other recent crop pictures, the latter might seem more relevant than the former:

Solar azimuth information

Next I tried to find out what they were telling us concerning the Sun? As shown the in first diagram above, their solar calendar shows threefold symmetry about the centre. Hence sunrise would lie on the eastern horizon at 60 degrees, noon would lie high in the southern sky at 180 degrees, while sunset would lie on the western horizon at 300 degrees. Another crop picture from Avebury last week likewise showed threefold solar symmetry, on a date of July 31 for latitude 51 degrees North.

But such symmetry depends on latitude, and may be calculated as August 4 (when Pewsey appeared) for latitude 52 degrees, August 7 for latitude 54 degrees, or August 18 for latitude 61 degrees. That final value would correspond to southern Norway, where the ancient inhabitants of Britain (called Tuatha de' Danaan) lived before they migrated to Scotland, Ireland and Avebury. Further crop pictures over the next two weeks will be eagerly anticipated. What next?

An alternative interpretation that gives almost the same times and dates for 32-34% lunar phase. But I remain unsure whether they intended Pewsey to be field oriented or not.

Why was the lunar crescent at Pewsey oriented toward a setting Sun?

Pewsey of August 4 showed a lunar crescent with 34% phase, that could be interpreted either as a waning moon on August 7, or as a growing moon on August 18-19. To resolve that ambiguity, the crop artists oriented it in the field toward a setting Sun. Their culturally-specific symbols often show "a new Moon coming out of the setting Sun" (as at Stonehenge 1996), but never "a full Moon coming out of the rising Sun".

Hence that lunar crescent at Pewsey seemingly refers to the "next new Moon" beginning on August 13, which will reach 32-34% phase after six days. Indeed, that was precisely what they showed at East Field on July 7 for lunar cycle IV.

Red Collie