The following is a forwarded post from an astrology list that I subscribed to sometime last year (the list has long been inactive, so I forgot I even subscribed). The post here presents some conjecture and some facts that relate directly to the potential uniqueness of what may be a rare example of "perfection" in (solar system) design. As far as earth is concerned, it appears that "cosmic-natural" DESIGN has always been interdisciplinary.
From the Amateur and professional astronomers list (2000.08.30):
Thanks so much for your question about the angle created by the full moon in the sky. This question is much more complicated and interesting than it first appears. Earth may be the only planet in the universe that sports a moon that has an apparent size exactly the same as the sun. This occurs very rarely as the moon changes in size with a 28 day frequency, while the sun changes apparent size every year. Below I cite the day of maximum moon and sun size during the next 12 months:
8JAN01 32' 32"
4JULY01 31' 28"
24JAN01 29' 38'
0.544 degrees of angle
The very remarkable result of this cosmic coincidence is that there are three kinds of solar eclipses depending on the apparent angle of the sun and moon. If the moon is bigger than the sun at that time, there is a dramatic total eclipse that darkens the daytime sky so that there are bright stars seen in the sky. In contrast, if the moon is too small, the sun is never extinguished totally, and in very rare cases they are of equal size. Here a diamond ring of light is seen with a corona decorated by leakage of a single beam of light through the lunar valley at the lim of the moons apparent edge.
A classic total eclipse occurred at 14deg 59min North Latitude 101deg 3min East Longitude on 23 Oct 1995. With the moon at 32' 50" and the sun at 32' 09" we enjoyed a total eclipse lasting 2 minutes and 45 seconds. This location is actually located 9 kilometers north of the center line of the eclipse to avoid light streaming through that canyon at the lim of the moon. This move afforded an extra 9 seconds of totality. With Venus, Saturn and Jupiter in the daytime sky and perfectly clear weather the scene took my breath away. If the moon were just a few miles closer to the earth this cosmically rare scene could never take place. What a remarkable world we live in.....