When two planets are separated by a particular angle, astrologers believe that the influences of the two planets combine to create a strong effect on a person. In ancient astrology and much modern astrology five angles are considered very important: 0, 60, 90, 120, and 180 degrees. These important angles are known as "aspects". In modern times, many astrologers also interpret aspects of 30, 45, 135, and 150 degrees. Some astrologers also use a variety of other angles, such as 72, 144, 40, 80, and many other angles. In the late 20th century a branch of astrology known as "harmonic astrology" developed and practitioners of harmonic astrology believe that there are many hundreds of different aspects, so harmonic astrology has greatly increased the complexity of astrological interpretation.  This report is around 10 pages.