Uranian astrology is a relatively recent methodological approach to astrology based on teachings of German surveyor/astrologer Alfred Witte (1878–1941), founder of the Hamburg School of Astrology. Witte revived and further developed the use of mathematical midpoints for precise astrological analysis and prediction. He was also an avid independent student of astronomy. Prior to 1970, elements of psychological astrology in Uranian astrology were sparse; however psychological astrology is today integrated. Despite Uranian astrology’s capacity to delineate and predict probabilities with precision, its most seasoned practitioners have verified that other psychological, social, and genetic variables operate in tandem with astrological indicators, and continue to affect how energies will ultimately manifest. In other words, astrology is not fate, but an indicator of probabilities modifiable by free-will choice. Thus, foreseen probable events can be altered by free-will choices, and astrology can be used as an early-warning technique to assist in averting problems. Uranian astrology has unfortunately at times been attached to organizations which abuse it for objectives not related to the advancement of Uranian astrology. Uranian astrology lends itself less readily to being categorized as a form of ‘entertainment’ than do more impressionistic traditional popular astrologies. In his early writings in the 1920s, Witte experimented with numerous historical astrology techniques, including the astrological houses, planetary formulae similar to ‘Arabic parts‘, and planetary rulership systems. His approach to astrology was to verify or deny assumptions by means of observation rather than rely blindly on astrological traditions. Witte also proposed the existence of trans-Neptunian objects, which are considered essential to the practice of Uranian astrology. He truly sought to approach astrology scientifically, but was also a frontier scientist open to exploration of new ideas. Along with extensive midpoint analysis, Uranian Astrology incorporates the use of 16th-harmonic angles/astrological aspects, singled out for their correlation with dynamic energy manifestations. These include the conjunction (0°), opposition (180°), square (90°), semi-square (45°), and sesqui-quadrate (135°), as well as all other multiples of 22.5° angles (67.5, 112.5, 157.5). (See the article on the astrological aspects for more information)
The Transneptunian objects proposed by Witte and Sieggrün are as follows. Cupido is possibly what we now classify as a plutino. Recent astronomical discoveries indicate that there are a number of transneptunian bodies interspersed among these, many with highly eccentric and/or elliptical orbits, and not necessarily validating or invalidating them until further astronomical research is conducted. Some Uranian Astrologers (many of whom have insisted on a much more scientific approach to astrology than do most astrologers) believe that these might possibly be gravitational centers among asteroidal belts rather than actual planets by definition, but have demonstrated through research  starting with Witte’s, around 1920, and continued largely by the Hamburg School of Astrology and the School of Uranische Astrologie, that their effect on earthly affairs is substantial.