Planetary aspects are interchange of energies at great distances; the respective mass of each planet generates and radiates its own specific energy-field. At times these planetary aspects take a lead over planetary conjunctions. Planetary aspects play an important role in predicting future events. However, there are three great differences between Western astrology and Hindu astrology in computing these aspects - (1) in the former system the count is made from degree to degree, in the latter system the count is made from sign to sign, (2) in the former system the aspect will be mutually the same i.e. if Mars and Jupiter are in trine it can be expressed as either Mars Trine Jupiter or Jupiter Trine Mars, in the latter system if Jupiter is in Aries and Mars in Leo, Jupiter will have full aspect on Mars but Mars will have 50% aspect on Jupiter and, (3) in the former system certain aspects such as sextile are good whereas square and opposition are evil, the latter system does not have such classification in which system aspects by benefic planets and those owning trines i.e. the 5th and the 9th, are always good, and by malefic planets and those owning cadent houses i.e. the 6th, 8th or 12th, are always evil; moreover, the aspect of any planet on its own sign strengthens that house and causes no harm to its indications.
Aspects of natural benefics, the Full Moon, Mercury, Venus and Jupiter, are considered to be productive of good results and those by natural malefics, the Sun, Mars and Saturn, evil. Natural benefics owning evil bhavas, combust or in debilitation sign or defeated in planetary-war (graha-yuddha) become tainted and prove contra-productive. Natural malefics owning auspicious bhavas, when they act as yogakarakas, tend to produce good results. These are the basic rules concerning planetary aspects.