Many people asks questions like what will be the result when Ketu from 4th house aspects Saturn in 10th house? Rahu in Lagna aspects 7th house?. But all these questions are meaningless, because Rahu and Ketu don't have aspects.

Aspect is nothing but the effects of a planet in other house. Jupiter has 5th, 7th, and 9th aspects, Saturn has 3rd, 7th, and 10th aspects, Mars has 4th, 7th, and 8th aspects, and Sun, Moon, Venus, Mercury has 7th aspects only. These are the major aspects and all these planets has other minor aspects also.

Generally, aspects of planets are closely related to their size. Bigger planets are having many aspects while the smaller planets are having few aspects like 7th.

Rahu and Ketu are like empty dark points in the space denoting north and south node of Moon's and Sun's orbits intersections around our Earth. It is like a black hole attracting all the bodies around it. It is said that even light cannot escape from black holes because of its gravity.

As it is an empty dark point, it attracts the luminesence of Moon and Sun and creates Grahan Dosha for them. Then how it can aspect another house when it is not even a planet?

Similarly, Rahu and Ketu not only affects Sun and Moon, it also affects Lagna and other planets. It is seen in Vedic Astrology that several negative yogas where formed when Rahu and Ketu sits in next and previous houses of Lagna and Moon sign. It means Rahu and Ketu also destroys the positive effects of planets in adjacent houses.