Planets/ Graha can influence certain degrees of the zodiac from where they are placed. These are called aspects or vision/drushti. You need to know the aspects because they can completely change the results these planets can give in your life. Obviously a planet will give full results in the sign/house that he is placed in. And depending on the strength of the planet in your chart, he can give results as if he is actually placed in the house he aspects.
As per Vedic astrology, these are very limited aspects which a planet can have,
- Every planet (except Rahu/Ketu) aspects the sign/house placed exactly opposite it, 180 degrees away. e.g planets placed in the 1st house will aspect the 7th house of the chart.
- Then Mars has 2 additional aspects – He aspects the fourth and the eighth house from where he is placed. So his aspects are 4th, 7th and 8th house from where he is.
- Jupiter has 2 additional aspects, he aspects the 5th and 9th houses from where he is placed in the chart. So his aspects are 5th, 7th and 9th.
- Saturn has 2 additional aspects – He influences the house 3rd and 10th from where he is placed. So its 3rd, 7th and 10th for Saturn.
These aspects are very easy to remember. The planets inwards from the earth do not have additional aspects, they have just the basic 7th house aspect. The three outer planets Mars, Jupiter and Saturn have additional aspects.
Now for Rahu/Ketu, there are several differing opinions on their ability to aspect, but there are very few actual references from the texts. In my experience, they do not have any aspects. Not even the normal diametrically opposite 7th house aspect. This is because they themselves are diametrically opposite! If there is some planet with Ketu, the correct analysis would be ‘conjoint Ketu’ and not ‘7th aspected by/opposite Rahu’. Ketu doesn’t have a head!, thus no eyes, no vision/drushti! Rahu desires everything except Ketu, he is done with the things that Ketu signifies so doesn’t see him at all! So Rahu cannot have even the 7th house/opposite aspect. These 2 graha/forces sort of merge with the planets they are conjoint with or if placed alone, they give results with the owner of the sign they are in.
- e.g. So if you have a Jupiter+Rahu in the 1st house, Jupiter will take on qualities of Rahu and when he ‘sees’ with his 5th-7th-9th aspects, it will be a composite Jupiter+Rahu ‘seeing’ there.
- e.g. If you have a Ketu sitting alone in Taurus in the 11th house, he will give results as per Venus’s power in the chart and the results will be as per the keywords of the 11th house and Taurus.
The planets when they aspect,
- they influence the houses,
- the signs placed in the houses
- and also other planets if placed in those houses.
If two planets are together in one sign they influence each other if they are less than 15 degrees apart. The planet which is stronger naturally has more influence over the other. If they are more than 15degrees apart but in the same sign they will not influence each other so much but both will influence the sign and house they are placed in.
Now if you get into the western concept of astrology, you are bound to be a bit confused. Semi-sextile, sextile, square, trine, square, quincuncx opposition etc. Semi-Sextile – When two planets are 30 degrees apart. Sextile – When two planets are 60 degrees apart. Square – When two planets are 90 degrees apart. Trine – When two planets are 120 degrees apart. Quincunx – When two planets are 150 degrees away. Opposition – When two planets are 180 degrees apart. I can never remember these and very frankly these others are not true aspects/vision/drushti.
These are basically an extension of the Trikon concept (Dharma, Artha, Kama and Moksh trikon), Bhavat bhavam, Argala, Badhak, etc concepts that we use in Vedic Jyotish. Never learn things by rote, always try to understand why it happens the way it does. Only then you can confidently analyse the interactions of the planets/houses with each other.