In vedic astrology, 7 planets, 2 shadow planets and the Ascendant are studied and analysed.
The 7 planets are Sun, Moon, Mars, Mercury, Jupiter, Venus and Saturn. Each of these 7 planets has exaltation and debilitation signs. The Sun and the Moon signify the soul and the mind respectively and the other planets refer to the five senses.
The 2 shadow planets mentioned are not actual planets but the invisible north and south nodes of the Moon known as Rahu and Ketu respectively. They are also commonly referred to as the snake planets due to the mythology concerning them. Rahu and Ketu also have exaltation and debilitation signs.
Rahu and Ketu are enemies to the Sun and Moon and they will accordingly cause trouble to the soul and the body by "constricting", "spitting venom" or "giving dry bites". Of all the 9 planets, the shadow planets, Rahu and Ketu, are the most difficult to assess and predict, probably due their silhouette nature.
The Ascendant which is also known as the Lagna, is the sign that rises in the east at the time of birth. It is one of the main reference points from which the horoscope is studied, the other being the Moon.
The Sun, waning Moon, Mars and Saturn are natural malefics while the waxing Moon, Jupiter and Venus are natural benefics. Mercury is neutral in disposition, becoming a malefic when associated with malefic and a benefic when associated with benefic. Rahu and Ketu are first rate natural malefics.
As mentioned, the Sun signifies the soul and the Moon is the mind. Strength, speech and intelligence are indicated by Mars, Mercury and Jupiter respectively. Venus governs comforts while Saturn is the indicator of grief.
From Sun onwards up to Saturn, the colours of the planets are copper-red, white, blood-red, green, yellow, multi-coloured and black. The Sun, Mars and Jupiter are males while the Moon and Venus are females. Both Mercury and Saturn are neutrals.
Of directions, Jupiter and Mercury are strong in the east and Saturn in the west. The Moon and Venus are strong in the north while the Sun and Mars are so in the south. Of the 5 elements, the Sun and Mars govern fire, Moon and Venus rule water and the remaining Mercury, Jupiter and Saturn govern earth, space and air respectively.
Saturn, Mars, Mercury, Jupiter, Venus, Moon and Sun possess natural strength, one being stronger than the other in that order, Saturn being the weakest and the Sun being the strongest.