Summary: Covers a key component of chart interpretation – assessing the ‘strength’ or ‘power’ of a planet from its sign placement in a birth-chart
In Jyotish, a key component of chart interpretation lies in assessing the ‘strength’ or ‘power’ of a planet.
A planet that is classified as ‘strong’ brings many benefits and signifies positive returning karmas. In general, ‘strong’ equates with ‘good’! The benefits will be in the life areas indicated by the natural associations or indications of that planet (e.g. health, power, self-esteem, relationship with father are natural associations or indicators of the Sun; mind, emotions, memory are associated with the Moon).
A ‘strong’ planet also brings benefits to the signs associated with that particular planet. By ‘association’ we mean sign(s) the planet is said to ‘own or rule’.
For example, as the Sun is said to be the ‘owner or ruler’  of the sign of Leo (sidereal), a strong Sun brings benefits to the house in the birth chart that corresponds with the sign of Leo. It therefore brings benefits to all life areas that specific house indicates. The house number (1 to 12) will depend of course on a person’s ascendant. Note that in Jyotish signs and houses correspond exactly – unlike in some western astrological systems.
Suppose a person had an ascendant in Aries – this sign then becomes the first house and the sign of Leo (counting clockwise from Aries – yes clockwise, unlike in the Western system) would be the 5th house. So, if the Sun was ‘strong’ (by sign placement – see below) the affairs indicated by the 5th house e.g. children, intelligence and education, would also be supported in a positive way. This is in addition to the natural indications of the Sun (health, power, etc.)
Although there are numerous ways of assessing a planet’s strength, a fundamental indication of strength is to assign a particular state (Avastha) depending on the sign of the zodiac in which the planet is located. Sometimes even the sector of the sign (say the first 10 deg.) makes a difference to the level of ‘strength’. In Vedic astrology there are certain signs in which a planet is said to be ‘strong’ or ‘powerful’ and so can deliver benefits, whereas in other signs it is said to be ‘weakened’ so we might expect more challenges, difficulties or negative returning karmas associated with it.
When beginning astrology, we can make quite a good initial observation of a birth-chart simply by first looking to see if each of the nine planets is in one of the four key categories of strength. These are called, ‘exalted’, ‘Moolatrikona’, ‘own house’, ‘debilitated’ (fallen). The state of ‘Moolatrikona’ (no direct English equivalent word) brings benefits somewhere between the best state ‘exalted’ and the good state ‘own house’.
The sign where a planet is weakest (debilitated) is exactly 180° opposite its position of maximum strength (exalted).
Professional astrologers add a number of other states lying between the ‘own house’ and ‘debilitated’ states. These are a bit more complicated for beginners, but these five intermediate states are named as follows: ‘great friends’, ‘friends’, ‘neutral’, ‘enemies’, ‘great enemies’. Good Vedic astrological software will show these states for each planet in a birth-chart.
For a proper chart interpretation we should take these nine detailed levels into account, but when we are starting to look at charts for the first time we can just use the four states: exalted, own, Moolatrikona and debilitated. They give a surprisingly accurate picture of an individual’s returning karmas! If you are in any doubts about the validity of Jyotish check these strength indicators out in the charts of your friends and family.
The sage Parashara quantifies the benefits a planet in each state can bring: Exalted 100%, Moolatrikona 75%, Own House 50%, Friendly sign 25%, Neutral sign 12%, and Fallen/Enemies sign 0%. This gives us a general idea of how the state of a planet affects the good it can do. We don’t have to take the above figures too literally – but they give a good illustration of the concepts.
So, if we take a naturally positive planet such as Venus, if it is in its sign of exaltation Pisces, it will bring tremendous benefits (both to its natural indicators, and also to the two houses associated with the signs it rules – Libra and Taurus; the house numbers linked to these signs will of course depend on the particular ascendant in the birth-chart). However, if Venus is located in its sign of debilitation Virgo, it will bring no benefits whatsoever.
Therefore the same planet can act in very different ways according to its sign placement!
Planetary Strengths or Powers by Sign Placement
Exalted sign: Aries (maximum strength at Aries 10°)
Moolatrikona sign: Leo 0° to 20°
Own sign: Leo 20° to 30°
Debilitated sign: Libra (maximum weakness Libra 10°)
Exalted sign: Taurus 0° to 3°
Moolatrikona sign: Taurus 3° to 30°
Own sign: Cancer
Debilitated sign: Scorpio (maximum weakness at Scorpio 3°)
Exalted sign: Capricorn (maximum strength at Capricorn 28°)
Moolatrikona sign: Aries 0° to 12°
Own signs: Aries 12° to 30° and Scorpio
Debilitated sign: Cancer (maximum weakness at Cancer 28°)
Exalted sign: Virgo 0° to 15° (maximum strength at Virgo 15°)
Moolatrikona sign: Virgo 16° to 20°
Own signs: Virgo 20° to 30° and Gemini
Debilitated sign: Pisces (maximum weakness at Pisces 15°)
Exalted sign: Cancer (maximum strength at Cancer 5°)
Moolatrikona sign: Sagittarius 0° to 10°
Own signs: Sagittarius 10° to 30° and Pisces
Debilitated sign: Capricorn (maximum weakness at Capricorn 5°)
Exalted sign: Pisces (maximum strength at Pisces 27°)
Moolatrikona sign: Libra 0° to 15° and Taurus
Own signs: Taurus 15° to 30° and Libra
Debilitated sign: Virgo (maximum weakness at Virgo 27°)
Exalted sign: Libra (maximum strength at Libra 20°)
Moolatrikona sign: Aquarius 0° to 15°
Own signs: Aquarius 15° to 30° and Capricorn
Debilitated sign: Aries (maximum weakness at Aries 20°)
There are considerable differences of opinion in the ancient texts about the signs where Rahu and Ketu are strong or weak. So the following are quoted using the best sources I have available.
Exalted sign: Taurus
Debilitated sign: Scorpio
Exalted sign: Scorpio
Debilitated sign: Taurus
There are also other factors which influence strength. For example, if the planet appears to be moving backwards against the background of the fixed stars (i.e. ‘retrograde’), if it is very close to the Sun (i.e. ‘combust’), or within about 1 degree of another planet (i.e. involved in ‘planetary war’). A planet’s position in the divisional charts (e.g. the ninth division or ‘marriage’ chart) also affects its overall power. These other influences on planetary strength will be covered in further articles.