Yarn of the Solar System
Assume that the sky is divided into 360 degrees around the earth. All celestial bodies rise in the east of the horizon of Earth and sets in the west just as the Sun (Surya) and the Moon (Chandra).
Zodiac Sign or Rasi Mandal
Stars or Nakshatras are grouped into 12 signs or rasis/rashis. Each sign or rasi contains 2-1/4 stars (constellation) each. Each star or nakshatra consists of four padas, so each sign or rasi consists of (4+4+1) nine padas or navamsas or divisions). The twelve signs or rasis are named Aries or Mesha, Taurus or Vrishabha, Gemini or Mithuna, Cancer or Kartaka, Leo or Simha, Virgo or Kanya, Libra or Thula, Scorpio or Vrischika, Sagittarius or Dhanus, Capricorn or Makara, Aquarius or Kumbha and Pisces or Meena.
House Cusps or Bhava Madhya
- Ascendant (Lagna) / 1st house cusp – the degree of the sky (superimposed on a navamsa or division of a sign) that rises on the horizon in the east at a particular point in time (birth time).
- Descendant / 7th house cusp – the degree (identical to Ascendant) of the sky (superimposed on a navamsa or division of a sign) that sets in the west at 180 degrees from the Ascendant at the same time.
- Mid-heaven / 10th house cusp – a degree identical to that of the Ascendant (superimposed on a navamsa or division of a sign) at 90 degrees to the Ascendant – Descendant axis, overhead, at the same time.
- 4th house cusp – a degree identical to that of the Ascendant (superimposed on a navamsa or division of a sign) at 270 degrees to the Ascendant – Descendant axis, in the opposite direction of the 10th house cusp / Mid-heaven, at the same time.
Houses or Bhavas
Assuming, the sky is again divided into 12 houses or bhavas, 30 degrees each, with a degree identical to the Ascendant at the cusp (bhava madhya or midpoint) of the house or bhava, the 12 houses or bhavas are superimposed on the 12 signs or rasis.
Planets or Grahas
According to Vedic Astrology, there are nine planets or Grahas that revolve around the Sun (Surya) inclusive. Those are Sun (Surya), Moon (Chandra), Mercury (Budha), Venus (Shukra), Mars (Kuja or Mangal), Jupiter (Guru or Brihaspathi), Saturn (Shani), North Node (Rahu) and South Node (Ketu).
These are the position or placement of a planet or graha at a particular degree in a sign or rasi / house or bhava at a particular point in time (for instance birth time).
Sign Lord/Rasiadhipathi or House Lord/Bhavadhipathi
Each sign or rasi is owned or ruled by a particular planet (Lord) based on the nature of the planet similar to that of the rasi. Sign Lord and House Lord are used interchangeably as the Houses are superimposed on Rasis.
House Lords/Bhava Lords/Sign Lords
||Rasi/Sign or Bhava/House Lord
|Mesha/Aries and Vrischika/Scorpio
||Kuja or Mars
|Vrishabha/Taurus and Thula/Libra
||Shukra or Venus
|Mithuna/Gemini and Kanya/Virgo
||Budha or Mercury
||Chandra or Moon
||Surya or Sun
|Dhanus/Sagittarius or Meena/Pisces
||Guru or Jupiter
|Kumbha/Aquarius or Makara/Capricorn
||Shani or Saturn