Retrograde

How the planets get Retrograde :-

The planets including earth move in one direction - anti Clockwise around the sun. When the planet and the earth are on the same side of the sun, the planet seems to be moving in the opposite direction from earth. This motion is called retrogression of planet. The names of different planets according to the Indian and western system and their symbols are as under :-
 

What is Rahu/ Ketu

What is Rahu/ Ketu :-
 
Earth revolves round the sun in a plane called Ecliptic. Moon revolves round the earth in a different plane which intersects ecliptic in a line. The point from where Moon seems to be going up is called Rahu & the point where Moon seems to be going down is called Ketu. These are only imaginary point but have special importance became their position define the eclipse - Solar or lunar. If Moon earth & Sun are in line with Rahu or Ketu an eclipse is formed. Since eclipse plays an important role an earth and in astrology too, Rahu/Ketu are important and are given the status of planets.

Nakshatra

            Nakshatra :-
 
Looking at the daily movement of Moon, sages also identified 27 constellations around the celestial called Ashwini, Bharani etc. They are separated by 360°/27= 13°20'. Every day Moon crosses over one constellation.Start of Ashwini match with the start of first sign 'Aries'. From earth we see a celestial body passing over a sign, this helps us know the location of that body. In astronomy we define planet as a celestial body which revolved round the Sun and a body which revolves around a planet is called a satellite. Sun is termed as a star. In astrology planet is defined differently. Since man lives on earth and we want to studies effect of celestial bodies on human being, we study the motion of celestial bodies with
respect to earth i.e. we take earth in center and measure position of bodies around it, including. Sun, Moon and other planets. To measure the position we take far placed stars as fixed and use them to know the coordinates/position of the other celestial bodies. In astrology we define a planet an any celestial body revolving round the earth; thus Sun & Moon are consider as planets for the purpose of astrology.

Chapter1. ZODIAC, SIGNS AND PLANETS { Celestial System }

 Chapter1. ZODIAC, SIGNS AND PLANETS

Celestial System :-

The mother earth rotates on its axis once in 24 hrs and revolves around the Sun in 365.2422 days. Various planets like Mercury, Venus, Mars, Jupiter & Saturn also revolve around the Sun. These planets have satellites revolving round them. Earth has one satellite called Moon revolving around it. The complete Solar system also revolved around the center of our Galaxy "Milky Way" and makes one round in little hrs than 26000 years. The Galaxy has many solar systems with different Suns at their centers. Galaxy is shaped like two saucers placed one over the other and our solar system is revolving around it on one side of it. As earth revolves around the Sun, we see from earth stars around us in the sky. On account of motion of Earth around the Sun, the Sun appears to move round the stars once in a year. The line along which the Sun moves is called the Ecliptic. The broad band or belt in the heaven extending 90 on either side of the Ecliptic is known as Zodiac. The Ecliptic passes through center of zodiac longitudinally. The zodiac revolves once in a day on its axis from east to west.The zodiac is divided into twelve equal parts, for purpose of astrology, called signs, which are named after the imaginary figures which the stars form in each division. Since zodiac consists of 360°., each sign will consist of 360°/12=30°. The signs are known as Rashis. Our sages identified twelve group of stars separated approx.30° each in the 360° celestial sphere. Thus we have 12 Rashis. They divided the celestial sphere in 12 parts because moon moves around the earth 12 times during the time earth revolved round the Sun.