Planets and cosmic energies have an effect on human beings and different aspects of human life. In Hindu religion these planetary influences and effect of cosmic energies are shown through the horoscope. Horoscope can be called a detailed layout of the planetary configurations and universal framework which is prepared on the basis of mathematical calculations. It is a simplified map of the Zodiac over a specific location on the Earth at a particular moment in time. Horoscope is the most important astrological concept which has a strong astronomical base. It can be said that astrology is entirely based on this astrological concept of horoscope. Everyone knows that Horoscope is prepared after certain mathematical calculations but it has a strong astronomical base also. Let us discuss in detail about these astronomical facts in detail. Celestial Sphere Celestial Sphere and the framework of different great circles in this sphere form astronomical base for the formation of horoscope. Celestial Sphere is the imaginary sphere which surrounds the Earth. Earth rotates on is axis within this Celestial Sphere but it appears as though the Celestial Sphere is rotating on the same axis as that of the Earth There are four great circles in the Celestial Sphere which are crucial in the formation of horoscope. These great circles are:- Celestial Equator, Celestial Meridian Celestial Horizon Celestial Prime Meridian All these great circles divide the Celestial Sphere into two equal parts and centers of all these great circles align with the centre of the Celestial Sphere itself. The framework of these great circles from the viewpoint of the observer standing on the Celestial Horizon forms the astronomical base for the figure of the horoscope. In other words the diagram of the horoscope depicts the framework created by these great circles in the Celestial sphere. Various important points of the horoscope like ascendant, descendant, MC, IC etc are decided on the basis of the intersections of these great circles in the celestial sphere. As we are discussing the astronomical base of horoscope it is essential to mention here that in most of the applications geocentric perspective is followed. Geocentric means we observe the sky as it looks nor as it is. In this system the observer is the centre point inside the Celestial Sphere. Exactly above the head of the observer is Zenith and directly below his feet is Nadir. Both of these points are on the Celestial Sphere. Zenith and Nadir are the poles of the great circle Horizon on the celestial Sphere. Horizon divides Celestial Sphere into two equal parts visible half and invisible half. This is the platform where observer perceives while looking at Celestial phenomenon. Observer is located at the centre of the Horizon. This Horizon is very important reference level for the horoscope formation. Horizon represents the ascendant and descendant axis in the horoscope. Celestial bodies which are above this ascendant and descend axis are visible and celestial bodies which are below this axis are invisible at the time of birth. On the vertical line we get orientation of Zenith and Nadir. All points at the horizon are 90 degree from Zenith. Celestial Meridian is the great circle which is drawn around the Celestial Sphere from the North point via Zenith, South point and Nadir. It divides the Celestial Sphere into Eastern and Western hemisphere and forms the base for Meridian axis in the horoscope. All Celestial bodies in the Western hemisphere are descending and all celestial bodies at the Eastern hemisphere are ascending. The vertical great circle results from joining the East point, Zenith, West point and Nadir which is usually not shown in the horoscope. Celestial Meridian intersects with horizon at north and south points. Celestial Equator intersects with Horizon at East and South points. Celestial Equator is the extension of the Equator of the Earth onto the Celestial Sphere. Celestial Equator intersects the East and West points of the Horizon. The intersection of Celestial Equator and Celestial Meridian is down from Zenith by an angle equal to the latitude of the place. If the observer is at the on earth’s Equator the Celestial Equator will always be over head on the Zenith. It divides the Celestial Sphere into Northern and Southern hemisphere. All the stars and planets rotate in the path parallel to the Celestial Equator. The celestial Equator intercepts the Horizon at the points directly East and West anywhere on the Earth. Celestial Prime Meridian is the Meridian which joins North Celestial Pole and South Celestial Pole. The circle of Meridian and the circle of Horizon are at the right angle to each other and they form four quadrants. These four quadrants are further divided into 12 cusps and thus we get 12 houses. These two circles form base of the horoscope. The circle of Meridian and circle of Horizon are at the right angle to each other and they form four quadrants. These four quadrants are further divided into three cusps and thus we get twelve houses. The circle of Celestial Meridian and the circle of Horizon form right angle to each. Eclipic The Ecliptic is the apparent path of the Sun on the Celestial sphere as seen from the Earth’s center. The Ecliptic is another great circle in the Celestial Sphere which intersects with the Horizon and Meridian of the observer. The obliquity of the Ecliptic varies in relations to Horizon plane depending on the position of the observer on the Earth. These intersections form base for the formation of the horoscope as they constitute four cardinal points of the house system. The intersection of the Ecliptic and the Horizon constitutes ascendant and descant The intersection of Ecliptic and the Celestial Meridian make up the Medium Coeli and Inum coeli. Ascendant , descendant ,MC and IC are the four points which joins the equal armed cross to their enclosing circle. These four points shows how the energies of the stars, planets and the Sun are integrated into the Earth’s own planetary energy through the cardinal compass point. These four points of the horoscope signifies four cardinal directions which is considered very auspicious and is the four junctions of time. They have natural correspondence with the division of the day marked by dawn, noon sunset and midnight respectively, with the four seasons of the year and also with the four points of the compass. Ascendant is the Eastern point of the Horizon and it the gateway for life energies coming from the Zodiacal belt of the star system. Four cardinal points or angles as they are termed are the most important points in the horoscope. They have a natural correspondence with the division of the day marked by dawn, noon, sunset and midnight respectively, with the four seasons of the year and also with the four points of the compass. respectively, with the four seasons of the year and also with the four points of the compass. Ecliptic intersecting Horizon and Celestial Meridian. Thus all these above mentioned great circles make a framework in the celestial Sphere and intersect with each other. Centre of these all great circles coincide with the centre of the Celestial Sphere. This framework and intersection points are the base for the formation of horoscope. These great circles intersect at the eight points with the Celestial Sphere and these eight points are very crucial points in the diagram of the horoscope. Framework which is base for horoscope formation E = intersection point of Celestial Equator, Horizon and Celestial Sphere at Eastern Horizon W = intersection point of Celestial Equator, Horizon and Celestial Sphere at Western Horizon. S = intersection point of Horizon, Celestial Meridian and Celestial Sphere in the right hand side. N = intersection point of Horizon, Celestial Meridian and Celestial Sphere in the left hand side. O degree Aries= intersection of Celestial equator, Ecliptic and Celestial Sphere at the Eastern Horizon. 0 degree Libra = intersection of Celestial Equator, Ecliptic and Celestial Sphere at the Western Horizon. Asc = intersection point of Ecliptic and Horizon on the Eastern Horizon Des = intersection point of Ecliptic and Horizon on the Western Horizon MC = intersection of Ecliptic and Meridian at the South of Horizon IC = intersection of Ecliptic and Meridian at the North of Horizon. Nadir, Zenith = poles of Celestial Horizon. Prime Vertical= joining East, Zenith, West and Nadir on the Horizon Prime Meridian = Joining 0 degree Aries, North Celestial pole, 0 degree Libra and South Celestial pole. The four cardinal directions East, South, West and South are signified by grand cross + which is considered very auspicious. This + also indicates four junctions of time. They form four Kendras, the four pillars of the energies of the horoscope. These Four cardinal points or angles as they are termed are the most important points in the horoscope. They have a natural correspondence with the division of the day marked by dawn, noon, sunset and midnight respectively, with the four seasons of the year and also with the four points of the compass The four corners which form Kona represent the intersections points of Celestial Equator and Prime Peridian with Celestial Sphere. Together they form fallen cross. The Zodiac In the diagram mentioned below the Zodiac is depicted on its own. The beginning of it is first point Aries which is on the left hand side and the signs follow each other around the circle anti clockwise. The Zodiac rotates around the observer on the Earth making one full circle in 24 hours. Thus the signs follow each other in the zodiac anticlockwise but the Zodiac is moves clockwise making full circle in 24 hours. Planets also move along with the zodiac. At any moment of time each planet is situated somewhere in some degree of Zodiac. The line of the Horizon is very important element of the horoscope. Let us add this line of Horizon in the circle of Zodiac. The point where Zodiac intersects Horizon at Eastern Horizon is ascendant. This is the point where the planets are ascending if we imagine that the Zodiac moving is clockwise while the Horizon stays where it is. Right end side of the Zodiac is West this is where the planets are descending. Descendant is the point where the Ecliptic is crossing the Horizon at the Western Horizon. Sun is shown in the picture above the Horizon quite high in the sky which is the middle of the day. Similarly we can put the remaining nine planets into their appropriate positions in the Zodiac. The visible hemisphere of the Zodiac is divided into six equal parts by semi circles passing through the North and South point of the Horizon the lower hemisphere is similarly divided into six equal parts thus making 12 divisions of the Zodiac. Imagine this portion of the Zodiac is like a rainbow, which is obliquely across the sky from East to West. We can clearly see that this rainbow will cut through the circle indicating the division of houses at certain points. Thus we can clearly mark out signs and degrees of the Zodiac on the cusp of any of six visible houses while the opposite degree of the Zodiac would indicate the degree on the cusps of the opposite invisible houses.