As any science astrology uses special approaches and instruments to foretell the future. Many well-known people took into consideration the astrologists' advice when making decisions. Horoscope is a diagram showing the positions of stars and planets at the time of an event. Such an event could be a person's birth or other event of importance. Creating horoscopes is a method of looking into the future and foretelling events. The events are related to some points in time and form the grounds of astrological prognosis. The horoscope is interpreted by means of system of signs or by means of calendar significance. Predictions can be based on celestial influences related to the position of the Sun on the day of birth.
Horoscope uses map of the heavens over a particular place at a particular time. In most cases the Earth is in the center. The positions of planets are shown on the map as well as calculated indices such as lunar nodes, midlevel, zodiac signs, stars and others. Astrologers determine the angular relations of planets and other points. The word "horoscope" means "observer of the hour of birth" and is borrowed from Greek.
Astrology as a science uses various concepts. Time and place of event, called "native", is placed on the map and is regarded as the center of "celestial sphere". This sphere is described by a radius. Upon this radius appear objects differently placed from the native. The Earth's equator is projected into space. The Earth and the Sun with their orbits determine the plane of ecliptic Horizon is centered on the native tangentially to the Earth. All these tools help to make the horoscopes precise and reliable.
Astrologists use four important angles in their work. The ascendant is regarded as the most important angle in making personal horoscopes. Particularly important is the placement of ascendant chart ruler. On the opposite side is situated the descendent. When creating a horoscope, the astrologers usually place the ascendant at the left side of the astrological map or chart. During the day the circle of ecliptic passes through the ascendant and advances by one degree. It led to the appearance of the term "rising sign" describing the zodiac sign rising in the point of the ecliptic.
The zodiac is a band on the sphere that contains the sign. In Western astrology people use astrological symbols representing astrological signs. Eastern astrologers use sidereal zodiac, which reflects the position of constellations as they were observed thousands years ago. Astrologists also use the sun sign showing the Sun location in relation to the native. This fact in astrology is known to many people. If the event happens at sunrise the ascendant and the sun sign are the same. Astrologers also speak about houses which are the series of divisions of the ecliptic plane. There are many systems to calculate them. Their position is unchanged in relation to the native.
In order to create a horoscope the astrologer must know the time and place where a person was born. It is considered as the beginning of the event. The local time is then changed into universal time. It is also necessary to change these data into sidereal time at birth. It allows calculating ascendant and midheaven. Then the astrologist looks up a set of tables which show the position of the Sun, Moon and planets for a given year, date and sidereal time taking into consideration the vernal equinox or the fixed stars. The true local time at the place of birth is determined to show visible and hidden from view planets. Houses are calculated as 12 sectors using special tables.