Basics
Grahas (planets)
The words “planet” and “star” are used in a slightly different sense in astrology than in astronomy. For example, Sun (a star) and Moon (a satellite of earth) are called planets in astrology, along with Mars etc. Basically, a graha or a planet is a body that has considerable influence on the living beings on earth. Distant stars have negligible influence on us, but Sun, Moon and planets in the solar system have a great influence on our activities. So the word graha (or planet) is used to describe them.
Seven planets are considered in Indian astrology. They are – Sun, Moon, Mars, Mercury, Jupiter, Venus and Saturn. In addition, two “chaayaa grahas” (shadow planets) are considered in Indian astrology – Rahu and Ketu. These are also called “the north node” and “the south node” respectively (or the head and tail of dragon). Rahu and Ketu are not real planets; they are just some mathematical points.
Apart from these 9 planets, there are 11 moving mathematical points known as Upagrahas (sub-planets or satellites). We also have lagna (ascendant), which is the point that rises on the eastern horizon as the earth rotates around itself. In addition, we have some mathematical points known as “special ascendants".
Rasis (signs)
The positions of all these planets, upagrahas, lagna and special lagnas in the zodiac are measured in degrees, minutes and seconds from the start of the zodiac (which is a fixed point in the sky). These positions are measured as seen from earth and they are called “geocentric positions". For the positions (calculated in degrees, minutes and seconds) of planets, lagna, special lagnas and upagrahas, we also use the words longitude and sphuta. When watched from earth, the longitude of any planet in the skies can be from 00'0'' (0 degrees 0 minutes 0 seconds) to 35959'59''. It should be noted that 00'0'' corresponds to the beginning of the zodiac. Many western astrologers consider Sayana or tropical (moving) zodiac, whereas Nirayana or sidereal (fixed) zodiac is considered in Vedic astrology.
Grahas (planets)
The words “planet” and “star” are used in a slightly different sense in astrology than in astronomy. For example, Sun (a star) and Moon (a satellite of earth) are called planets in astrology, along with Mars etc. Basically, a graha or a planet is a body that has considerable influence on the living beings on earth. Distant stars have negligible influence on us, but Sun, Moon and planets in the solar system have a great influence on our activities. So the word graha (or planet) is used to describe them.
Seven planets are considered in Indian astrology. They are – Sun, Moon, Mars, Mercury, Jupiter, Venus and Saturn. In addition, two “chaayaa grahas” (shadow planets) are considered in Indian astrology – Rahu and Ketu. These are also called “the north node” and “the south node” respectively (or the head and tail of dragon). Rahu and Ketu are not real planets; they are just some mathematical points.
Apart from these 9 planets, there are 11 moving mathematical points known as Upagrahas (sub-planets or satellites). We also have lagna (ascendant), which is the point that rises on the eastern horizon as the earth rotates around itself. In addition, we have some mathematical points known as “special ascendants".
Rasis (signs)
The positions of all these planets, upagrahas, lagna and special lagnas in the zodiac are measured in degrees, minutes and seconds from the start of the zodiac (which is a fixed point in the sky). These positions are measured as seen from earth and they are called “geocentric positions". For the positions (calculated in degrees, minutes and seconds) of planets, lagna, special lagnas and upagrahas, we also use the words longitude and sphuta. When watched from earth, the longitude of any planet in the skies can be from 00'0'' (0 degrees 0 minutes 0 seconds) to 35959'59''. It should be noted that 00'0'' corresponds to the beginning of the zodiac. Many western astrologers consider Sayana or tropical (moving) zodiac, whereas Nirayana or sidereal (fixed) zodiac is considered in Vedic astrology.