In the most ancient scriptures on vedic astrology
we do not find the names of Rahu and its counterpart, Ketu.
Instead, only seven planets are mentioned.
name of Rahu first appears in the Mahabharata, when we read
the story of the churning of the Ocean of Milk in the search
for ambrosia - the elixir of immortality known as amrita in
Sanskrit. Rahu was the son of Danava Vipracitti by his wife
Simhika, and a brother of Maya Danava, the great magician
Rahu and Ketu are two parts of the same danava
and are 180° apart from each other. Whenever either Sun
or Moon are conjunct with Rahu or Ketu, a solar or lunar eclipse
In astronomy Rahu is considered the dragon's
head and is also known as the north node of Moon, the point
where the Moon's orbit crosses the ecliptic. Ketu is known
as the dragon's tail, which gives birth to comets and meteors
and is known as the descending or the south node of the Moon.
When Sun, Moon, and Rahu or Ketu fall in the
same zodiacal longitude, a solar eclipse takes place. Rahu
is responsible for solar, Ketu for lunar eclipse. This makes
them significant for astronomers and astrologers both.
Though they are included in planets, Rahu and
Ketu are not real luminaries and are regarded as shadow planets.
They do not have ability to cast aspects, as other planets
do, they do not rule any zodiacal signs and are not characterized
as male or female.
Because they are related to Moon as its north
and south nodes, they reflect the basic bipolarity of energy
within the cosmos and the individual. They are both regarded
as malefic half-planets and they bisect the natal chart of
the horoscopes of all individuals. The gemstone related to
Rahu is hessonite.
Rahu rules number 4 in indian