In Sanskrit Retrogression of planets is known as Vakra gati. Vakra means twisted, crooked, winding, roundabout, indirect, evasive and ambiguous.
All the planets go around the sun in their cyclical orbits and
normally appear to move from Aries towards Taurus, at times, appear to move
backwards, from Pisces towards Aquarius and so on. It is an apparent motion
observed only from planet earth when the planet “appears” to move backwards in
the sky.
The Earth moves around the Sun completing
one full revolution in 365.256374 days. [Earth rotates around its axis. For one
such rotation (causing day and night) it takes 23 hours and 56 minutes.This
will cause an observer on Earth to see Sun as rising in the East and setting in
the West.]
Moon completes one revolution around the
Earth in 27.32966 days.
Duration of other planets for one
revolution around the Sun is:
Budha 87.969 days,
Shukra 224.7 days,
Bhouma 686.98 days,
Guru 4332.585 days,
Shani 10759.22 days.
Shani is the slowest of all and has
acquired the name Manda (very slow) or Sthira (permanent).
Rahu and Kethu move backwards at the rate
of one revolution in 6793.394774 days.
