1.Mechanics of Retrogression:-
Planets move along the zodiac from West to East, around the Sun and when seen from Earth, their motion sometimes seems or appears to be occurring in a reverse direction. This is called as retrogression of planets. This phenomenon of retrogression has special significance in the predictive Astrology in various manners.
The retrogression period of a planet is the period of time during which a planet in our solar system appears to be moving back wards, as we see it against the fixed back drop of the stars. This phenomenon is entirely due to our Earth based perspective only.
In our solar system, the planets are classified as Inferior & Superior planets. Inferior planets are those planets whose Orbit is between Sun & Earth. These planets can not go far away from the Sun. Mercury & Venus fall in this category and these are also called as inner planets. Superior planets are those planets whose Orbits lie outside the Orbit of Earth, and are also known as outer planets. Mars, Jupiter, and Saturn fall in this category of planets.
The superior planets only appear to turn retrograde, when they are about to oppose the Sun. Earth is then posited between the Sun and the planet.
The inferior planets only appear to turn retrograde when they are about to conjoin the Sun. The planet is posited between the Earth & the Sun at that time.
The point in common between all these planets is that they are closest to Earth, when retrograde.
As far as inferior planets are concerned, Mercury goes away from Sun by a maximum of 27 degrees and Venus goes away from Sun by a maximum of 47 degrees. Due to shorter sidereal period available to these planets, these planets race past the Sun & after going ahead they become retrograde. Mercury becomes retrograde when it is between 15 degrees to 27 degrees ahead of Sun. Venus becomes retrogrades, when it is between 27 degrees to 47 degrees ahead of Sun and becomes direct when it is approximately equivalent in degrees behind the Sun. Thus generally, Mercury becomes retrograde, when it is in 2nd house from Sun & becomes direct when it is in 12th house from Sun. Similarly Venus in 2nd/3rd house from Sun becomes retrograde & in 11th/12th house from Sun becomes direct. Superior planets, Mars, Jupiter & Saturn the outer planets, become retrograde when they are generally 120 degrees to 240 degrees away from Sun, or when they are almost in 5,6,7 or 8th houses, away from Sun.
2. Behavior of retrograde planets:-
i) (General Observations)
Erin Sullivan in his Book “Retrograde planets” writes that “If we substitute for ‘introvert’ the ‘retrograde planet’ and for ‘extrovert’ the ‘direct planet’, we come closer to an understanding as to how a retrograde planet operates as an individual within its society. Thinking in terms of planets as individuals in a family or social system, a retrograde planet operates as an introvert. Where as a direct planet, interacts with the other planets, demanding recognition, expecting and delivering challenges, relating & accommodating, adjusting & compromising, and the retrograde planet operates in a sphere of its own, either so alienated from (in the case of the superior planets), or so fused, with (in the case of inferior planets) the solar agent, that it has no perspective beyond its own integrity. It requires greater conscious efforts to prevent the dilution of its energies, with the undifferentiated cosmic, rather than personal meaning. A retrograde planet develops according to some mysterious inner Principles, completely disregarding the social rules, established by the other members of the Solar system”. The learned author further mentions that “the interior world of retrograde planets is neither good nor bad, healthy nor unhealthy, sane nor neurotic. It is a way of seeing life in an intensely personal and self creative way”. “Its ego finds a way to support the planet, rather than the other way round, protecting it from invasion or attack and because of this, a great deal of the un-conscious energy, is invested in defence, rather than development”.
Thus a retrograde planet’s contribution to the whole personality might not be as assertive, as the direct planet, but, this does not mean that it is not as authoritative or influential, as it should have been. It creates and resists as well, because it has an obsession and ego as well, and thus becomes strong as well, on several occasions depending upon other astrological circumstances of its placements etc.
ii) Classics in this context mention as under:-
i) Mantreshwar observes that a retrograde planet not only posses strength, but produces effects similar to those of the exaltation even though such a planet be debilitated.
ii) Kalyan Verma holds in Saravali that retrograde benefics confer kingdom (political power in present day circumstances), while retrograde malefics cause sorrow & aimless wanderings. Jatak Tatwa endorses this view.
iii) Bhavartha Ratnakara says that malefics cause good by having retrograde motion.
iv) Jatak Tatwa endroses it.
v) Phala Deepika mentions that a retrograde planet whose rays are full and brilliant and is debilitated in rashi or in Navamsha, enjoys full strength.
vi) Uttra Kala Mrita-Kalidasa mentions that the retrograde debilitated planets get strength equal to that of an exaltation position. A planet which is associated with a retrograde one, has the strength of half a Rupa in shad bala.
vii) In the calculation of longevity by various astrological mathematical methods like Pinda Ayu method there is no reduction in the contribution of age by the planets which are retrograde for “shatra-kshetra harna”. Similarly under the Amshaya method for the Bharnas (the addition), the retrograde planets treble the contributed age.
viii). Plaladeepika says, that a retrograde planet, whose rays are full and brilliant and is debilitated in rashi or in Navamsha, enjoys full strength.
ix). Jataka Tatwa says, that if a malefic becomes retrograde, it gives benefic results.
x) Saravali of Kalyan Varma says, that a benefic planet in retrogression becomes strong and is capable of conferring kingdom. If a malefic is retrograde, it would cause grief and purposeless wandering.
xi) Uttara Kalamrita-Kalidasha says, a planet exalted in the Rashi and also retrograde, is similar to a debilitated one, and is considered weak, and a retrograde planet in his debilitation, has the strength of exaltation.
xii) Sanket Nidhi by Ramdayalu says, that a Vargottama lagna lord if retrograde, and posited with Atmakaraka, will be strong and beneficial.
The following will be the results of retrograde planets during their dasha period.
(Sarvartha Chintamani Chapter 13 and 14)
Mars : There will be great fear from thief, fire, serpents. The person may reside in forests and also face repulsion (fall from position).
Mercury : The person gets wife, children and wealth. He listens to Puranas and bathe in the sea. He engages himself in charities and ritual sacrifices.
Jupiter : The native becomes financially comfortable, gets wife and son or gains from them, victory in war, close friendship with king and possesses decent goods and clothes and is saintly. He enjoys interesting talks.
Venus : The native gets respect and gains from rulers. He gets royal power and a good post in cabinet of the king, while moving accompanied by drums. He moves with conveyances and paraphernalia of rank and position. He wears colourful clothes. He own ornaments, political powers and influences.
Saturn : The person gets disappointments and failures in work. He suffers loss of power. He gets sorrow from brothers and money.
It can thus be inferred that a retrograde planet is not always weak or more repressed. What a retrograde planet needs is a good obsession. It is further observed that anger is another feature of retrogression. Erin Sullivan mentions in his Book that, “There is a natural rage inherent in the retrograde planet, which needs to become outrage”. This concept of outrage makes the retrograde planet to work better at times for its own efficacy and defense.
3. General Astrological conclusions:-
The general astrological conclusions about retrograde planets as have been experienced are as under:-
- When a planet is retrograde it possesses strength provided it is not malefic.
2. Benefics in retrogression bestow good honour like kingdom (the present-day political power) but the malefic planets as retrogrades, bring sorrow & pain.
3. Retrograde motion gives the planet chesta bala bestowing good or evil according to its functional qualities.
4. Retrograde planet if debilitated or in inimical sign in D-1, or in D-9, charts, will produce good results in its Dasha & antar dasha.
.5. A retrograde planet in natal chart aspected by a retrograde planet in transit will give good results during that period of transit.
6. A retrograde planet in 6, 8 & 12 houses shall produce bad results.
7. A planet retrograde in its own sign shall produce good results.
8. Retrograde planets if exalted will produce the results of debilitated planets & reverse shall be the case with debilitated planets if retrograde.

Shri Deepak Kapoor writes about retrogression in his Book Astronomy and the Mathematical Astrology at page No. 51 as follows:-
The Phenomenon of retrogression can be understood from the above diagram which illustrates an example of Mars as seen from Earth. We know that period of one true revolution of Mars around the Sun, called the sidereal period is of 686.98 days as compared to 365.25 days for the Earth. Due to the faster revolution of the Earth, Mars in its motion as seen against the backdrop of the celestial sphere appears to move backwards which is called a retrograde motion. From the points Marked C to E in the Diagram, Mars appears to be in retrograde motion. This is simultaneously true about other Superior planets as well.