Motion of Grahas

While Galileo mulled about the relative motion and Einstein amused people by stating that ‘when the station approaches the train…’, little they would have imagined that the ancient Rishis had already appreciated up to 8 different types of speeds of the planets due to their motion perceived relative to our position on Earth.


One can simply remember yourself sitting in a moving train and seeing other trains moving in same or opposite directions and you can recall how the speed of the other train varied as it approached your train and overtook or crossed it. Now, imagine the same situation when you would have sat on a carousel horse and the horses in the inner or outer circles appeared to have moved at varying speeds though their speed was actually constant; and moving away or towards us though they are actually moving in one direction. Similar situation happens when planets are observed from the Earth, as studied in Vedic Astrology.

The planets may appear to sometimes move faster, sometimes slower, sometimes appear to be almost stationary or even move in opposite direction. This is because we are observing Moving Planets from a Moving Earth.

As per Parasara (BPHS: Chapter 27: Slokas 21)


वक्रानुवक्रा विकला मन्दा मन्दतरा समा।
चरा चाऽतिचरा चेति ग्रहाणामष्टधा गतिः॥

vakra, anuvakra, vikala, manda, mandatara, sama;
chara and atichara, these are the eight kinds of motions of the grahas.


These eight kinds of motions are understood as follows:


1. vakra (वक्र) = Retrograde Motion

2. anuvakra (अनुवक्र) = Entering the previous rAshi in retrograde motion

3. vikala (विकल) = devoid of motion, or, in other words, Stationary

4. manda (मन्द) = somewhat slower motion than usual

5. mandatara (मन्दतर) = slower than the previous

6. sama (सम) = normal

7. chara (चर) = faster than sama

8. atichara (अतिचर) = entering next Rashi in accelerated motion


Based on these motions, various strengths are assigned to these grahas.

Of the 9 grahas, Sun and Moon, for obvious reason, will never appear to go retrograde; while Rahu and Ketu always appear to go retrograde.