Astrology or Jyotish is an integral part of the Vedas. Though in the Vedas the emphasis is more on Astronomy, there was hardly any distinction between Astrology and Astronomy in the Vedic period. Both were studied to determine the auspicious timings for making offerings to propitiate the Gods. The Vedas, therefore, made detailed studies of the stars and the movement of planets across the sky. Eclipses had to be timed because they signified evil portents. The obliteration of the luminaries, however temporary, could not be good for the mere mortals.
The stories regarding the birth of planets are found in the Puranas, which are of a later vintage. There are 18 Puranas. They deal with the story of creation, the tussle between the Gods and demons, the various forms and reincarnations of Lord Vishnu and sometimes even the genealogy of kings on earth. The same story appears in several Puarnas and predictably, the versions differ from one another.
In the early stages, Puranas were also an oral tradition. While elaborate care was taken to preserve the integrity of the Vedas so that distortions might not creep into them through repeated retelling, no such precaution was thought necessary for the Puranas. The Vedas were sacrosanct. The Puranas were not quite as sacred.
Methods of memorizing the Vedas were very interesting. Let us assume that we have a sentence in the Vedas - "God is good". (Actually, Vedas do not dish out such simple sentences. We have cooked up an example to illustrate a point). One student would memorize it as "God is good". That is normal. We all go through a similar exercise the night before our exams.
But a second one would do it in a strange form:
"Doog si dog" - memorizing it backwards. There would be a third who would do something even more strange:
"Go od di is sg go oo od".
This gobbledygook can be easily unscrambled to find the original message. There were many more ways; all were simultaneously practiced to ensure that if corruption took place in one it would be rectified by comparing it with the others.
In one method two sentences would be mixed up in a manner not entirely unlike sending scrambled digital packets across the broad bandwidth.
But enough of that! Let us go back to the story of the planets as given in some of the Puranas. These were subsequently changed, modified, expanded until they became part of a rich folklore of India with all its sectarian bias and regional garnish.
So the stores we bring to you here originated in the Puranas but got extensively revised through successive retelling!