Since ancient times, Hindus have had a tradition of using astronomical references to date events. The approach has the brilliance of not being dependent upon any manmade calender - which any ways has an arbitrary start date and every other event is in relation to that - 2009 AD means 2009 years after birth of Christ, so you need to know when Christ was born to map out an event.
Astronomical references or telling the location of planets and stars (nakshatra) is a simpler and precise way to uniquely date an event without any other reference. It is also fairly unique as the entire combination of planets and stars to occur in the same configuration is very rare or almost impossible.
Bal Gangadhar Tilak (or Lokmanya Tilak as he was popularly called) attempted the same in 1920s. Bhandarkar Institute in Pune have tried to date events in Mahabharata using the same approach.
With advent of powerful softwares that allow rapid multiple calculations - it is now possible to recreate night sky as it looked from a location at a certain point in past / future / current.
So, the author mentioned below used these tools to fit in astronomical events described in the Valmiki Ramayan to reach the date of birth of Lord Ram.
About the Author:
Mr. Pushkar Bhatnagar is an engineer by training and education and an IRS (Indian Revenue Services) officer by profession. He pursues astronomy as a hobby.
He had been hospitalised and was on deathbed after detection of cancer in his kidney. A friend gave him the hindi translation of Valmiki Ramayan (original is in Sanskrit). He always had been a bhakta of Lord Ram.
One thing led to another and culminated in this book.
Sage Valmiki, a contemporary of Lord Ram, mentioned in his magnum opus Ramayana that when Lord Ram was born, the sun was located in Aries,Saturn was in libra, Jupiter and the moon were shining in Cancer, Venus was seen in Pisces while Mars was in Capricorn. Moreover, It was the ninth day of the increasing phase of the moon in the lunar month of Chaitra.
The two illustrations on the cover display, with the help of a powerful software, that these unique astral conditions were present in the sky on January 10,5114 BC.
This path-breaking book employs the scientific advancement of the West to prove the antiquity of the East. Not only the date of birth, the book also discovers the dates of a number of events in the life of Lord Ram by using the Planetarium software.
Table of Contents:
2. The basic concepts of observational astronomy.
3. A brief description of software used for dating.
4. The relevance of Valmiki Ramayana in astronomical dating.
5. The astronomical dating of the Ramayana: the date of birth of Lord Ram.
6. The astronomical dating of the Ramayana: the date of exile of Lord Ram.
7. The calendar during the times of the Ramayana: the calendar of today.
8. The astronomical dating of the Ramayana: the date of battle between Lord Ram and Khar - Dushan.
9. The date of the killing of Bali: a confirmation by a second solar eclipse.
10. The date of Hanuman ji meeting Sita Mata : confirmation by a Lunar eclipse.
11. The astronomical dating of Ramayana: other dates of the fourteenth year of Lord Ram's exile.
12. Archaeological evidence to support the findings.
13. The dating of Ramayana: Mahabharata War and the beginning of Kali Yuga.
14. Astronomical dating: explanation of some related issues.
How to Purchase the Book
In India, you can purchase the book from flipkart.com which I used (Incidentally run by two IIT D alumni who earlier worked with Amazon.com)
The book link for purchasing from flipkart.com is here:
Another source you could purchase from internationally is VedicBooks.net, I have never dealt with them, being based in India, so am clueless about their service.
The book link for purchasing from VedicBooks.net is here:
Read an account written by the author and his mail id by clicking here.