VCA 1: The Astronomical Siddhāntas

Since the cosmology of the astronomical siddhantas is quite similar to traditional Western cosmology, we will begin our discussion of Vedic astronomy by briefly describing the contents of these works and their status in the Vaisnava tradition. In a number of purports in the Caitanya-caritamrta, Srila Prabhupada refers to two of the principal works of this school of astronomy, the Sūrya-siddhanta and the Siddhanta-siromani. The most important of these references is the following:

Here the Sūrya-siddhanta is clearly endorsed as an authentic astronomical treatise, and it is associated with Srila Bhaktisiddhanta Sarasvati Thakura. The Sūrya-siddhanta is an ancient Sanskrit work that, according to the text itself, was spoken by a messenger from the sun-god, Sūrya, to the famous asura Maya Danava at the end of the last Satya-yuga. It was translated into Bengali by Srila Bhaktisiddhanta Sarasvati, who was expert in Vedic astronomy and astrology.

Some insight into Srila Bhaktisiddhanta's connection with Vedic astronomy can be found in the bibliography of his writings. There it is stated,

These statements indicate that Srila Bhaktisiddhanta took considerable interest in Vedic astronomy and astrology during the latter part of the nineteenth century, and they suggest that one of his motives for doing this was to establish that the Vedic astronomical tradition is independent of Greek and European influence. In addition to his Bengali translation of the Sūrya-siddhanta, Srila Bhaktisiddhanta Sarasvati published the following works in his two magazines:

This list includes a translation of the Siddhanta-siromani, by the 11th-century astronomer Bhaskaracarya, and the Arya-siddhanta, by the 6th-century astronomer Aryabhata. Bhattotpala was a well-known astronomical commentator who lived in the 10th century. The other items in this list also deal with astronomy and astrology, but we do not have more information regarding them.

Srila Bhaktisiddhanta Sarasvati also published the Bhaktibhavana Panjika and the Sri Navadvipa Panjika (BS2, pp. 56, 180). A panjika is an almanac that includes dates for religious festivals and special days such as Ekadasi. These dates are traditionally calculated using the rules given in the jyotisa sastras.

During the time of his active preaching as head of the Gauḍiya Math, Srila Bhaktisiddhanta stopped publishing works dealing specifically with astronomy and astrology. However, as we will note later on, Srila Bhaktisiddhanta cites both the Sūrya-siddhanta and the Siddhanta-siromani several times in his Anubhasya commentary on the Caitanya-caritamrta.

It is clear that in recent centuries the Sūrya-siddhanta and similar works have played an important role in Indian culture. They have been regularly used for preparing calendars and for performing astrological calculations. In Section 1.c we cite evidence from the Bhagavatam suggesting that complex astrological and calendrical calculations were also regularly performed in Vedic times. We therefore suggest that similar or identical systems of astronomical calculation must have been known in this period.

Here we should discuss a potential misunderstanding. We have stated that Vaisnavas have traditionally made use of the astronomical siddhantas and that both Srila Prabhupada and Srila Bhaktisiddhanta Sarasvati Thakura have referred to them. At the same time, we have pointed out that the authors of the astronomical siddhantas, such as Bhaskaracarya, have been unable to accept some of the cosmological statements in the Puranas. How could Vaisnava acaryas accept works which criticize the Puranas?

We suggest that the astronomical siddhantas have a different status than transcendental literature such as the Srimad-Bhagavatam. They are authentic in the sense that they belong to a genuine Vedic astronomical tradition, but they are nonetheless human works that may contain imperfections. Many of these works, such as the Siddhanta-siromani, were composed in recent centuries and make use of empirical observations. Others, such as the Sūrya-siddhanta, are attributed to demigods but were transmitted to us by persons who are not spiritually perfect. Thus the Sūrya-siddhanta was recorded by Maya Danava. Srila Prabhupada has said that Maya Danava "is always materially happy because he is favored by Lord Siva, but he cannot achieve spiritual happiness at any time" (SB 5.24cs).

The astronomical siddhantas constitute a practical division of Vedic science, and they have been used as such by Vaisnavas throughout history. The thesis of this book is that these works are surviving remnants of an earlier astronomical science that was fully compatible with the cosmology of the Puranas, and that was disseminated in human society by demigods and great sages. With the progress of Kali-yuga, this astronomical knowledge was largely lost. In recent centuries the knowledge that survived was reworked by various Indian astronomers and brought up to date by means of empirical observations.

Although we do not know anything about the methods of calculation used before the Kali-yuga, they must have had at least the same scope and order of sophistication as the methods presented in the Sūrya-siddhanta. Otherwise they could not have produced comparable results. In presently available Vedic literature, such computational methods are presented only in the astronomical siddhantas and other jyotisa sastras. The Itihasas and Puranas (including the Bhagavatam) do not contain rules for astronomical calculations, and the Vedas contain only the Vedahga-jyotisa, which is a jyotisa sastra but is very brief and rudimentary (VJ).

The following is a brief summary of the topics covered by the Sūrya-siddhanta: (1) computation of the mean and true positions of the planets in the sky, (2) determination of latitude and longitude and local celestial coordinates, (3) prediction of full and partial eclipses of the moon and sun, (4) prediction of conjunctions of planets with stars and other planets, (5) calculation of the rising and setting times of planets and stars, (6) calculation of the moon's phases, (7) calculation of the dates of various astrologically significant planetary combinations (such as Vyatipata), (8) a discussion of cosmography, (9) a discussion of astronomical instruments, and (10) a discussion of kinds of time. We will first discuss the computation of mean and true planetary positions, since it introduces the Sūrya-siddhanta's basic model of the planets and their motion in space.