Jyotiṣa in the Vedic Era

Under­stand­ing the Ori­gin

The sci­ence of Astron­o­my — Jyotiṣa has fas­ci­nat­ed humans from ear­li­est times and regard­ed by many as the ear­li­est of all sci­ences . It has been put to use in a vari­ety of ways by peo­ple of all walks of life includ­ing farm­ers, trav­ellers, traders, admin­is­tra­tors, cal­en­dar-devel­op­ers, his­to­ri­ans, for­tune-tellers, priests, artists, philoso­phers and many oth­ers. The moti­va­tion ranges from mun­dane pur­pos­es such as keep­ing time, to nav­i­ga­tion, to under­stand­ing issues of human sur­vival, to inter­pret­ing the uni­verse and our place in it.

In India, one can find exam­ples of astro­nom­i­cal ideas all the way from rock art and mega­lith­ic struc­tures, to cod­i­fied mantras in the Vedas describ­ing cer­tain astro­nom­i­cal phe­nom­e­na, to com­pu­ta­tion­al astron­o­my described in the Sid­dhān­tas, to one of the world’s largest pre-tele­scop­ic obser­va­to­ries. This sheer breadth of vari­a­tions one can see, makes it near­ly impos­si­ble to keep track of in its entire­ty. Many of these con­tri­bu­tions were path break­ing and often cru­cial to the devel­op­ment of astron­o­my the world over.

Three Key Eras

In the chronol­o­gy of lit­er­a­ture we find that Jyotiṣa pre­cedes Gaṇitā and the lat­ter’s devel­op­ment was hap­pen­ing in par­al­lel until becom­ing a sep­a­rate field of study itself. And in many cas­es, aspects of Gaṇitā were embed­ded with­in works of Jyotiṣa. Over time, exclu­sive lit­er­a­ture of the var­i­ous sub-top­ics of Gaṇitā were brought forth.

Since their devel­op­ment has been in par­al­lel impact­ing each oth­er mutu­al­ly, we shall also look at them in par­al­lel over the ages. The devel­op­ment of both these fields can broad­ly be put in three eras:

1. Vedic or Pre-Sid­dhan­tic Era (1400–500 BCE) [some stud­ies date fur­ther back to 2500 BCE as the ori­gin]

2. Sid­dhan­tic or Clas­si­cal Era (400‑1200 CE)

3. Post-Sid­dhan­tic or Medieval Era (1200–1850 CE)

In this series too we shall tra­verse through this chronol­o­gy to bring out var­i­ous salient Indi­an advance­ments in these sci­ences.

Jyotiṣa in the Vedic Era

Astron­o­my found in the vedic saṃhitās, brāh­maṇas and allied lit­er­a­ture reveal Indi­a’s roots in the long run­ning pur­suit of excel­lence in Jyotisha & Gaṇitā. For the per­for­mance of the vedic sac­ri­fices at the times pre­scribed by the śās­tras, it was nec­es­sary to have accu­rate knowl­edge of the sci­ence of time.

Astron­o­my in those times was essen­tial­ly the sci­ence of time-deter­mi­na­tion. It cen­tred round the Sun and Moon and its aim was to study the nat­ur­al divi­sions of time caused by the motion of the Sun and Moon, such as days, months, sea­sons, and years, spe­cial atten­tion being paid to the study of the times of occur­rence of new moons, full moons, equinox­es, and sol­stices.

There are many fas­ci­nat­ing aspects of Astron­o­my well-known dur­ing this foun­da­tion­al peri­od of our civ­i­liza­tion. The fol­low­ing is not an exhaus­tive list. But it is intend­ed to bring out many inter­est­ing facts:The Moon is called Sūrya-raś­mi. It means “one which shines by sun­light” (Tait­tirīyasaṃhitā 3.4.7.1). This sheds light on the fact that in the Vedic era we knew that the moon was not a self-illu­mined body.

The depen­dence of Moon’s phas­es on its elon­ga­tion from the Sun is implic­it in a descrip­tion in Śata­patha-brāh­maṇa. 1.5.4.18–20. The Moon’s path was divid­ed into 27 or 28 equal parts, because the Moon took about 27&1/3 days in tra­vers­ing it.

Tait­tirīyabrāh­maṇa (1. 5. 1; 3. 1. 1–2; 3. 1. 4–5) give the names of the 28 nakṣa­tras along with Abhi­jit (Lyra). The Śata­pathabrāh­maṇa (10. 5. 4. 5) gives the names of the 27 nakṣa­tras as well as those of the 27 upa-nakṣa­tras.

Con­stel­la­tions oth­er than nakṣa­tras well known in Ṛgveda(1.24.10; 10.14.11; 10.63.10) are Ṛkṣas(Great & Lit­tle Bear), 2 divine Dogs (Can­is Major & Minor) & the heav­en­ly Boat (Argo Navis). Great Bear is Sap­tarṣi in Śatapatha-brāhmaṇa(2.1.2.4) & Tāṇḍya-brāhmaṇa(1.5.5)

The Aitareya-brāhmaṇa(13. 9) men­tions the con­stel­la­tion of Mṛga or Deer (Ori­on) and the star Mṛgavyād­ha (Sir­ius).

ulkā (mete­ors) and dhū­make­tu (comets) have been men­tioned in the Athar­vave­da (19. 9. 8–9, 19. 9. 10).

Eclipses have been men­tioned and described as caused by Svarb­hānu or Rāhu. The Ṛgve­da (5. 40. 5–9) describes an eclipse of the Sun as brought about by Svarb­hānu.

The names of the lords of the week days stat­ed in Athar­va-jyau­tiṣa are: Āditya (Sun), Soma (Moon), Bhau­ma (the son of Earth), Bṛhas­pati, Bhār­ga­va (the son of Bhṛgu), and Śanaiś­cara (the slow-mov­ing plan­et). Many schol­ars have ascer­tained the ori­gin of nam­ing the days of a week is of Indi­an ori­gin.

The Vedāṅ­ga­jy­otiṣa (~500 BCE), is the ear­li­est Hin­du work deal­ing exclu­sive­ly with astron­o­my. The Vedāṅ­ga­jy­otiṣa has come down to us in two recen­sions, viz. the Ṛgvedic recen­sion (called Ārca-jyotiṣa) and the Yajurvedic recen­sion (called Yājuṣa-jyotiṣa). Their vers­es clear­ly give Indi­a’s cal­en­dri­cal sys­tem and account of months, years, days and day-divi­sions, nakṣa­tras, new moons and full moons, sol­stices, and sea­sons occur­ring in the cycle of five solar years.

In the fol­low­ing edi­tion, we will delve into the devel­op­ment of math­e­mat­ics that had hap­pened in par­al­lel dur­ing the Vedic peri­ods.