Eternal India Encyclopedia

Ancient Concepts, Sciences & Systems

Eternal India

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ASTRONOMY

Curiosity about the celestial objects arose in the human mind

from the very dawn of consciousness. Systematic efforts to under-

stand the celestial phenomena were made in all the advanced

civilisations in the past. Obvious manifestations of these are in the

form of day-night cycles, seasonal north-south movements of the

sun, and systematic motions of the moon and planets among the

stars. Only in recent centuries studies included distant stars,

stellar systems and galaxies. Cosmology or the studies of the

universe was in the human mind from the very early days but the

form and content of the subject have undergone a sea-change in

recent times.

In India the earliest records of such thinkings can be found

among the

Vedas

(Vedanga Jyotisha,

earlier than 1st millenium

B.C.) as well as in following eras

(Jaina Jyotisha,

1st millenium

B.C. and

Siddhanta Jyotisha

1st Millenium A.D.) until the days

when a feedback of Arabian studies influenced Indian astronomical

efforts - Zij Astronomy, 2nd millenium A.D. Development in this

field during the Siddhanta period had greatly influenced Arab ef-

forts during the middle ages. Modern Astronomy may be stated to

begin with Copernicus (1473-1542), followed by Tycho Brahe

(1546-1601), Kepler (1571-1630), Galileo (1564-1642), and

Newton (1642-1727). The subject in its new form was introduced

by the Europeans from the seventeenth century onwards in India.

The ancient Indian astronomers were primarily interested in the

study of the motions of the sun and moon in order to develop a

working calendar to determine the time for the performance of sac-

rifices, religious observances, festivities, marriages and agricul-

tural operations.

Improved astronomical knowledge following the invasion of

India by Alexander in 326 B.C and subsequent contacts with for-

eign savants gave place to a new system of astronomy called the

Surya Siddhanta

which superseded the

Vedanga Jyotisha

by A.D.

400.

The Vedic people took the Sun as the sole light giver of the

universe, the cause of the seasons, winds, controller and the lord of

the world. The Moon was described as

suryarashmi,

one which

shines by the Sun's light. Different phases of the Moon viz

raka

(full-moon day),

anumati

(day preceding full-moon),

kuhu

(new

moon day),

sinivali

(day preceding new moon) etc. were known.

The

Taittiriya Brahmana

gives a full list of names of 15 days of the

light half

(purva paksha

) and also of dark half (

aparapaksha

). The

day was called

vasava

aha

and reckoned from sun-rise to sun-

rise. The day was further divided into different parts. The period

from one moon-rise to the next or from one moon-set to the next

was known as

tithi

(lunar day), which is somewhat different from

the present concept of a tithi of fixed time. That the phenomenon of

new and full-moon is related to Moon's elongation from the Sun

was also correctly guessed. The invisibility of the Moon on the

new-moon day is explained by its being swallowed by the Sun and

its appearance by its being released by the Sun.

The importance attached to the study of astronomy is borne out

by the number of surviving manuscripts on various aspects of

Jyotishastra.

David Pingree who has conducted an extensive sur-

vey of the literature of Indian astronomy states : "At present there

exist in India and outside of it some 100,000 manuscripts of the

various aspects of

Jyotishastra.

The great majority of these were

copied within the 17th, 18th and 19th centuries; for manuscripts

cannot long survive in India except under exceptional circum-

stances. We have, therefore, essentially those texts selected for

study or composed by the scholars of the Mughal and British

rajyas."

The sun was regarded in Vedic literature as the most important

heavenly object and its path, the ecliptic, was considered sacred.

The moon was the next most important and became the obvious

choice for time calculation. It was referred to as "maker of the

month" - the interval between two consecutive new moons or full

moons. There were two systems of reckoning the month based on

the new moon (

amanta

) and the full moon (

pumimanta

The moon's path was observed in relation to the 27

Nakshatras

(Lunar mansions) or asterisms and the lunar zodiac was well

determined. The moon spends a day in each

nakshatra

and momen-

tarily comes into a state of conjunction with the most conspicuous

star in the group of stars. The names of the lunar months were

given on the basis of the

Nakshatra

on which the full moon

occurred. The 12 lunar months were divided into six seasons of two

months each. There were also special names for the solar months.

The 12 lunar months and the corresponding solar months were:

Caitra

(Mar. - Apr.)

Madhu

Vaishakha

(Apr. - May)

Madhava

Jyaishtha

(May - June)

Shukra

Ashadha

(June - July)

Shuci

Shravana

(July - Aug.)

Nabha

Bhadrapada Prausthapada

(Aug. - Sept.) -

Nabhasya

Ashvina or Ashvayuja

(Sept. - Oct.)

Isa

Kartika

(Oct. - Nov.)

Urja

Margashirsa or Agrahayana

(Nov. - Dec.) -

Saha

Pausha or Taisha

(Dec. - Jan.)

Sahasya

Magha

(Jan.- Feb.)

Tapa

Phalguna

(Feb. - Mar.)

Tapasya

The six seasons of the year were:

Vasanta

(Spring, Mar. - May)

Grishma

(Summer, May - July)

Varsha

(the rains, July - Sept.)

Sharad

(Autumn, Sept. - Nov.)

Hemanta

(Winter, Nov. - Jan.)

Shishira

(the cool season, Jan. - Mar.)

In recording dates the basic unit was the

tithi

or lunar day, ap-

proximately 30 of which formed a lunar month of 29

1/2

solar days.

The month was divided into two halves

(paksha)

of 15

tithis

each

beginning with the full

(purnamavasya)

or new (

amavasya

) moons

respectively. In northern India and most of the Deccan the month

began and ended with the full moon, while in the Tamil and south-

ern parts the new moon marked the beginning of the month.

Twelve lunar months total about 354 days. Sixty-two lunar

months are approximately equal to sixty solar months. So every

thirty months an extra month was added to the year. This leap