The Rigveda, one of the four Vedas, contains hymns that mention celestial bodies and astronomical phenomena, making it the earliest known astronomical text in India.

Vedic astronomy primarily focused on studying constellations and their significance in astrology and religious rituals.

Lagadha, an ancient Indian astronomer, is believed to have developed the concept of the zodiac, dividing the ecliptic into twelve equal parts.

The gnomon, a simple but effective instrument, was used in ancient India to measure the positions of celestial bodies and determine the time of day.

Aryabhata, a renowned ancient Indian astronomer, proposed the heliocentric model of the solar system, where the Earth and other planets revolve around the Sun.

Jantar Mantar, a series of astronomical observatories built by Maharaja Jai Singh II, is a testament to the advanced astronomical knowledge and instrumentation in ancient India.

Aryabhata, in his treatise Aryabhatiya, calculated the value of pi (π) to four decimal places, demonstrating the mathematical prowess of ancient Indian astronomers.

The Atharvaveda, one of the four Vedas, contains detailed descriptions of constellations and their significance in astrology and religious rituals.

Varahamihira, a renowned ancient Indian astronomer, developed a method for calculating the time of eclipses, demonstrating the advanced astronomical knowledge of the period.

The quadrant, an astronomical instrument, was used in ancient India to measure the altitude of celestial bodies above the horizon.

Bhaskara II, a renowned ancient Indian astronomer, proposed the existence of invisible forces holding celestial bodies in place, an early concept of gravitational forces.

The Yajurveda, one of the four Vedas, contains detailed descriptions of planetary motion and their significance in astrology and religious rituals.

Aryabhata, in his treatise Aryabhatiya, developed a method for calculating the distance to the Moon, demonstrating the advanced astronomical knowledge of the period.

The sundial, an ancient astronomical instrument, was used in India to measure the time of day based on the position of the Sun.

Bhaskara II, in his treatise Siddhanta Shiromani, proposed the existence of a ninth planet beyond Saturn, an early concept of the existence of Pluto.