The Rigveda is the oldest of the four Vedas and is believed to have been composed between 1500 and 1200 BCE.

The Rigveda primarily consists of hymns and prayers used in various religious rituals and ceremonies.

The Atharvaveda contains numerous hymns and spells related to various aspects of life, including astronomy and astrology.

Lagadha, an ancient Indian astronomer, is believed to have developed the concept of the zodiac and divided the ecliptic into 12 equal parts.

The Rigveda contains the earliest known reference to the constellation of Orion, known as Mrigashira in Sanskrit.

Yantras were ancient Indian astronomical instruments used to measure the positions of celestial bodies and calculate astronomical data.

The Atharvaveda contains references to the precession of the equinoxes, the gradual shift in the position of the equinoxes over time.

The Surya Siddhanta is an ancient Indian astronomical text that contains detailed observations and calculations related to solar and lunar eclipses.

The Atharvaveda contains references to the Earth's rotation on its axis, known as the daily motion of the Earth.

Aryabhata developed the theory of planetary motion known as the 'mean motion' theory, which provided a more accurate calculation of planetary positions.

The Atharvaveda contains references to the Earth's revolution around the Sun, known as the annual motion of the Earth.

The Surya Siddhanta discusses the concept of the Earth's spherical shape and provides calculations for determining the Earth's circumference.

The Atharvaveda contains references to the Earth's shadow causing lunar eclipses, known as the lunar eclipse.

Bhaskara II developed the theory of planetary motion known as the 'true motion' theory, which provided a more accurate calculation of planetary positions.