Aryabhatt: Earth-Orbit Theory Pioneer

The question asks to identify the Indian astronomer who first presented the Earth-Orbit theory. This theory relates to the movement and position of the Earth in the solar system.

Identifying the Astronomer

Among the notable Indian astronomers listed, Aryabhatt is credited with proposing groundbreaking ideas about the cosmos.

• Aryabhatt, in his work 'Aryabhatiya', suggested that the Earth rotates on its axis, causing the apparent movement of the stars.
• He also proposed a model where the Earth revolves around the Sun (heliocentric concept), though interpretations vary, some suggest a geo-heliocentric model. Regardless, his concept challenged the prevailing geocentric view and was a significant step towards understanding Earth's place in the solar system.
• He presented these ideas centuries before similar concepts gained prominence in the West.

Therefore, Aryabhatt was the first Indian astronomer to present concepts related to the Earth's movement and its orbit, laying the foundation for future astronomical understanding.

Conclusion

Based on historical contributions to astronomical theories regarding the Earth's motion:

The Indian astronomer who presented the Earth-Orbit theory for the very first time was Aryabhatt.