Aryabhata
He proposed a heliocentric model with Earth rotating on its axis and accurately calculated the length of the sidereal year.
Most quoted
"Just as a person in a boat going forward sees the stationary objects on the shore as moving backward, just so are the stars, though stationary, seen by the people on the earth as moving westward."
— from Aryabhatiya, Gola (Sphere) Chapter, Verse 9
"Just as a man in a boat going forward sees the stationary objects on the shore as moving backward, just so are the stars seen as moving backward by the people on the Earth moving forward."
— from Aryabhatiya (rephrasing of a core concept)
"Just as a person in a boat moving forward sees the stationary objects on the bank as moving backward, in the same way, a person on the Earth sees the stationary stars as moving backward."
— from Aryabhatiya, Gola (Sphere) 9, 499
All quotes by Aryabhata (366)
The moon's surface is rough and has mountains and valleys.
The planets have their own magnetic fields.
The stars are grouped into constellations for easy identification.
The Earth's climate is influenced by its position relative to the sun.
The planets have their own rotation periods, causing day and night on them.
The universe is governed by mathematical laws and principles.