- the observatory
- the ancient place for watching the sky and its stars
- the astrolabe
- the sailor's and astronomer's tool for measuring the stars' places
- Ulugh Beg
- the astronomer-king in Samarqand, owner of its famous great observatory
- Maragha
- the city of al-Tusi's great observatory in the land of Persia
- the zij (star tables)
- the tables of the stars and planets and their motions
- al-Battani
- the astronomer who measured the solar year with unmatched precision
- the qibla
- the direction astronomy computes for the worshipper in every land
- Arabic star names
- the sky's Arabic names surviving on the charts of today
- al-Tusi
- the scholar who wrote and taught at Maragha's great observatory
- planetary motion
- the planets' motion, which they explained with their precise models
- calendar reckoning
- the division of the year and time by astronomical reckoning
- navigation
- the art of sailing by the stars across the seas
