What astronomy studies: its history and links with other sciences
Astronomy is the science that studies celestial bodies – planets, stars, galaxies – their motion, structure, origin and development, and the Universe as a whole. Its branches are astrometry (measuring positions and motions), celestial mechanics (calculating motion with the laws of gravity), astrophysics (physical nature), cosmogony (the origin of bodies) and cosmology (the Universe as a whole). In ancient Babylon, Egypt and Greece sky observations served calendars and navigation; Ptolemy (2nd century CE) described a model with the Earth at the centre, while Copernicus published a Sun-centred model in 1543. Galileo began telescopic observations in 1609–1610, and Newton published the law of universal gravitation in 1687. Scholars of Central Asia contributed greatly: al-Khwarizmi (9th century) compiled astronomical tables, al-Farghani (9th century) wrote a well-known book on the motions of the heavens, Biruni (973–1048) measured the Earth’s radius with a method of his own, and Ulugh Beg (1394–1449) had an observatory built in Samarkand in the 1420s, where he and his scholars compiled a star catalogue. Astronomy is closely tied to physics, mathematics, geography and chemistry, and it matters in practice for space technology and communications.
Make a classroom wall timeline “Chronology of astronomy”: each student writes one scientist or discovery (with its year) on paper and hangs it in order. No observing is needed.