For millennia, humanity has looked to the heavens with wonder, charting a course through the vast expanse of Creation. The story of astronomy — a timeline of discovery and innovation — stretches back more than 4,000 years.
The earliest recorded astronomical event dates to around 2000 B.C., when two Chinese astronomers were executed for failing to predict an eclipse — an omen that underscored the importance of celestial knowledge in ancient times. Centuries later, Hipparchus compiled the first known catalog of stars in 129 B.C., followed by Persian astronomer al-Sufi’s catalogue of more than 1,000 stars in 970 A.D.
Between these milestones, Alexandrian scholar Claudius Ptolemy proposed a geocentric, or Earth-centered, model of the universe around 150 A.D., shaping scientific thought for over a millennium. In 1420, Ulugh Beg of Turkestan constructed a massive observatory and produced extensive star tables, paving the way for the Polish astronomer Nicolaus Copernicus, who — on his deathbed in 1543 — published his revolutionary heliocentric theory placing the Sun at the universe’s center.
In 1609, Galileo Galilei’s telescope revealed the craters of the Moon, Jupiter’s moons, and the countless stars of the Milky Way. Decades later, Sir Isaac Newton developed the theory of universal gravitation and introduced the reflecting telescope in 1671.
Predicting the heavens became reality when Edmond Halley forecast the return of a comet in 1758 — confirmed by German farmer and amateur astronomer Johann Palitzsch. The discoveries of Uranus (1781), Neptune (1846), and Pluto (1930) expanded the known Solar System.
In 1932, Karl Jansky detected cosmic radio waves from the Milky Way’s core, now known as Sagittarius A, heralding the age of radio astronomy. These cumulative achievements set the stage for humanity’s greatest leap: the launch of Sputnik 1in 1957, Yuri Gagarin’s spaceflight in 1961, and Neil Armstrong’s historic Moon landing in 1969.