Sirius rises in this year on the first day of the first Egyptian month - a rare event which possibly launches the Egyptian calendar system

Babylonian astronomers name many of the constellations and identify the planets

Phoenician sailors use the pole star for navigational purposes

Thales of Miletus, traditionally the first philosopher, is credited with the prediction of a solar eclipse

The Greeks develop the Babylonian theme of the zodiac, naming it the zodiakos kyklos or circle of animals

The followers of Pythagoras maintain that the earth revolves on its own axis and moves in an orbit

Eudoxus of Cnidus proposes the concept of transparent spheres supporting the bodies visible in the heavens

On the small Greek island of Samos an astronomer, Aristarchus, comes to the startling conclusion that the earth is in orbit round the sun

The Greek astronomer Hipparchus is credited with the invention of the astrolabe, measuring the angle of sun or star above the horizon

The Greek astronomer Hipparchus, mapping the stars, observes but cannot explain the precession of the equinoxes

Hipparchus completes the first scientific star catalogue, mapping some 850 stars

The Maya introduce a calendar which has a cycle of fifty-two years, known as the Calendar Round

Julius Caesar's new calendar is introduced, at a time when its predecessor has become out of step with the seasons by three months

The Jewish calendar, deriving originally from the example of Babylon, is given its lasting form

Astronomers in China and Japan observe the explosion of the supernova which is still visible as the Crab Nebula

Halley's comet, appearing in the Normans' annus mirabilis, is later depicted in the Bayeux tapestry

Polish astronomer Nicolaus Copernicus publishes a book suggesting that the earth moves round the sun

Danish astronomer Tycho Brahe builds Uraniborg, on the island of Hven, and makes it the world's leading observatory

The new and more accurate Gregorian calendar is introduced by Gregory XIII in the papal states

Tycho Brahe enters the service of the emperor Rudolf II in Prague, where he invites Johannes Kepler to join him

Johannes Kepler, in Prague, puts forward the radical proposition that the planets move in elliptical rather than circular orbits

Galileo, with his new powerful telescope, observes the moons of Jupiter and spots moving on the surface of the sun

Galileo publishes his evidence, from sun spots, proving Copernicus right and Ptolemy wrong on the solar system

The Inquisition convicts Galileo of heresy and he denies the truth of Copernicus - on being shown the instruments of torture

Christiaan Huygens, using a home-made telescope, describes accurately the rings of Saturn and discovers the planet's largest moon, Titan