Timeline of solar system astronomy
Antiquity
- 2137 BC, October 22 - Chinese astronomers record a solar eclipse
- ca. 2000 BC - Chinese determine that Jupiter needs 12 years to complete one revolution of its orbit.
- 2nd millennium BC - earliest possible date for the composition of the Babylonian Venus tablet of Ammisaduqa, a 7th century BC copy of a list of observations of the motions of the planet Venus, and the oldest planetary table currently known.
- 1000s BC - The idea of a heliocentric solar system, with the Sun at the center, is possibly first suggested in the Vedic literature of ancient India, which often refer to the Sun as the "centre of spheres".
- ca. 1400 BC - Chinese record the regularity of solar and lunar eclipses and the earliest known Solar prominence
- ca. 1100 BC - Chinese first determine the spring equinox.
- 776 BC - Chinese make the earliest reliable record of solar eclipse.
- 600s BC - Egyptian astronomers alleged to have predicted a solar eclipse
- 613 BC, July - A Comet, possibly Comet Halley, is recorded in Spring and Autumn Annals by the Chinese
- 586 BC - Thales of Miletus alleged to have predicted a solar eclipse
- 350 BC - Aristotle argues for a spherical Earth using lunar eclipses and other observations
- 280 BC - Aristarchus of Samos uses the size of the Earth's shadow on the Moon to estimate that the Moon's radius is one-third that of the Earth, and to estimate sizes and distances for the Moon and Sun
- 200 BC - Eratosthenes uses shadows to determine that the radius of the Earth is roughly 6,400 km
- 150 BC - Hipparchus uses parallax to determine that the distance to the Moon is roughly 380,000 km
- 134 BC - Hipparchus discovers the precession of the equinoxes
- 28 BC - Chinese history book Book of Han makes earliest known dated record of sunspot.
- c. 150 CE - Claudius Ptolemy completes his Almagest that codifies the astronomical knowledge of his time and cements the geocentric model in the West
Middle Ages
- 499 CE - The Indian astronomer-mathematician, Aryabhata, in his Aryabhatiya, propounds a possibly heliocentric solar system of gravitation, and an eccentric epicyclic model of the planets, where the planets follow elliptical orbits around the Sun, and the Moon and planets shine by reflected sunlight
- 500 - Aryabhata accurately computes the Earth's circumference, the solar and lunar eclipses, and the length of Earth's revolution around the Sun
- 620s - Indian mathematician-astronomer Brahmagupta recognizes gravity as a force of attraction, and briefly describes a law of gravitation
- 628 - Brahmagupta gives methods for calculations of the motions and places of various planets, their rising and setting, conjunctions, and calculations of the solar and lunar eclipses
- 687 - Chinese make earliest known record of meteor shower
- 800s - The eldest Banū Mūsā brother, Ja'far Muhammad ibn Mūsā ibn Shākir, hypothesizes that the heavenly bodies and celestial spheres are subject to the same laws of physics as Earth, and proposes that there is a force of attraction between heavenly bodies
- 820 - Muhammad ibn Musa al-Khwarizmi composes his astronomical tables, utilising Hindu-Arabic numerals in his calculations
- 850 - Ahmad ibn Muhammad ibn Kathīr al-Farghānī (Alfraganus) gives values for the obliquity of the ecliptic, the precessional movement of the apogees of the Sun
- 900s - Muhammad ibn Jābir al-Harrānī al-Battānī (Albatenius) discovers that the direction of the Sun's eccentricity is changing, which in modern astronomy is equivalent to the Earth moving in an elliptic orbit around the Sun
- 900s - Ibn Yunus observes more than 10,000 entries for the Sun's position for many years using a large astrolabe with a diameter of nearly 1.4 metres
- 1019 - Abū Rayhān al-Bīrūnī observes and describes the solar eclipse on April 8 and the lunar eclipse on September 17 in detail, and gives the exact latitudes of the stars during the lunar eclipse
- 1021 - Ibn al-Haytham (Alhacen), in his Book of Optics, discovers that the celestial spheres do not consist of solid matter, and he also discovers that the heavens are less dense than the air
- 1031 - Abū al-Rayhān al-Bīrūnī calculates the distance between the Earth and the Sun in his Canon Mas’udicus
- 1150 - Indian mathematician-astronomer Bhaskara, in the Siddhanta Shiromani, calculates the longitudes and latitudes of the planets, lunar and solar eclipses, risings and settings, the Moon's lunar crescent, syzygies, and conjunctions of the planets with each other and with the fixed stars, and explains the three problems of diurnal rotation
- 1150s - Bhaskara calculates the planetary mean motion, ellipses, first visibilities of the planets, the lunar crescent, the seasons, and the length of the Earth's revolution around the Sun to 9 decimal places.
- 1150s - Gerard of Cremona translates Ptolemy's Almagest from Arabic into Latin, eventually leading to its adoption by the Catholic Church as an approved text.
- ~1350 - Ibn al-Shatir anticipates Copernicus by abandoning the equant of Ptolemy in his calculations of planetary motion, and he provides the first empirical model of lunar motion which accurately match observations
Renaissance
- a. 1514 - Nicolaus Copernicus states his heliocentric theory in Commentariolus
- 1543 - Nicolaus Copernicus publishes his heliocentric theory in De revolutionibus orbium coelestium
- 1577 - Tycho Brahe uses parallax to prove that comets are distant entities and not atmospheric phenomena
- 1609 - Johannes Kepler states his first two empirical laws of planetary motion, stating that the orbits of the planets are elliptical rather than circular, and thus resolving many ancient problems with planetary models.
- 1610 - Galileo Galilei discovers Callisto, Europa, Ganymede, and Io, sees Saturn's planetary rings (but does not recognize that they are rings), and observes the phases of Venus, disproving the Ptolemaic system, though not the geocentric model
- 1619 - Johannes Kepler states his third empirical law of planetary motion
- 1655 - Giovanni Domenico Cassini discovers Jupiter's Great Red Spot
- 1656 - Christiaan Huygens identifies Saturn's rings as rings and discovers Titan
- 1665 - Cassini determines the rotational speeds of Jupiter, Mars, and Venus
- 1672 - Cassini discovers Rhea
- 1672 - Jean Richer and Cassini measure the astronomical unit to be about 138,370,000 km
- 1675 - Ole Rømer uses the orbital mechanics of Jupiter's moons to estimate that the speed of light is about 227,000 km/s
Eighteenth century
Nineteenth century
Twentieth century
Twenty-first century
See also
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