Timeline

Astronomical Timeline
Erling Poulsen

c. 15000 BC

lascauxc. 7000 BC
Drawing in  Chanchal de Mahoma(Spain) representing the phases of the Moon.

c. 5000 BC
The Goseck Henge (Germany) is an early Neolithic Henge-structure with entrances orientated to the rising and setting winter solstice sun.

4800 BC
Calendar stone near the border between Egypt and Sudan.

4500 BC
Stone structures with an astronomical connection in Carnac, France.

4004 BC
On 23 October at 0900, the Universe was created, according to the Anglican Archbishop of Armagh,  James UssherMore.

c. 3000 BC
TheSumerians make lists of bright stars and give the first names to constellations in the zodiac. They also record the movements of the five visible planets. The  Indus culture have also some constellations. More

c. 2600 BC
Religion based on observations of stars reaches its zenith in Egypt during the 3rd dynasty. Later replaced by sun worship.

2485 – 2375 BC

cosmos1c. 2354 BC
The first known female astronomer, En Hedu’anna, lived in Babylon and was the daughter of Sargon.

c. 2300 BC
Chinese sources report observations. The first recorded observation of a comet is from 2296 BC. A solar eclipse is recorded in 2137 BC.

c. 2000 BC
The oldest written sources from  Babylon, including observation of a lunar eclipse.

c. 1900 BC
Stonehenge. The construction period lasted from c. 3100 BC to c. 1500 BC.

c. 1600 BC
Oldest European starmap

gamstjernekort1450 BC
The Egyptians start to use  sundials.

c. 1400 BC
The oldest Egyptian water clocks. The Egyptians introduce a year with 365 days, 12 months of 30 days + 5 extra birthdays for the gods Isis, Osirus, Horus, Nepthys and Set.

1302 BC
Chinese recording of a solar eclipse and recordings of a supernova.

1100 BC
Egyptian  lists of stars along the ecliptic for measurement of time at night. They divided the ecliptic into 10-degree areas, decanes.

800 BC
The Chinese observe sunspots.

c. 650 BC

assurplanc. 600 BC
The birth of Greek science.  Thales assumes that it is possible to understand the Universe using simple rules. The Earth is assumed to float in a large ocean.

c. 580 BC
Anaximander.. The Earth is cylindrical and isolated in space. Nothing supports it. He introduces the idea that stars and planets rest on crystal spheres.

523 BC
Written evidence of the Zodiac from the Babylonians with 12 signs.

c. 500 BC
Pythagorasof Samos proposes, for aesthetic reasons, that the Earth is spherical, the perfect form.

Heraclides. The Earth rotates about its own axis. Mercury and Venus orbit the Sun, which orbits the Earth. The rest of the planets orbit the Earth.

c.430 BC
Philolaus explains the apparent daily rotation of the heavens by saying that the Earth moves around a central fire (that mankind always turns away from). A Counter-Earth moves around the fire, along with all the other heavenly bodies.

c. 400 BC
Plato. Space is infinite and contains a finite universe with the Earth at the centre. All movements must be explained with circular movements. He perceived the visible world as a travesty of the world of ideas.
The Chinese astronomer Kan Te reports sunspots.

365 BC
Chinese observations of Jupiter’s moons.

350 BC
The Chinese astronomer  Shi Shen  makes a catalogue of 800 stars.

c. 340 BC

cosmosc. 320 BC
The Chinese astronomer  Wu Xian publishes a list of 1464 stars in 284 constellations. Shortly after this, the first celestial globe is cast by  Qian Luozh.

c. 300 BC
Aristarchus argues that the Sun is the centre of the solar system. But he gains no supporters.

c. 200 BC
Eratosthenes  of Alexandria measures the size of the Earth by measuring the altitude of the Sun at different locations at the same time. 
Chang Heng begins to map China with a coordinate system. He uses the Mercator projection (“invented” in Europe in 1568) for his star chart.

c. 150 BC
Hipparchus, the greatest observer of antiquity, finds that Aristotle is wrong and introduces movements in epicycles (circles on circles) for the planets. He measures the distance to the Moon.

c. 65 BC
From this time is an astronomical gear machine of bronze, it was found in a Greek shipwreck in 1901.

Antikythera1 AD
Our era begins. However, it was first introduced by Dionysius Exiguus in the 6th century.

c. 100 AD
The Chinese astronomer Zhang Heng constructs an armillary instrument that turns automatically with the heavens. It is driven by a water clock.

c. 150
Ptolemy develops his  system for calculating the location of the planets in the heavens. He publishes a star catalogue with the positions of more than 1000 stars.

c. 420
Martianus Capella publishes a book in which he presents an astronomical system with the Earth at the center of the Universe, the Moon, the Sun, Mars, Jupiter and Saturn in orbit around it and the planets Mercury and Venus in orbit around the Sun.

cosmos2499
The Indian astronomer  Aryabhata  publishes a book in which the rotation of the heavens is explained by saying that the Earth rotates and there is a heliocentric solar system and the planets in elliptic orbits. He determines the length of the year very precisely.

642
The knowledge centre of Alexandria in Egypt is conquered by the Arabs shortly after the collapse of the Roman Empire. Greek astronomy survives in Islam (virtually none of the  major Islamic astronomers are Arabs. Most are Persians). Europe enters the Dark Ages, although recent research has shown that they were not that dark after all.

705-710
Dunhuang starmap, China

721-725
The Chinese measure the size of the Earth.

c. 750
The astronomy the Arabs had taken over in Egypt flourishes in Spain.

813
Al Mamon founds a school of astronomy in Baghdad and translates Ptolemy’s works. Astronomical knowledge from around the world is collected and translated.

903
Al-Sufi draws his star charts.

c. 970
The astronomer  Abu’l Wefa lays the foundations of trigonometry, a major help with astronomical calculations.

1054
Chinese astronomers see and describe a supernova in Taurus. Today it is known as the Crab Nebula.

1259
Nasir al-Din al-Tusi founding an observatory in Maragha, Persia.

cosmos71543
Copernicus revives Aristarchus’ ideas (c. 300 BC).

1572
Tycho Brahe sees a supernova and proves that it is just as far away as the other stars.

1576
Tycho Brahe begins his important observations from the island of  Hven, where he formulates his own astronomical system. The English astronomer  Thomas Digges presents the idea that the stars are at very different and very large distances from the Earth. He has a description of a device that indicates that he constructed a telescope (called PERSPECTIVE GLASS from the Latin perspicere, to see through). It could also have been his father Leonard who made the invention in the 1550s.

1582
Pope Gregory XIII introduces his  calendar, which we still use (it was first introduced in Denmark in 1700).

1596
Fabricius discovers the variable star Mira in the Whale.

brunof081603
Bayer publishes  his star chart. He uses Greek letters to indicate the luminosity of the stars.

1604
Kepler sees a supernova.

1608
The  telescope is invented. It is developed by  Galileo from 1609.

1611
The first observations of sunspots with a telescope. However, they were also described in ancient Chinese sources.

1619
Kepler’s  laws  of planetary motion are published.

1633
Galileo’s ideas are condemned by the Catholic Church. The world’s first State observatory is established in Leiden, Holland.

1642
The world’s second State observatory is established, the Round Tower, Denmark.

rtold1647
Helvelius publishes the first map of the Moon.

1668
Newton builds the first reflecting telescope.

1671
The Paris observatory is established.

1675
The Royal Greenwich Observatory is established in London.

1676
Ole Rømer publishes his discovery that light has a finite speed. He uses the delay in lunar eclipses in connection with Jupiter to measure the speed.

1687
Newton’s “Principia” is published. It contains his theory of gravity.

1705
Halley predicts, based on Newton’s theory, that a comet that was seen in 1682 will pass the Earth again in 1758. It was subsequently named after him.

1725
Flamsteed publishes his star catalogue.

1728
Halley discovers that some stars have moved since antiquity. This is the proper motion of the stars.

1781
Herschel discovers the planet Uranus. Messier’s catalogue of nebulas is published.

1796
Laplace publishes his theory of the origin of the solar system.

1801
Piazzi discovers the first asteroid, Ceres.

1814
Fraunhofer finds dark lines in the Sun’s spectrum.

1838
The first measurement of the distance to a star is made by Bessel.

1845
Lord Rosse discovers the galaxies spiral structure

cosmos41846
Galle discovers the planet Neptune.

1859
Kirchhoff explains the dark lines in the Sun’s spectrum.

1869
The Periodic System of the elements.

1887
The first photographs of the sky.

1889
The first photographs of the Milky Way.

1905
Hertzsprung discovers giant and dwarf stars.

1908
A  massive explosion in Siberia. Probably part of a comet colliding with the Earth.

1911
Hertzsprung and Russell find the connection between stars’ colour and luminosity.

1913
Hertzsprung is the first person to measure the distance to an object outside the Milky Way (The Small Magellanic Cloud) using the variable delta-Cepheid stars.

1915
Einstein’s General Theory of Relativity is published.

1919
Eddington proves” that the Theory of Relativity is correct by measuring the small deflection the Sun’s gravitational field causes to light beams.

cosmos51920
Eddington begins his study of the matter between the stars. The first measurement of the diameter of stars using interferrometry.

1922
Freedman predicts, on the basis of the Theory of Relativity, that the Universe is expanding.

1924
Hubble proves that the galaxies do not belong to the Milky Way.

1925
Eddington publishes his explanation of the inner structure of the stars.

1929
Hubble discovers the ratio between the galaxies’ distance and radial speed.

1930
The planet Pluto is discovered.

1931
Jansky founds radio astronomy.

1946
Radar signals reflected by the Moon are intercepted.

1949
A 5 m telescope in Mt. Palomar is taken into use.

1955
The Jodrell Bank radio telescope is taken into use.

1957
The first satellite in orbit.

1959
The first pictures of the far side of the Moon are taken.

1962
The first X-ray source is discovered in Scorpio.

1963
The first quasar is discovered.
The first planet orbiting another star (Bernard’s star) is discovered.
The quark theory of the structure of matter is published.

1965
Cosmic background radiation is discovered.

1966
The first “soft” landing on the Moon.

1967
The first pulsar is discovered.

1969
The first person on the Moon.

1970
The first “soft” landing on Venus.

1975
A 6 m telescope is taken into use in Russia.

1976
The Viking probes land on Mars.

1977
Rings are discovered around Uranus.

1977
Voyager I and II are launched and pass the planets Jupiter and Saturn in 79-81.

1978
Charon, the moon of Pluto, is discovered.

1986
Voyager II passes Uranus and discovers 6 new moons.
Three satellites pass Halley’s Comet.

1987
Supernova SN1987A flares up, it is the first visible to the naked eye, since 1604th

sn871988
A supernova at a distance of 5 billion light years is discovered.

1989
Voyager II passes Neptune and discovers 8 moons and 3 rings.

1990
The space telescope, Hubble, is launched.

1991
The space probe Galileo passes the asteroid Gaspera.

1992
The COBE satellite discovers irregularities in the background radiation.
The Catholic Church admits that it made a mistake when it condemned Galileo in 1633.

1994
The comet Shoemaker Levy – 9 strikes Jupiter.

1996
Mars Pathfinder begins to transmit data.

1998
The heaviest  quark predicted (“Top”) is found.

1999
A comparison of the luminosity and red shift of remote supernovas indicates that the Universe is expanding faster and faster.

2001
Measurements of  background radiation with a high resolution show that the Universe is probably flat and that the matter we know only constitutes 5 % of its density. 25 % consists of unknown particles (called dark matter) and as much as 70 % consists of something that makes gravitational force repellent at large distances (called dark energy).

2002
It is possible to measure the speed at which gravitational force is propagated. It turns out, as anticipated in Einstein’s theory of 1915, that it happens at the speed of light. Just as when Rømer measured the speed of light in 1676, conditions in connection with the planet Jupiter are used for the measurement. The weak deflection in Jupiter’s gravitational field that occurs with radio radiation from a galaxy depends on, among other things, the speed of gravity. By measuring the deflection, it is possible to measure the speed.

2003
New measurements show that the Universe is 13.7 billion years old.

2005

stjplanetThe first picture of a planet that orbits a star, the star 2M1207 in the Hydra constellation, which is 230 light years away.
A Kuiper belt object that is larger than Pluto is found.

2006
Pluto have not longer status as a planet, now it is a Kuiper belt object.