The History of Astronomy

Cravings in Animal Bones

32,000 BCE

Marks carved into animal bones, and occasionally on the walls of caves, as the records of the lunar cycle. These marks are sets of crescents or lines.

Ornamented engraved out of mammoth ivory, a bracelet with a paleo-astronomical calendar engraved.

15,000 BCE

Paleolithic man had a knowledge of astronomy and not only marked the changing phases of the Moon but also kept a count of time.
This ornamentation of parallel strokes separated in the areas of the zigzags, consists in total of 564 lines (20 lunar months) or 280 days.

The Goseck Circle in Germany

4900 BCE

Consists of four concentric circles, a mound and two wooden stakes, is believed to be the world’s earliest Sun observatory enabling ancient people to accurately measure its path during the course of a solar year.

Newgrange

3200 BCE

Stonehenge

3000 BCE

It is believed that Stonehenge was a temple for the worship of the Sun. It has been argued that this alignment cannot have been accidental and that it would have been possible to use Stonehenge as an Astronomical calculator to predict the dates of eclipses and other astronomical events.

Stonehenge

2500 BCE

The prehistoric monument of Stonehenge in Wiltshire, England, was a sacred place of worship and is aligned to mark the summer and winter solstices.

Earliest Known Solar Eclipse

2137 BCE

Chinese record earliest known solar eclipse

Babylon Star Catalogues

1200 BCE

These star catalogues, written in cuneiform script, contained lists of constellations, individual stars, and planets. The constellations were probably collected from various other sources.

Ancient Astronomical Computer

150 BCE

Ancient astronomical computer, the Antikythera mechanism constructed in ancient Greece capable of predicting star and planet positions, as well as lunar and solar eclipses. (reproduced opposite

Zij al-Sindh by al-Khwarizimi

830

The first major Arabic work of astronomy is the Zij al-Sindh by al-Khwarizmi. The work contains tables for the movements of the Sun, the Moon, and the five planets known at the time. This introduced Ptolemaic concepts into Islamic sciences and marks the turning point in Arabic astronomy. Al-Khwarizmi's work marked the beginning of nontraditional methods of study and calculations.

"A compendium of the science of stars" by al-Farghani

850

al-Farghani wrote Kitab fi Jawani ("A compendium of the science of stars"), containing a summary of Ptolemic cosmography, but it also corrected Ptolemy based on findings of earlier Arab astronomers. Al-Farghani gave revised values for the obliquity of the ecliptic, the precessional movement of the apogees of the Sun and the Moon, and the circumference of the Earth.

Construction of the first astrolabe

928

The earliest surviving astrolabe is constructed by Islamic mathematician–astronomer Mohammad al-Fazari. Astrolabes are the most advanced instruments of their time. The precise measurement of the positions of stars and planets allows Islamic astronomers to compile the most detailed almanacs and star atlases yet.

First heliocentric ideas

1031

Abu Said Sinjari, a contemporary of Abu Rayhan Biruni, suggested the possible heliocentric movement of the Earth around the Sun.

Important Works around Ptolemy

1070

Important works: Abu Ubayd al-Juzjani published the Tarik al-Aflak which indicated the "equant" problem of the Ptolemic model and proposed a solution for the problem. Al-Istidrak ala Batlamyus ("Recapitulation regarding Ptolemy"), included a list of objections to the Ptolemic astronomy. Al-Shuku ala Batlamyus ("Doubts on Ptolemy"). Sums up the inconsistencies of the Ptolemic models. Many astronomers took up the challenge posed in this work and developed alternate models that evaded such errors.

Translation of Islamic and Indian astronomical works

1126

Islamic and Indian astronomical works (including Aryabhatiya and Brahma-Sphuta-Siddhanta) are translated into Latin in Córdoba, Spain in 1126, introducing European astronomers to Islamic and Indian astronomy.

Alfonso X of Castile's Alfonsine tables

1252

The Alfonsine tables provided data for computing the position of the Sun, Moon, and planets relative to the fixed stars.
They contain astronomical data starting on January 1, 1252, the date of the coronation of the King.
They enabled calculation of eclipses and the positions of the planets for any given time based on the Ptolemaic theory, which assumed that the Earth was at the centre of the universe. These were later important for Copernicus.

Nicholas de Cusa suggests his findings in scientific writings

1464

Cardinal Nicholas of Cusa suggested in some of his scientific writings that the Earth revolved around the Sun and that each star is itself a distant sun, therefore that the universe could not be considered finite.

Johannes Müller Regiomontano

1472

Johannes Müller Regiomontano founded the world's first scientific printing press, and in 1472 he published the first printed astronomical textbook, the Theoricae novae Planetarum of his teacher Georg von Peurbach.
Regiomontanus and Bernhard Walther observed the comet of 1472. Regiomontanus tried to estimate its distance from Earth, using the angle of parallax according to David A. Seargeant.

Copernican Revolution

1543

Heliocentric Model

Heliocentric Model by Nicolaus Copernicus

1543

Nicolaus Copernicus publishes "De revolutionibus orbium coelestium" containing his theory that Earth travels around the Sun.

Tycho Brahe establishes geoheliocentrism

1572

A brilliant supernova (SN 1572 - thought, at the time, to be a comet) is observed by Tycho Brahe, who proves that it is traveling beyond Earth's atmosphere and therefore provides the first evidence that the heavens can change.
Although Tycho appreciated the advantages of Copernicus's system, he could not accept the movement of the Earth and settled on geoheliocentrism, meaning the Sun moved around the Earth while the planets orbited the Sun.

Johannes Kepler's Three Laws of Planetary Motion

1609

Johannes Kepler publishes "New Astronomy". He announces his "three laws of planetary motion", replacing the circular orbits of Plato with elliptical ones.
1. The Law of Ellipses
2. The Law of Equal Areas in Equal Time
3. The Law of Harmony

Galileo Galilei's telescope

1610

Galileo Galilei publishes Sidereus Nuncius describing the findings of his observations with the telescope he built. These include spots on the Sun, craters on the Moon, and four satellites of Jupiter. Proving that not everything orbits Earth, he promotes the Copernican view of a Sun-centered universe.

Isaac Newton's reflecting telescope, his Newtonian telescope

1668

The Newtonian telescope is a reflecting telescope invented by Sir Isaac Newton using a concave primary mirror and a flat diagonal secondary mirror. Newton's first reflecting telescope is the earliest known functional reflecting telescope. The Newtonian telescope's simple design makes it very popular with amateur telescope makers.

William Herschel discovers the planet Uranus

1781

Amateur astronomer William Herschel discovers the planet Uranus, although he at first mistakes it for a comet. Uranus is the first planet to be discovered beyond Saturn, which was thought to be the most distant planet in ancient times.

1st photo of Vega's spectrum

1872

Henry Draper takes the first photograph of the spectrum of a star (Vega), showing absorption lines that reveal its chemical makeup. Astronomers begin to see that spectroscopy is the key to understanding how stars evolve. William Huggins uses absorption lines to measure the redshifts of stars, which give the first indication of how fast stars are moving.

Sputnik 1 & Explorer 1

1957

Russia launches the first artificial satellite, Sputnik 1, into orbit, beginning the space age. The US launches its first satellite, Explorer 1, four months later.

First Man on the Moon

1969

Neil Armstrong and Buzz Aldrin step onto the lunar surface on July 20. Apollo 11 is followed by five further landing missions, three carrying a sophisticated Lunar Roving Vehicle.

1st Proof of Existence of Black Holes

2012

First visual proof of existence of black holes is published. Suvi Gezari's team in Johns Hopkins University, using the Hawaiian telescope Pan-STARRS 1, record images of a supermassive black hole 2.7 million light-years away that is swallowing a red giant.

1st Spacecraft on a Soft Landing on the Lunar Far Side & Black Holes

2019

China's Chang'e 4 became the first spacecraft to perform a soft landing on the lunar far side.
In April 2019, the Event Horizon Telescope Collaboration obtained the first image of a black hole which was at the center of galaxy M87, providing more evidence for the existence of supermassive black holes in accordance with general relativity.