History of Astronomy

The Age of Discovery

European Astronomy related to the
geographic discoveries of the 15th to 17th Century

In the mid-15th century, European sailors started discovering the southern skies. The first Europeans to see the Southern Cross in its full glory were the Portuguese sailors of the fleet of Prince Henry the Navigator, sailing along the coast of West Africa, reaching Cape Verde in 1456 and Cape of Good Hope in 1497. In the early 16th century, they were followed by the sailors of the Portuguese India Armadas, which sailed to India and Brazil.

Then came the Dutch East India Company and then a French astronomer, who set up his observatory at the southern tip of Africa. By the middle of the 18th century, 37 new southern constellations that were not visible to antique and renaissance astronomers were catalogued.

The primary focus of this site is not astronomy, but Star Lore, which is folklore based upon stars and star patterns. We try to create a collection of mythical stories about stars and constellations from all over the world. However, to better understand the myths and legends of stars and constellations, a brief history of the development of our modern constellations might be helpful. This is by no means a scientific paper on the history of astronomy, but merely an illustrated collection of highlights of that history, along with some links to what we think are reliable sources on the subject.

Bits of the history of Astronomy during the Age of Discovery

Henry the Navigator (1394 – 1460)

Although he never set sail for an expedition himself, prince Henry the Navigator was a crucial figure in the Age of Discovery. Under his supervision, Portuguese ships explored the Atlantic Ocean and the West African coast past Cabo Verde, all the way to modern day's Sierra Leone. In 1488, 28 years after Henry's death, Bartolomeu Dias reached the Cape of Good Hope.

Abraham Zacuto, Jewish astronomer at the court of Henry's brother, King John II of Portugal developed the instruments crucial for maritime navigation and provided Henry's sailors with the necessary astronomical charts.

In 1497, Zacuto advised Vasco da Gama before his voyage to India.

Source: Wikipedia, Wikipedia

Mariner's Astrolabe from 1602
Source: American History

The Portuguese India Armadas and the Southern Cross (1497 - 1511)

When watched from Egypt or the Middle East, the Southern Cross is a dim group of stars, barely rising over the horizon. So, it is not surprising, that Ptolemy regarded those stars only as a small asterism, belonging to the constellation Centaurus.

In the mid-15th century, European sailors found that sailing further south, the Cross became quite a bright constellation.

The first Europeans to see the Southern Cross in its full glory were the Portuguese sailors of the fleet of Prince Henry the Navigator, sailing along the coast of West Africa, reaching Cape Verde in 1456 and Cape of Good Hope in 1497. In the early 16th century, they were followed by the sailors of the Portuguese India Armadas, which sailed to India and Brazil.

The first report of the Cross as a bright constellation came from Alvise Cadamosto, who observed it in 1455 at the mouth of the Gambia River.

Between 1497 and 1511, thirteen Armadas sailed from Portugal to India and back. Little is know about astronomical discoveries during these voyages, but the Second Armada in 1500 had an astronomer named João Faras on board.

Along the way to the Cape of Good Hope, the armada sailed far enough to the west to discover the easternmost part of Brazil. There, João created a first sketch of the stars of the Southern Hemisphere, famously identifying the Southern Cross.

In 1589, the Southern Cross was first shown as an independent constellation on a globe manufactured by Dutch cartographers Jacob Floris van Langren and Petrus Plancius.

In 1603, it was entered as a separate constellation in de Houtman's Catalogue and in the Uranometria.

Source: Wikipedia

The Southern Cross
Source: quora.com

Mestre João at the Brazilian coast
Source: Recanto das Letras

Magellan's Clouds (1501)

In 1519, when Ferdinand Magellan's ships crossed the equator, his astronomer, Venician Antonio Pigafetta noticed two diffuse clouds in the southern sky. A long time later, the two irregular dwarf galaxies would be named the Magellanic Clouds.

The Clouds had been know to native people in the southern hemisphere since prehistoric times.

The first European report of the clouds was published by Italian explorer Amerigo Vespucci in 1503. He observed them in 1501 on a voyage along the coast of Brazil.

Vespucci did not provide any coordinates of the Clouds. The first reliable sketch was given by Italian explorer Andrea Corsali, who in 1515 sailed around the Cape of Good Hope on a Portuguese ship.

However, after naming the the Magellanic Clouds, the credit for the discovery was given to Magellan's expedition, putting the first circumnavigation of Earth firmly in the sky.

Sketch from Andrea Corsali's letter
Source: Michel Dennefeld

Sources: Wikipedia, Michel Dennefeld: A history of the Magellanic Clouds and the European exploration of the Southern Hemisphere

The first new constellations since Ptolemy (1536)

In 1536, German cartographer Caspar Vopel published a celestial globe showing two new constellations in addition to Ptolemy's forty-eight.

In Ptolemy's Almagest the asterism Coma Berenices was part of the constellation Leo. The first one to name the asterism was Greek astronomer Conon of Samos (ca.280 – ca. 220 BC).

Vopel's second new constellation was Antinous, an asterism originally belonging to Ptolemy's Aquila. The asterism was first separated by Roman emperor Hadrian, who named it after his favourite beloved Antinous.

Vopel, and after him Gerardus Mercator and Tycho Brahe listed Coma Berenices and Antinous as separate constellations. In 1922, when the International Astronomical Union finalized today's 88 constellations, Coma Berenices was officially designated a constellation, while Antinous was re-merged with Aquila.

Caspar Vopelius
Source: Wikipedia

Sources: Ian Ridpath, Elly Dekker: Caspar Vopel's Ventures in Sixteenth-Century Celestial Cartography

The Prutenic Tables (1551)

In 1551, in a first attempt to replace the geocentric-era based Alfonsine Tables, German mathematician and astronomer Erasmus Reinhold published a set of astronomical tables to promote Copernicus' heliocentric model.

The tables were called the Prutenic Tables (Prutenic being Latin for Prussian) in honor of Reinhold's supporter and financier, Albert I, Duke of Prussia.

The world warmed up only slowly to the new concept. It wasn't until the works of Johannes Kepler in the following century, that heliocentrism was generally accepted.

Source: Wikipedia

Title page with Erasmus Reinhold’s signature
Source: Univ. of Aberdeen

Tycho's Supernova (1572)

In November 1572, astronomers all over the world witnessed the appearance of a "new star" in the constellation Cassiopeia. The most detailed observation was done by Danish astronomer Tycho Brahe, which is why the phenomenon became known as Tycho's Supernova.

In 1573, Tycho published an extensive work on the Supernova, called De nova et nullius aevi memoria prius visa stella, "Concerning the Star, new and never before seen in the life or memory of anyone."

Happening only 29 years after Copernicus' Revolutions of the Heavenly Spheres, the Supernova happened at a time when all of astronomy was changing. The appearance of a "New Star" seriously challenged the Aristotelian dogma of the unchangeability of the realm of stars.

Sources: Wikipedia, atlasobscura.com, Ian Ridpath

Tycho's map of the supernova in the constellation Cassiopeia
Source: Wikipedia

Copernicus in Translation (1576)

In 1553, English mathematician Leonard Digges published a Perpetual calendar called A General Prognostication.

In 1576, his son Thomas Digges published a new edition with an appendix that contained a translation of several chapters from Copernicus' Revolutions of the Heavenly Spheres. This was the first publication of Copernicus' book in English, further promoting the heliocentric model.

Source: Wikipedia

Digges' drawing of the heliocentric model
Source: Wikipedia

Tycho's Astronomy Castle and Star Castle (1576 - 1597)

In 1572, Tycho Brahe published a first version of Astronomiae Instauratae Progymnasmata, introducing the Tychonic model of the Solar System, which was a geo-heliocentric model with the Moon and Sun orbiting Earth at the center of the system, and the other planets orbiting the Sun.

In 1576, Tycho built Uraniborg the the first custom-built observatory in modern Europe on the (then) Danish island Hven. The observatory is named after Urania, the Muse of Astronomy.

Here, Tycho started working on a truly gargantuan project: For the last fourteen centuries, all star catalogues were mere translations of Ptolemy’s Almagest. Tycho set out to create the first new major star catalogue since the second century AD.

In 1586, Tycho added a second observatory, Stjerneborg, Danish for Star Castle.

Unfortunately, in 1597, before he could finish his ambitious project, Tycho had some serious disagreements with the new Danish king Christian IV, lost his funding and went into exile in Bohemia.

Sources:Ian Ridpath, Science Museum Group

Uraniborg, Atlas Maior
Source: Wikipedia

Stjerneborg Observatory
© Science Museum Group

The Great Comet of 1577

In November 1577 a non-periodic comet passed so close to earth that its brightness equaled that of the moon and its tail spun over 60 degrees.

The most detailed observation were done by Danish astronomer Tycho Brahe in Prague and by Taqi ad-Din at the Constantinopel observatory.

Tycho made thousands of very precise measurements of the comet's path, producing for the first time enough evidence that comets are not an atmospheric phenomenon but exist outside the Earth's atmosphere.

Johannes Kepler, who became Tycho's assistant in 1600 saw proof enough to displace the theory of celestial spheres by the comet's behavior. Later, he used Tycho's observations developing his Laws of planetary motion.

Source: Wikipedia

Great Comet over Prague
November 12, 1577
Engraving by Jiri Daschitzky
Source: Wikipedia

The shortest Year in History - thanks to a New Calendar (1582)

After years of preparation and 74 years after it was first suggested by German priest Johannes Stöffler, Pope Gregory XIII corrected the Julian calendar with the improved Gregorian Calendar.

The new calendar shortened the average year by 0.0075 days, stopping the drift of the calendar with respect to the equinoxes. It also introduced the leap year.

To correct the drift of the equinoxes that had occurred over the years, the year 1582 was cut eleven days short and Thursday, October 4, 1582 was followed by Friday, October 15, 1582.

Another change was the definition of the new year. In the Julian calendar, the new year started April 1. That was now changed to January 1 and the Julian New Year's Day became known as "fool's holiday" for those who did not accept the change.

Sources: Wikipedia, Space Today

One of the first printed
editions of the new calendar
Source: Wikipedia

The maps and globes of Petrus Plancius (1589 - 1603)

In 1589, the new ocnstellation were presented visually for the first time on a celestial globe made by Dutch cartographer Floris van Langren. The globe showed the Southern Cross, the Magellanic Clouds (though without a lable) and a Triangulus Antarcticus. That is not the later Triangulum Australe but rather a group of stars observed by Italian navigator Amerigo Vespucci whose records, unfortunately, got lost.

Sources: Wikipedia, Ian Ridpath

Crux and Triangulus Antarcticus on van Langren's celestial globe
Source: Royal Museum Greenwitch
The globe and others like it were initiated by Dutch cartographer Petrus Plancius, who was one of the most notable people in the development of modern constellations. In addition to his enormous influence on other astronomers, Plancius' name is directly related to four constellations. In 1592, he created the constellation Columba (The Dove) from a faint group of stars outside Canis Major and displays it on a large wall map.

In 1603, on his initiative, Crux, the Southern Cross, was listed as a separate constellation in the Uranometria.

Six additional faint constellations in the northern sky developed by Plancius were first shown in 1624 in Usus Astronomicus Planisphaerii Stellati, a book by German astronomer Jakob Bartsch. Only two of them, Monoceros (Unicorn) and Camelopardalis (Giraffe) made it onto the the list approved in 1922 by the International Astronomical Union.

Plancius was one of the founders of the Dutch East India Company. He drew over 100 maps for the Dutch fleets exploring the world. Plancius also trained the pilots of the first Dutch Fleet bound for the East Indies to make astronomical observations during their journey. The result was sixteen new southern constellations.

Sources: Wikipedia, Ian Ridpath

Mapping the stars of Dutch East India (1595 - 1603)

In 1595, the first Dutch fleet (called Eerste Schipvaart or First Expedition) set sail for the East Indies. The navigators on board these ships would soon be writing their names in the southern skies.

Pieter Dirkszoon Keyser made most of his observations while the ships stayed in Madagascar for repairs and resupplies. He continued his observations until the ships arrived in Sumatra,but in 1597, when the 81 surviving members of the expedition returned to Holland, Keyser was one of the 167 that didn't make it home.

Frederick de Houtman, brother of the fleet's commander was one of the navigators assisting Keyser in Madagascar.

The other two navigators were Vechter Willemsz (who died during the voyage from Madagascar to Sumatra) and Pieter Stockmans (who later became a captain in the fleet of John Davis).

The first Dutch expedition brought back star charts containing twelve new constellations and it was - again - Petrus Plancius who first showed the new constellations; on a globe manufactured in 1598. Another globe was made by Dutch cartographer Jodocus Hondius in 1600.

On a second voyage from 1598 to 1602, Frederick de Houtman consolidated the astronomical work of the first Dutch expedition and eventually brought back star charts documenting the observation of 303 fixed stars, 196 of which were new to astronomers on the northern hemisphere. He published his observations as appendix to his Malay and Madagascan dictionary.

Then, in 1603, Uranometria, the first star atlas showing the entire sky was published by German cartographer Johann Bayer.

In hindsight, it was impossible to decipher, which of the new constellations were first observed by Keyser and which by de Houtman. Consequently, they were both jointly credited with the introduction of the following new constellations:

Apus (Bird of Paradise), Chamaeleon (Chameleon), Dorado (Goldfish), Grus (Crane), Hydrus (Lesser Water-Snake), Indus (Indian), Musca (Fly), also known as Apis (Bee), Pavo (Peacock), Phoenix (Phoenix), Triangulum Australe (Southern Triangle), Tucana (Toucan), and Volans (Flying Fish).

Sources: Wikipedia, Wikipedia, Ian Ridpath, David Thompson

Title page of the Dutch sailing handbook "Light of Navigation" (1608) showing navigators using compass, hourglass, astrolabes, globes, divider and Jacob's staff.
Source: Wikipedia

Chart 49 of Johann Bayer’s Uranometria, showing the new constellations of the southern sky.
Source: Ian Ridpath

Houtman's listings of Musca (De Vlieghe)
and Volans (De vlieghende Visch).
Source: Utrecht University Library

Mysterium Cosmographicum (1597)

Mysterium Cosmographicum (The Cosmographic Mystery), published by Johannes Kepler in 1597 was the first published defense of the Copernican system.

Kepler proposed that the distance relationships between the six planets known at that time could be understood in terms of the five Platonic solids, enclosed within a sphere that represented the orbit of Saturn.

In Kepler's cosmological theory, based on the Copernican system, the five Platonic solids dictated the structure of the universe and reflected God's plan through geometry.

This was the second attempt since Copernicus to say that the theory of heliocentrism is physically true.

Source: Wikipedia

Kepler's Platonic solid model of the Solar System
source: Wikipedia

Giordano Bruno - A martyr of science (1600)

In spite of the scientific evidens delivered by Kepler, the Roman Church held on to old ideas and one astronomer had to pay the ultimate price:

Giordano Bruno (1548 - 1600), an Italian Dominican friar, philosopher, mathematician, poet and cosmological theorist developed an important enhancement to Copernicus' heliocentric model.

In Copernicus' model, the universe still had a center - the Sun. Not only all the planets, but also all the fixed stars revolved around that center. Bruno suggested that the universe was infinite and could not have a center and that instead, the stars were distant suns surrounded by their own planets which might even foster life of their own.

This concept, known as Cosmic pluralism, was unacceptable for the Catholic Church. Consequently, starting in 1593, he was tried for heresy by the Roman Inquisition. On February 17, 1600, Giordano Bruno was burned at the stake in Rome's Campo de' Fiori.

Source: Wikipedia

Giordano Bruno Burning
© Andre Durand, 2000

Copernicus and the Forbidden City (1601)

In 1582, Italian Jesuite priest Matteo Ricci arrived in Macau to work at the Jesuit China mission which was founded in 1552.

Ricci was one of the first Europeans to study the Chinese language and customs. Not limiting his mission to Christian missionary work, Ricci introduced Western science, mathematics, astronomy and visual arts to the Chinese imperial court.

He published the first map of the world, showing all the latest discoveries in Chinese language and introduced the Copernican principles to Chinese scholars.

In 1601, Matteo Ricci was the first European to enter the Forbidden City of Beijing on an invitation by emperor Wanli. He became the emperor's court advisor in matters of astronomy and calendrical science.

Source: Wikipedia

Matteo Ricci with Xu Guangqi
Source: Wikimedia

De Mundi Aetherei (1602)

Tycho Brahe (1546 - 1601) is considered the greatest astronomical observer of the pre-telescopic era. For decades, he worked on the first true overhaul of Ptolemy's Almagest in 1,400 years.

Tycho's accuracy far surpassed all previous updates of the ancient Greek tables. His list covered all but four of Ptolemy's constellations (Lupus, Ara, Corona Australis, and Piscis Austrinus could not be observed from Tycho's northern European position). He also included the two above mentioned new constellations Coma Berenices and Antinous. For a number of Ptolemy's constellations, Tycho used alternative names. The complete list with all alternatives can be found in Ian Ridpath's outstanding work.

In 1588, Tycho published a first short version of De Mundi Aetherei, containing his theories stated in Astronomiae Instauratae Progymnasmata and his observation of the Great Comet of 1577, but he didn't live to see the publication of his complete work.

Front page of Tycho Brahe's
Star Catalogue
Source: Library of Congress
A first subset of 777 stars, the De Mundi Aetherei Recentioribus Phaenomenis Liber Secundus (Second Book About Recent Phenomena in the Celestial World) was published in 1602, the year after his death. The complete list of 1007 stars was published by Johannes Kepler and formed the base of Kepler's Rudolphine Tables, published in 1627.

Sources: Wikipedia, Ian Ridpath, F. Verbunt and R.H.van Gent

Uranometria (1603)

In 1603, the first star atlas showing the entire sky was published by German cartographer Johann Bayer.

The Uranometria contained two overview charts for the northern and the southern hemisphere, 48 charts for each of Ptolemy's constellations and one chart for the twelve new constellations reported by Keyser and de Houtman.

The charts for Ptolemy's constellation in the 1603 edition were based on Tycho Brahe's De Mundi Aetherei catalogue. Later editions used the Rudolphine Tables, published in 1627 by Johannes Kepler.

Sources: Wikipedia, Wikipedia, Ian Ridpath, wallhapp.com

Twelve new southern constellations
in a 1661 edition of Uranometria
Source: Atlas Obscura
Uranometria was the first star catalogue to introduce a designation system for stars. The Bayer designation consisted of a Greek letter (in order of apparent magnitude) and the genitive form of its parent constellation's Latin name.

Uranometry is derived from the Greek words for sky and measuring. Thus, Uranometry means "measuring the sky", while Geometry means "measuring the earth."

Kepler's Supernova (1604)

Only 32 years after Tycho's Supernova, another "New Star" appeared - this time in the "foot" of the constellation Ophiuchus.

The event was first observed on October 9, 1604 by Italian astronomer Lodovico delle Colombe. German astronomer Johannes Kepler began his observations on October 17, consequently tracking the object for an entire year, which is why the object was named after him.

In 1606, Kepler wrote a book - De Stella Nova in Pede Serpentarii (On the New Star in the Foot of the Serpent Handler) about the event.

This being the second observation of a supernova within the same generation, the event raised further doubts about the Aristotelian doctrine which stated that the distant stars were fixed in the firmament. However, Kepler was not convinced that the event was related to a star, discribing the light not as a star, but as a "random concatenation of atoms in the heavens."

Sources: Wikipedia, atlasobscura.com

Kepler's sketch of the location of the supernova
(highlighted by the author.)
Source: Wikipedia

Astronomia Nova (1609)

For ten years, Johannes Kepler had observed the orbit of Mars, coming to the conclusion that it was not circular, but elliptical. This observation was the base of the first of his three Laws on Planetary Motion, which states that: The orbit of a planet is an ellipse with the Sun at one of the two foci.

Kepler published his findings in 1609 in Astronomia nova. The book provided strong arguments for the Copernican heliocentric model and contributed valuable insight into the movement of the planets.

According to Wikipedia, it is "one of the most important works of the scientific revolution.

More about Kepler's other important publications can be found in the next section.

Source: Wikipedia

Astronomia Nova
Source: Christie's Auctions

A new way of looking at the stars (1610)

In 1608, Dutch spectacle-maker Hans Lipperhey invented the refracting telescope (or, at least, he is credited with the invention).

Only two years later, the first astronomers pointed early telescopes at the stars. There is not enough room here to mention all the achievements of Italian genius Galileo Galilei, but his telescope certainly changed the ways we look at the universe when he discovered the first objects revolving neither around the Sun nor around the Earth - the Galilean moons of Jupiter (In January 1610).

Sources: Wikipedia, Grand Voyage Italy

Galileo and his telescope
Source: biography.com

Astronomy was never the same again after Galileo pointed his telescope at the stars. Looking deeper and deeper into the universe, new constellations were added and soon a new system of organizing the skies arose.
Back to the Renaissance Astronomy Forward to the Age of the Telescope

Back to Star Lore
Start Page

Back to History
Start Page

Back to Space Page

Back to English
Main Page

Back to Start Page