We have to move to Italy to find the first speculation about the content of that forbidden zone. In the last book of Cicero's Republic, the author imagines a dream of Scipio Aemilianus, at the siege of Carthage, in 149 B.C. His grandfather, the great Scipio Africanus, appears in front of him and somehow takes him to a place in the Milky Way. In young Scipio's own words: "As I gazed out from where I stood, the whole prospect looked marvelously beautiful. There were stars we never see from this place, and they were larger than we could possibly have imagined."
Cicero's Republic was lost in the Middle
with the exception of Scipio's Dream, which was preserved in a
written in Rome by Macrobius, at the close of the fourth
book Macrobius leaves no doubt that Scipio is speaking of the
the South Pole which were never seen from the Roman world. This
was widely read in Medieval circles. It probably was the
Dante Alighieri (thirteenth century), who in his Divine
at the beginning of the Purgatory (Canto I), says these
| I' mi volsi a man destra, e puosi mente
a l'altro polo, e vidi quattro stelle
non viste mai fuor ch'a la prima gente.
Goder pareva 'l ciel di lor fiammelle:
oh settentrional vedovo sito,
poi che privato se' di mirar quelle!
| I turned me to the right
to the other pole, and saw four stars,
never seen save by the first people.
The heavens appeared to rejoice in their flamelets.
O widowed northern region,
since thou art deprived of beholding these!
Surprisingly, this statement turned out to be absolutely true! In fact, there are exactly four first magnitude stars (α and β Centauri, and α and β Crucis) that had been observed by the Greek, but which could no longer be seen from the Northern Mediterranean in Dante's time. Where did he get his information from? Was it an ancient tradition that did not reach our times? Some Arab traveller passed him the word? Or was he inspired by the four cardinal virtues, as is read in some footnotes of Dante's work? Those four first magnitude stars were probably part of the star catalogue included in the Almagest of Ptolemy, which became available in Europe (in Latin translations) a century before Dante's birth. But it is unlikely that this was his source, because those stars, if present, are grossly misplaced and only one of them (α Centauri) is labeled as first magnitude.
There is another astronomical reference in
which is not as well known. It is also relevant to our story, as
see later. The sighting of the four stars had happened just
After a long day had passed, it was dark once more. The
takes then place between Virgil and the author (Canto VIII):
| E 'l duca mio: «Figliuol, che là
E io a lui: «A quelle tre facelle
di che 'l polo di qua tutto quanto arde».
Ond'elli a me: «Le quattro chiare stelle
che vedevi staman, son di là basse,
e queste son salite ov'eran quelle».
| And my Leader: "Son, at
gazing up there?"
And I to him: " At those three torches
with which the pole on this side is all aflame."
And he to me: "The four bright stars
which thou sawest this morning are low on the other side,
and these are risen where those were."
Four bright stars and three 'torches' near the south pole! Did they have any influence in later generations? Let us continue our story.
Our next information about the southern stars comes from none the less than Amerigo Vespucci, the same explorer that gave his name to the New World. In a letter recounting a voyage that probably took place in 1499, he claims to have followed the coast of Brazil up to a point 6° south of the Equator. He had searched in vain for the south pole star, but found none closer than 10° to the pole (in fact, 3rd. magnitude b Hydri was just at that distance in the fifteenth century). Then he remembers the words of Dante in the Purgatory, about the four bright stars. After quoting the lines in full, he says: "It is my belief that in those verses the poet wants to describe with the four stars the other pole of the firmament, and up to now I have no doubts about the truth of his statement, because I noticed four stars in the shape of an almond which had little movement." Later in the letter we are told that these observations were done in July and August. At that time of the year, Crux is already past the meridian, in an inclined position, and is not easily recognizable as a cross. Is the almond identical to the Southern Cross? We cannot say for sure.
In a later letter Amerigo Vespucci tells us
another voyage, in which he had a much better opportunity to
southern stars. In his narrative he says that they attained a
of 50° south. He dedicates several paragraphs and a couple
to the southern sky. He starts by saying that he has noticed
stars as bright as Venus or Jupiter. Then he mentions that he
also three 'Canopes' in those regions, two of them bright and
obscure. The region near the pole is described with these words:
are 3 stars with the shape of an orthogonal triangle, turning in
with a semidiameter of 9.5°." Then he refers to the
the bright Canopes and provides a rough drawing of it, together
3 stars forming the triangle. Two other stars come after this
at a distance of 12.5° from the pole. They are followed by
bright Canope. His description continues with the words: "After
other 6 stars, the most beautiful and bright among all the
eighth sphere, the semidiameter of their circumference measuring
Together with them moves a black Canope of immense magnitude.
seen in the Milky Way, and when crossing the meridian they show
Though it may be questionable to identify the 2 bright Canopes with the Magellanic Clouds, there is little doubt that the previous figure represents the Southern Cross followed by β and α Centauri. The distance to the pole, the fact that in no other part of the sky you will find such a concentration of first magnitude stars and, above all, the placing of the black Canope exactly where the Coal Sack is, all argue in favor of the proposed identification. There are some other considerations, however, which work against that statement. There are scholars that think that this letter is a fake and that Vespucci never reached those southern latitudes. His geographical descriptions are as vague as those of the bright Canopes. His other astronomical observations do not add up to his credibility. For instance, he says that twice the whole crew has seen the rainbow near midnight, or that in those places the New Moon is visible on the same day of its conjunction with the Sun. Another possibility is that he wrote the letter several years after the voyage, at a time when he did not have with him his notes any more, which, as he himself says, had been left with the king of Portugal.
Let us go back to our story. What do we have up to now? Descriptions of a southern wain, an almond, a triangle, Canopes, but not a single word about a cross. In fact none of these asterisms are recorded in the first 'modern' star atlas, an engraving by the German artist Albrecht Dürer, dated 1515. In this atlas the area of the sky not visible in Hellenistic times is still left empty, roughly a circle somewhat eccentric to the sixteenth century southern pole.
Pigafetta kept a diary throughout the voyage. In it we are told about the giant inhabitants of the Patagonia and the language they use, the 3 months of navigation across the Pacific Ocean without seeing any inhabited land, the death of their commander in the Philippines, and finally the long way home sailing west around the tip of Africa. But Pigafetta also had time to write about the stars. In a backwards recollection placed in his diary after the crossing of the Pacific, he says "The Antarctic pole has not the same stars as the Arctic. Near the pole there can be seen many small stars clustered together, in the like of two nebulae not far apart from each other and somewhat obscure, in the middle of which there are two very big stars, not very bright and with little movement." It is my guess that the two nebulae are a reference to the Magellanic clouds, while the two big but not very bright stars may be the globular cluster 47 Tucanae, near the Small cloud, and the Tarantula nebula in the Large one.
After a digression related to the deviation of the compass from the true North, he proceeds by telling us that in those seas they saw a cross of five very bright stars, right to the west and very well adjusted the one with the other. His exact words in Italian are: "Quando èramo in questo golfo vedessimo una croce de cinque stelle lucidissime, dritto al ponente e sono giustissime una con l'altra." A cross at last, described by a fairly reliable witness! Obviously it should be our Southern Cross, what else? But can we be sure? Let us cross check his description.
Magellan moved out of the strait on November 28, 1520. By the end of January they would have left the Southern Hemisphere. Pigafetta's cross was probably seen in December or early January. The nights in those latitudes were short. In fact, when going through the strait they never had complete darkness. Is it possible that they saw the Southern Cross placed 'right to the west'? You can perform the exercise yourself, with any planetarium software available in the market. To your surprise you will find that at that time our Cross was placed in the southeastern sky. You will also notice that though there are five conspicuous stars in the Cross, only 3 of them (α, β and γ) are really bright, with magnitudes between 1.0 and 1.6. The fourth (δ) is a 3rd. magnitude star, and the fifth (ε) is more than half a magnitude dimmer. And definitely only the first four fit into the pattern of a cross, as can easily be seen in the banner of Australia.
What if the words 'dritto al ponente' really meant something like 'pointing right to the west'? While slowly turning clockwise around the pole, there will be a moment when the Cross is seen horizontal, and its long arm (γ —> α) pointing due west. We should also be prepared to accept that 'sono giustissime una con l'altra' only means that the five stars were packed in a small region of the sky, without any implication about their relative positions. Whatever be the case, there is little doubt that most Europeans heard of the Cross for the first time when they read the narrative of that incredible circumnavigation around the world.
It had not been Pigafetta, however, the first European to write about the Cross. Not surprisingly it was another Italian, as all the main characters of my story up to this moment. While the Spanish and Portuguese were unveiling the 'terra incognita' of the ancient maps, it seems that the Italians were the real discoverers of the southern skies. The name of this gentleman was Andrea Corsali. He was a Florentine diplomat that somehow managed to be on board a Portuguese ship, sent by king Manuel to interchange ambassadors with the mythical Prester John, the Christian king of Ethiopia, which for many centuries had remained completely isolated from their brethren in faith.
In a letter sent to Guiliano de Medici, written in India on January
The information provided by Corsali is much more accurate than all the references we have mentioned before, and leaves no doubt about the identification. I even consider possible that Pigafetta had seen Corsali's letter before writing the final version of his diary, taking part of his information from him. I am not saying that he had not seen the Cross, but perhaps he had not taken notes about it during the voyage, and his recollections some years later were somewhat confused.
Considering that Pigafetta's diary was completed at the end of 1524, and that it circulated in manuscript form only, it is almost sure that Fernández de Oviedo, who had started writing his History several years before, had known of the Cross independently of Corsali or Pigafetta.
Another book written a few years later, in 1538, implies that the Southern Cross could be easily recognized by the sailors of the Southern Seas. In the Cosmografía of the Spanish Pedro de Medina, the first navigation manual ever written, the Cross is used in the same way as Polaris in the Northern hemisphere for finding the latitude at sea, . Medina's words are: "It is necessary to know that the signs to recognize the Antarctic Pole are four stars disposed as a cross. These stars are not one of the signs of the Zodiaque, nor any of the other 35 constellations of the sky. Their name is Crucero. One of these four stars is called the head, another the foot, and the two others the arms. To know which is which, you must know that the one at the foot is greater than the others. When the cross is standing upright, the one at the foot is closer to the horizon, and its distance to the Antarctic Pole is 30 degrees."
To put an end to this part of the narrative, let me add a final
not for its documentary value but because of its literary beauty.
taken from the Lusiadas, the great Portuguese epic poem
by Camoens in 1572. The following verses probably refer to the
|"Já descoberto tínhamos diante,
Lá no novo Hemisfério, nova estrela,
Não vista de outra gente, que ignorante
Alguns tempos esteve incerta dela.
Vimos a parte menos rutilante,
E, por falta de estrelas, menos bela,
Do Pólo fixo, onde ainda se não sabe
Que outra terra comece, ou mar acabe."
|"We had already discovered
in that new hemisphere, a new star,
unseen by other people, ignorant
of its presence for a long time.
We saw the part less brilliant and,
for lack of stars, less beautiful,
of the fixed Pole, where yet it is not known
if another land begins, or the sea comes to an end."
We have seen how the Southern Cross became known to most sailors around the world and many learned men in Europe. That should be the end of the story, but really it is not. A most intriguing part is still ahead. I refer to the painful and devious way in which the knowledge of the Southern skies came to the attention of the scientific community. Believe it or not, European astronomers seem to have had a very scanty knowledge of the Cross for most of the century. Scholars were too busy rediscovering antiquity, to waste their time with the real world. They gave more consideration to a phrase in Aristotle or Ptolemy, than to any report from the newly discovered lands. If in 1610 they were to deny the reality of the spots on the Sun or the moons of Jupiter, visible through Galileo's telescope, why should they believe in stars they had never seen?
The first known description of the starry heavens is a Greek poem named Phaenomena, written in 270 B.C. by Aratus of Soli. It includes a thorough description of the constellations known to the
Other literary descriptions followed. It was only a matter of time for shapes of the constellations to be shown in graphical form. The best known representation of that kind that has reached our times is the Farnese Atlas, dated 200 B.C. It is a celestial globe on the shoulders of the giant Atlas, with the mythological constellations embossed on its surface. By the way, this is the reason why up to this day any representation of the celestial or terrestrial globe is called an atlas. The poor giant did not labor in vain!
Some manuscripts have come to us from the middle ages with representations of the constellations. The beautifully decorated figures, however, have almost no scientific value. The individual stars are not depicted, or if present have no relation to actual stars. When in the sixteenth century the importance of stars for navigation became apparent, those representations were of no use. The observation of the stars could provide an accurate value for the latitude and, in some cases, a rough knowledge of the longitude. Without a good star chart, it was not easy for navigators to find out the right star in the sky. Believe it or not, Columbus, the Admiral of the Ocean Sea, made a mistake in the identification of Polaris, and computed the latitude of the Antilles as that of New York!
We have already mentioned the first modern star atlas of Albrecht Dürer.
The imagination of the mappers of the skies did not end there. Another much stranger constellation found also a place in the previously uncharted area. It was pointed to me by my friend Ray Harris, an expert in ancient star charts. In fact it was he who brought all this matter to my attention, and who provided most of the information related to this part of my story. This constellation is a human figure placed near the Southern Pole, with the very appropriate name of Polophylax, which in Greek means the Guardian of the Pole. I think its purpose is to provide a southern counterpart of the constellation Arctophylax (also known as Bootes), which translates as the Guardian of the Bears.
Let us recapitulate. At the beginning of the era of discoveries the knowledge of our globe and of the skies was derived almost entirely from the two classic books of Ptolemy: the Geography and the Almagest. The first contained a rather inaccurate description of less than a quarter of the surface of the Earth, just including Southern and Central Europe, Africa north of the Sahara and a part of Western and Southern Asia. The Almagest, instead, was already capable of showing all the stars of any importance visible to the naked eye, covering more than 85% of the whole sky.
A century and a half later, geography had enlarged dramatically the knowledge of the Earth. The terrestrial globes and charts showed entirely new continents and huge oceans undreamt of before. Astronomy, on the contrary, had provided no input at all, and the only additions that celestial cartographers could make were a few misplaced or imaginary constellations based on ambiguous reports of navigators written many decades before.
Cartographers turned to astronomy for help. In the case of the stars visible from Europe, they required a new star catalogue with less errors than those in the Almagest, and with more accurate positions. For the southern stars, they needed measurements to replace the purely descriptive accounts received from navigators. The first requirement was met by the work of the greatest astronomer of the period, Tycho Brahe, who since 1575 had been observing with unprecedented accuracy the stars visible from his native Denmark. But there was no Tycho in the southern lands.
An enterprising Dutch found a typical business solution. If there is no southern Tycho, let us make one! We have met this man already. He is the same Petrus Plancius who had placed (or misplaced) the Cross and the Southern Triangle for the first time on a celestial globe, as well as a few other new northern constellations. When the first Dutch expedition set sail for the East Indies in 1595, Plancius asked its pilot, Pietr Keyser, to make 'state of the art' observations of the southern stars. Keyser, who observed from Madagascar and Sumatra, died in the journey. His work was compiled by Frederik de Houtman, the chief of the expedition, and sent back to Plancius. Houtman made additional and improved observations in a second voyage, in 1598, which he published as a catalogue when he came back, some years later.
With the new observations in his hand, Plancius distributed the previously uncharted area in 12 new constellations. He also recognized the true position of the Cross. The new constellations appeared for the first time in a globe designed by Jodocus Hondius, in 1598, and in a later one issued in 1603 by Willem Blaeu, a former collaborator of Tycho Brahe. It was also in 1603 when the Bavarian Johannes Bayer published his famous star charts, introducing for the first time the usage of Greek letters to label the brightest stars of each constellation.
In Bayers' atlas the sky was divided in 48 individual plates, one for each of the traditional constellations, plus an additional plate that grouped the twelve new ones introduced by Plancius.
The explanation seems to be that Bayer is not using for the Cross
new positions recorded by the Dutch, but those of the venerable
In fact, most of the stars shown in this part of Bayer's chart are
recognizable in a modern atlas. Using the astronomical program
Project Pluto, with the optional Almagest Star Catalogue
me, I have prepared a chart with the real and Almagest stars for
1600. Both its orientation and the grid are for ecliptical
to match Bayer's chart. The 2 bright stars on the left are α
and β Centauri. The actual cross are
the four colored stars to the left of the label 'Cru'. The
are depicted as white disks with pink diagonal spokes. Bayer
up his cross with the 4 leftmost Almagest stars of the 5 seen in
part of my chart, though his positions are only approximate.
The first document I have seen showing the Cross in about its proper place and with the right orientation is a celestial globe edited in 1613 by Jodocus Hondius Junior and Adrian Vaen. Here the Cross is labeled as a separate constellation. The label is written in Latin, meaning: "The Spanish Cruzero, but the Centaur's feet in Ptolemy."
The fact that the Cross was born with a Spanish name is not irrelevant. It is another argument in favor of the popular origin of this constellation, in contrast with all the other modern 'Latin' constellations which were artificial constructions of one scientist or the other. This puts our Southern Cross in the same category as the traditional constellations of the Greeks, most of which can trace their pedigree to the Chaldeans and the Sumerians. The Cross turns out to be the only 'natural' constellation of our times.
This brings us to our last subject: the religious significance of the Southern Cross. There can be no doubt that for those Spanish and Portuguese sailors thousands of miles from home, the sight of the Cross up in the sky must have been a source of comfort amidst their sufferings and fears. In those days of miracles and wonders, it was all very natural that the most precious symbol of their Faith preceded them in the conquering of the new worlds in the name of the Cross.
The difference between the Christian Cross of the South and the northern pagan constellations was notorious. In the seventeenth century there was even an attempt to Christianize the whole skies,
Had the Cross any influence in the history of the Southern
We all know that the conquistadors seem to have made more use of
than of the cross in the colonization of those new lands. Yet the
that emerged from that process were in no way void of the moral
represented by the Cross, and we cannot say that the nightly
of those 4 stars, placed in the most beautiful part of the sky,
a positive influence in the hearts of those sailors, priests,
farmers and workers of every type that lived and still live in the
After all, who can deny that this hemisphere turned out to be much
peaceful than the old one, and that either by their own efforts or
divine protection the Southern people have managed to keep their
the world out of most of the wars that have plagued mankind in the
and already in the twenty first centuries!