Renaissance Astronomy

In Western Spain, during the Renaissance, close in time to when Columbus led his first expedition to the New World with the sponsorship of the Spanish queen, the astrology department at a university founded in 1218 CE, painted the first planetarium on the ceiling of the university's library. 

It was based upon the configuration of stars and planets over a few days in August of 1475, presumably from notes compiled at least five years before the painting began, in an alignment that will recur in late August this year. As a new paper about this early artist's rendition of an astronomy observation explains:

[I]t was painted by the famous Salamancan painter Fernando Gallego (1440-1507), who belonged to the Hispano-Flemish Gothic School. However, the “Sky of Salamanca”, both for its subject matter, analogous to that of certain Italian works of the same period, and for its grandiose proportions — it is a quarter of a sphere 8.70 metres in diameter —, can be considered . . . . a precedent of the Renaissance style.

The abstract of a new paper, and it citation, are as follows: 

"El Cielo de Salamanca" ("The Sky of Salamanca") is a quarter-sphere-shaped vault 8.70 metres in diameter. It was painted sometime between 1480 and 1493 and shows five zodiacal constellations, three boreal and six austral. The Sun and Mercury are also represented. It formed part of a three times larger vault depicting the 48 Ptolemaic constellations and the rest of the planets known at the time. This was a splendid work of art that covered the ceiling of the first library of the University of Salamanca, one of the oldest in Europe having obtained its royal charter in 1218. But it was also a pioneering scientific work: a planetarium used to teach astronomy, the first of its kind in the history of Astronomy that has come down to us in the preserved part that we now call "The Sky of Salamanca". 

We describe the scientific context surrounding the chair of Astrology founded around 1460 at the University of Salamanca, which led to the production of this unique scientific work of art and to the flourishing of Astronomy in Salamanca. We analyse the possible dates compatible with it, showing that they are extremely infrequent. In the period of 1100 years from 1200 to 2300 that we studied there are only 23 years that have feasible days. We conclude that the information contained in "El Cielo de Salamanca" is not sufficient to assign it to a specific date but rather to an interval of several days that circumstantial evidence seems to place in August 1475. The same configuration of the sky will be observable, for the first time in 141 years, from the 22nd to the 25th of August 2022. The next occasion to observe it live will be in 2060.

Carlos Tejero Prieto, "Astronomy at the University of Salamanca at the end of the 15th century. What "El Cielo de Salamanca" tells us" arXiv:2202.10442 (February 21, 2022).

As an aside, the paper notes that at around the same time that this planetarium was painted, an astronomy text that would become a mainstay for Iberian oceanic navigators in the 16th century was translated for the chair of this faculty from Hebrew (written by a relative of his) to Spanish.