June 18th-20th, 2025
On the occasion of the 400th anniversary of the birth of Giovanni Domenico Cassini, born in Perinaldo (Italy) on 8 June 1625, we would like to remember the most illustrious astronomer of his time: his studies had such an impact beyond national borders that in 1669 the Sun King, Louis XIV, asked him to found the Observatoire de Paris, the first modern astronomical observatory.
The main Italian cultural and research Institutions associated with Cassini – the University of Bologna, the National Institute for Astrophysics, the Academy of Sciences of the Institute of Bologna – together with local administration, supported the request to the Ministry of Culture to create a national committee to celebrate the great astronomer in 2025.
Among the activities promoted by the committee is the international conference we are presenting, which aims to give historians and scientists the opportunity to discuss and analyse in-depth the Cassini era, a historical period marked by a great acceleration in the progress of science and astronomy. New ideas, new instruments, new methods, including the open exchange of information and cooperation between scientists even across national borders, made it possible to make important discoveries about the Solar System – the whole universe as it was then known. The process was faster than in the past, and all this was surrounded by a general cultural context of great ferment.
The conference will be accompanied by a series of events aimed at student and general public, culminating in a day dedicated to observing the sun from Piazza Maggiore in Bologna, with guided visits to the Great Meridian of San Petronio on 21 June. The summer solstice of 2025 will be 370 years after the day on which Cassini invited professors of mathematics and philosophy and other curios citizen to witness the start of the construction of his “eliometro”.
Topics for discussion will include:
- Cassini and his era: society, scientists and authority,
- From the Republic of Letters to the European scientific network of Academies,
- Cassini's cosmos: visions of the Solar System from the seventeenth century up today,
- Observations of Mars, Jupiter, Saturn,
- Cassini, Halley and the comets,
- Cassini and the telescopes of the seventeenth century,
- Cassini between heaven and earth: the Pope's engineer and the King's cartographer,
- Cassini in Bologna: the ephemerides and the great meridian line in San Petronio,
- Cassini at the court of the Sun King.
