14 September 1712 - Death of Giovanni Cassini, he made the first accurate measurement of the distance from the Earth to the Sun

Giovanni Domenico Cassani, son of Jacopo Cassini and Julia Crovesi, was born in Perinaldo, Italy, on 8 June 1625.

He studied at the Jesuit College in Genoa and Bologna and, from an early age, showed great interest in mathematics, poetry, and astrology. It was his interest in the latter that led him to study the universe, eventually focusing exclusively on astronomy.

Cassini was an astronomer at the Panzano Observatory from 1648 to 1669, where he completed his education. In 1650, the senate of Bologna appointed him head of astronomy at the university. There he taught astronomy and mathematics.

In 1655 he determined the inclination of the Earth's orbit, the diameter of the Sun, and the refraction of light in the atmosphere, publishing his results in 1662. In addition, the telescopes of Eustachio Divini of Rome and Giuseppe Campani provided him with great discoveries: he determined the rotation of Jupiter in 1965 and calculated the rotation of Venus and Mars.

In 1669 he moved to France and took over the direction of the Paris Observatory at the express request of King Louis XIV. There, between 1671 and 1674, he discovered four satellites of Saturn: Iapetus, Rhea, Thetis, and Dione. In 1675 he observed a discontinuity that is now known as the Cassini division. Also in 1673, the year he was granted French citizenship, he made the first precise measurement of the Earth's distance from the Sun.

In 1690 he was the first to see the differential rotation of Jupiter and the first to study the zodiacal light and understand that it is not a meteorological but an astronomical phenomenon.

Cassini's career was very prolific, and he also excelled as an engineer. He went on to work for Pope Clement IX on fortifications, river management, and the flooding of the Po River and how to prevent it. His work as a surveyor in France would be continued by his sons and grandsons.

In recognition of the great role he played in the world of astronomy, a crater on the moon is named after him, as well as a crater on Mars and the asteroid 24101 Cassini, 7 km in diameter, which is in the asteroid belt and was discovered in 1999.

Cassini went blind in 1711 and finally died on 14 September 1712 in Paris at the age of 87.