Did you know that Giovanni Domenico Cassini was born today in 1625? As an astronomer, he helped to establish Johannes Kepler’s theory that the Earth orbits the Sun. Later he calculated the distance between Earth and the planet Mars, which helped estimate the size of the solar system. Cassini also discovered 4 of the 62 known moons of Saturn and what appeared to be a gap in the rings around Saturn, which is now known as the Cassini Division. The Cassini space probe, which was launched in 1997 to study Saturn, is named after him.
We hope that you have a perceptive day at school today. Remember to think kind thoughts, use kind words, and do kind things. We Love You.
Giovanni Domenico Cassini was also a mathematician and engineer. As an engineer, Cassini helped to build and maintain fortifications and structures to help manage rivers and flooding.
The names of the 4 moons Cassini discovered are Iapetus, Rhea, Tethys, and Dione. He initially called them Sidera Lodociea, or the “Stars of Louis”. One of the moons, Iapetus, varied in brightness while it was observed. Cassini attributed that to the moon being made of materials with different dark and lightness.
Giovanni Domenico Cassini shares the credit for discovering the Great Red Spot on Jupiter with Robert Hooke.
Giovanni Domenico Cassini started a project to create a topographic map of France. His son, Jacques Cassini, also worked on the project. Cesar-Francois Cassini de Thury, Giovanni Domenico Cassini’s grandson completed the project in 1789. It was the first topographical map of an entire country.