Giovanni Domenico Cassini was a famous Italian astronomer and mathematician born in 1625. He is best known for his work on the planet Saturn, where he discovered its largest moon, Titan, and observed the planet's rings. Cassini's detailed studies helped improve our understanding of the solar system. In addition to his discoveries, Cassini made significant contributions to the field of celestial mechanics. He developed methods for calculating the orbits of planets and comets. His work laid the foundation for future astronomers and scientists, making him a key figure in the history of astronomy until his death in 1712.