Born on June 8, 1625 in Perinaldo, Republic of Genova, this Italian?French man was the first to come up with an estimation of the Solar System?s Dimension. He was also the one to observe the four moons of Saturn and together with Robert Hooke, the discovery of the Great Red Spot on the planet, Jupiter. These are just a few of the contributions of Giovanni Domenico Cassini to the field of Astronomy. It is also worth noting that he was also known as Jean ? Dominique Cassini when he changed nationality to French.

Proud parents, Giacomo Casssini and Julia Crovesi had Giovanni. In the later years, most especially when he began studying, it was his mother?s brother who took care of him and raised him. This science genius became an Astronomer at Panzano Observatory and a professor at the University of Bologna then became the director of the observatory. He moved from Italy to Paris, that is why his nationality is Italian from 1625 ? 1673 and a French from 1673 ? 1722. His observation of Sidera Lodoicea or the four moons of Saturn, including lapetus has exposed and make him known in Astronomy.

In recognition to this observation, it is known as Cassini Regio. The Cassini Division was also named after him as he is able to discover the four rings of Saturn. In 1690, he also was the one to observe the differential rotation within Jupiter?s atmosphere. He and another colleague, Jean Richer observed the planet Mars and they computed its distance from Earth. Also, he made measurements of longitude by the use of an alternative clock ? eclipses of Jupiter?s satellites. On the other hand, it was King Louis the IV of France who helped him establish the Paris Observatory.

Eventually, he was hired by Pope Clement IX to attend to Engineering concerns such as river management, fortifications; however when he was asked to accept Holy Orders, he declined as what he wanted was to focus on his profession as an Astronomer. Furthermore, he was the proponent of the Cassini oval, a plane curve, sets of points which denote that the product of the two distances two fixed points is constant.

It is also interesting to note that Cassini was married and had two sons and a daughter. He and his wife, Genevieve Delaistre were married in 1674. Had he not moved to France, he may not have met his wife. His life came to an end on September 14, 1712 due to an illness. In honor of Cassini, the ESA-NASA of the Mission Cassini to Saturn was named after him.