As part of the Cassini-Huygens mission conducted jointly by NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI). The Cassini orbiter made several groundbreaking discoveries. Since its mission began when it left Earth atop a Titan IV rocket on October 15, 1997.
A journey of nearly two decades and almost 5 billion miles will come to a dramatic end next Friday. Cold, alone, and very far from home, the Cassini orbiter will take a long last look at the pale blue dot whence it sprang and finish its 294th and final orbit of Saturn by nosing over and dropping through the gas giant’s atmosphere in one final. Fatal contribution to mankind’s understanding of the planetary system in which we live.
The hexagonal cloud pattern at Saturn’s North Pole was discovered by Voyager in 1981studied in greater detail by Cassini. Over the course of its observation, the hexagon changed color, going from a sea green to a golden brown. The craft also took thermal infrared images and video of the hexagon.
Though no definitive answers have been established for why the strange cloud formation exists and persists. Cassini gathered a significant quantity of invaluable data on the oddity. Possibly paving the way for future scientists to discover an explanation for the phenomenon.
Saturn has been famous for its rings. Galileo first observed them in 1610 and has drawn the attention of astronomers in the centuries since. However, the complex structure of the rings makes up-close observations of them critical for learning more about them. In the spring of 2005, Cassini began an experiment to measure the size distribution of the rings’ particles by passing radio waves through the rings and measuring the nature and degree of distortion the particles cause.
In addition to experiments using radio waves, Cassini took hundreds of the most detailed photos of Saturn’s rings ever produced, leading to the discovery of previously-unknown ringlets.
Cassini made several passes near Saturn’s moon, Enceladus, and gathered a great deal of data that rocketed the moon to the top of the list of possible life-bearing celestial bodies. In its first passes in 2005, the craft detected anomalies in Enceladus’ magnetic field that strongly suggested the presence of an atmosphere, and discerned via other measurements that the atmosphere consisted mostly of ionized water. The probe also identified ice geysers on the moon’s South Pole.
Nine years later, the probe found even more water on the planet, detecting a significant salty ocean beneath its surface that likely covered the entire body beneath its rocky crust. With this discovery, scientists declared that the distant moon is one of the most likely places in the entire solar system to find microbial life other than Earth.
Seven New Moons
Ranging in diameter from 300 m to 7.6 km, the Cassini mission discovered the following moons:
In addition to these moons, Cassini discovered a “propeller moonlet” in one of Saturn’s rings and an object. Soon become a moon in another ring. Fourteen significant bodies were discovered circling Saturn by Earth-based observation. Since Christiaan Huygens discovered Titan with a homemade telescope in 1655.
Voyager discovered another five when it flew by in 1980 and 1981, but Cassini raised the bar by detecting another seven distinct orbiting bodies between 2004 and 2009.