by Jesse Murray
On Friday, September 15, the Cassini spacecraft came to a spectacular end as it made a controlled entry into the atmosphere of Saturn and burned up. This event marked the end of the almost twenty year-long Cassini-Huygens mission, a collaboration between NASA, the European Space Agency and the Italian Space Agency. Launched in October of 1997, Cassini entered its orbit around Saturn in July of 2004. Since that time, the mission radically improved our understanding of the Saturn system and has been successful beyond expectations.
According to NASA, in December of 2004, Cassini released the Huygens module, which landed by parachute on Titan. Upon landing, the Huygens module collected important data including temperature, brightness, methane relative humidity and pressure on the surface of Titan. In June of 2004, the Cassini spacecraft made its only flyby of the moon Phoebe and took close up images that led scientists to believe that a large amount of water ice exists under the immediate surface of Phoebe. Cassini also made many close flybys of the moon Enceladus, even passing within 50km of the moon’s surface. The spacecraft flew through the plumes of its geysers, detecting water, carbon dioxide and various hydrocarbons using its mass spectrometer. These and other observations led NASA to report evidence of a large salty internal ocean of liquid water in the moon, which dramatically increased the probability that the moon holds life. Cassini also performed a series of radio occultation experiments to measure the macro and micro structure of Saturn’s rings. The spacecraft flew behind the ring plane of Saturn and transmitted radio waves through the ring that were received on Earth and analyzed for phase shift and frequency. Finally, Cassini entered its Grand Finale in April this year. It made a series of close Saturn passes and then an entry into Saturn’s atmosphere to destroy the spacecraft and prevent biological contamination of any of Saturn’s moons.
All in all, the Cassini-Huygens mission discovered 6 named moons, collected 635 GB of data, made 162 flybys, completed 294 orbits and led to 3,948 published scientific papers.