On the night of Oct. 15, 1997, a six-ton spacecraft was launched from Cape Canaveral Air Force Station in Florida where it began its quest to Saturn. This spacecraft, called the Cassini-Huygens, or Cassini, was a collaboration between NASA, the European Space Agency (ESA) and the Italian Space Agency (ASI), to send the probe to Saturn for further studies into its rings and even its largest moon, Titan. This space mission was the fourth to visit Saturn and the first to enter into its orbit.
Named after astronomers Giovanni Cassini and Christiaan Huygens, the Cassini-Huygens spacecraft was actively traveling for 20 years. Cassini had orbited Saturn for 13 years. On July 1, 2004, Cassini entered Saturn’s orbit to study the planet and its system. While the spacecraft was composed of the Huygens and Cassini modules, the two modules had traveled together, until the Huygens section separated from the complex on Dec. 25, 2004. The Huygens module successfully landed by parachute on Titan by Jan. 14, 2005. This was the first spacecraft landing on a moon other than our own, and it was the first ever accomplished in the outer Solar System.
While radio waves took 83 minutes to travel from Saturn to Earth, Cassini captured its delayed data to the last minute while spontaneously burning in Saturn’s atmosphere.
The objectives of Cassini involved determining three- dimensional structure and dynamic behavior of Saturn’s rings, measuring the magnetosphere’s structure and dynamic behavior and studying Titan’s surface on a regional scale.
“This is the final chapter of an amazing mission, but it’s also a new beginning,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate at NASA Headquarters in Washington. “Cassini’s discovery of ocean worlds at Titan and Enceladus changed everything, shaking our views to the core about surprising places to search for potential life beyond Earth.”
In Cassini’s operations, data from eight of its scientific instruments was beamed back to Earth. Scientists will be occupied for years with information of 635 gigabytes of images and sensor readings. Elements of this planet, its magnetosphere, rings and moon will reveal information for scientific discoveries.
More specifically Cassini revealed that Saturn’s atmosphere changes colors with the seasons. Additionally, Saturn’s rings pulse as ring particles clump together and shatter and ripple in the gravitational force of the passing moons. Cassini also revealed that Titan, Saturn’s largest moon, is covered with lakes. They are comprised not of water but with methane and other simple hydrocarbons. Titan’s landscape is constructed of complex organic molecules.
During Cassini’s mission, the probe caught a glitch along the smooth edge of Saturn’s ring that has never been discovered before. This mysterious disturbance, named Peggy, was first sighted in early 2013. It was observed by Cassini-project veteran Carl Murray of Queen Mary University of London. After the team’s questions about Peggy expanded, such as what it was, how it formed, and where it came from, his team began tracking this object.
Murray and his colleagues revealed that this glitch may have been caused by an object em- bedded in the rings, although the object is unknown. “All we can do is track the glitch, Murray said.
After further studies of the size of this disturbance, Murray concluded that it could not possibly be a solid moon, since this would result in a total disruption of the ring. Instead, he hypothesized that it must be a dense cloud of dust and debris creating a proto-moon that is not quite an independent object.
As this mysterious object drifts inward and outward from Saturn, it causes the glitch of the rings to change speeds. Murray’s team of scientists were able to measure the orbital parameters of the object.
However, tracking this object resulted in a wide range of uncertainty where Peggy would appear and disappear in the images captured by Cassini. Fortunately, Murray and his team still have hope in discovering more about Peggy with the help of 13 years worth of data to reveal the planet.