Two years after the official end of its mission, NASA's Cassini spacecraft continues to offer scientists with new information about Saturn.
In a new study, a team analyzed some of the data acquired when the probe made its closest encounter with the gas giant's main rings.
"Getting closer to the rings, getting higher resolution images and spectra, we're starting to get new views, some of the best-ever views of some of the dynamics and evolution of what's going on in Saturn's rings," stated Linda Spilker, a project scientist at NASA's Jet Propulsion Laboratory in California.
A New Look At Saturn's Rings
The new analysis of Cassini's data revealed textures and patterns, some of which present clear evidence of processes that shaped them. Some of these processes involve small moons passing by.
The F ring, in particular, has a number of streaks that are similar in length and direction. Scientists suspected that the pattern was caused by the same impacts from the materials that orbit Saturn.
"This tells us the way the rings look is not just a function of how much material there is," explained Matt Tiscareno, a scientist at the SETI Institute and the lead author of the study. "There has to be something different about the characteristics of the particles, perhaps affecting what happens when two ring particles collide and bounce off each other. And we don't yet know what it is."
Cassini's Visible and Infrared Mapping Spectrometer, meanwhile, revealed the composition of the rings. The A rings were discovered to have weak bands of water ice. Because the area is reflective, scientists initially assumed that the bands of water ice will be stronger and less contaminated.
The latest analysis also ruled out the presence of detectable ammonia ice, methane ice, and organic compounds. The absence of organic compounds was surprising because the spacecraft previously found them flowing from the D ring and into the atmosphere of Saturn.
Cassini To Continue Providing New Discoveries
Jeff Cuzzi of NASA's Ames Research Center, who has been studying the rings of the gas giant since the 70s, claimed that the study, published in Science is only the beginning of the next era of Cassini science. He said that the data collected by the spacecraft throughout its nearly two-decade mission provide new and more interesting puzzles as well as answers to old questions.
The study analyzed data from Cassini's Ring Grazing Orbits in Dec. 2016 and April 2017 as well as its Grand Finale in Sept. 2017, when it plunged itself into Saturn's atmosphere as it runs out of fuel, burning in the process.
