On Sept. 15, 2017, after 13 years in orbit, Cassini approached Saturn for the final time and plunged into the planet's atmosphere.
Even during its final moments, the spacecraft was still gathering data about the enigmatic gas giant. Scientists from NASA have just now started releasing the analysis of data from its grand finale.
Cassini's Long Journey
Cassini was launched by NASA, the European Space Agency, and Italy's space agency in October 1997 and reached Saturn in 2004. A year later, it successfully landed a probe called Huygens on Titan.
During over a decade of exploration, it was able to study some of the planet's many moons and discovered potentially habitable environments, including the liquid water in the subsurface of Enceladus that can potentially support life.
Running low on fuel and to avoid accidentally contaminating one of the moons of Saturn with any bacteria from Earth, NASA decided to plunge Cassini into the atmosphere of the planet it studied for more than 10 years.
Cassini's Grand Finale
One of the key takeaways from the recently released analysis from Cassini's grand finale was the dust grains about a nanometer in size raining down into Saturn's atmosphere. Scientists estimate that between 4,800 and 45,000 kilograms of particles and gases are falling from the inner rings to the upper atmosphere of the gas giant every second.
While most of these particles fall directly into the atmosphere, some become electrically charged and end up in the planet's magnetic field lines in a phenomenon called "ring rain." These particles are made up of water and small amounts of other materials such as silicates and complex organic molecules.
Another major discovery is Saturn's rather puzzling magnetic field. Cassini has provided scientists with a new measurement of the planet's magnetic field, confirming that, unlike Earth, the magnetic field of Saturn perfectly aligns with its rotation.
NASA says scientists will continue to analyze the remaining data sent by the spacecraft's instruments for the next couple of years.