Saturn. The breathtakingly beautiful gaseous sphere is encompassed by elegant rings of light and dark bands which continue to capture our imaginations .With its angelic rings and almost perfect hexagonal storms, and volcanoes that spit fire and ice, no wonder people associated it with the mystic. In various myths Saturn is associated with bad luck, melancholy and even destruction, so I suppose it’s fitting that the first mission to Saturn would be beautifully destroyed there.
The reason for that was much more scientific. Cassini discovered that Saturn’s moons had liquid water beneath its surface. It was one of those discoveries that led to a paradigm shift, because no one expected liquid water at such a huge distance from the source of heat(the sun) . If a new form of life had potential to evolve independently there, the scientist didn’t want to contaminate it with microbes from earth, hence the kamikaze. It was at a time before Trump, where the nuking of our planet and the resulting extinction of our own species wasn’t a thing, and we didn’t have to worry about furthering our lineage yet.
Titan is covered by seas of liquid methane and ethane and Enceladus nesting a subsurface saltwater ocean. Enceladus is a tiny miracle, its diameter only 505 km which is no larger than the length of the UK, but nonetheless is a strong contender as a habitable moon. Cassini revealed that there was something pushing against Saturn’s magnetosphere, and that turned out to be a jet stream of ice particles with simple organic chemicals and water, projecting hundreds of miles into space
The iconic rings of Saturn are a glorious spectacle, seemingly smooth discs of ice making their way around Saturn; Few sights in the solar system can be compared to their beauty. They consist of particles that can be as small as a grain of sand or as colossal as large mountains, casting extraordinary shadows over the surface of Saturn. In fact, Cassini gained information about the size and composition of the ring particles by studying these shadows. The accretion on the rings gives scientists hints about how the solar system was formed.
New features like propellers and spokes which were poorly understood were brought into the light. Spokes are radial characteristics of the rings, which rotate along with them and are believed to be caused by electrostatic charges lifting particles to heights of around 16,000 kilometers. Propellers are features produced by the gravitational effect of moonlets, which create wave-like ripples in the rings.
One of the stranger discoveries was a ‘glitch’ named Peggy, after the scientist’s mother in law (we’re not sure if this is a compliment) . Peggy is only known by the disturbance it causes in Saturn’s otherwise smooth ‘A ring’. Its own form hasn’t been observed. Scientist believe analysis of data will reveal that Peggy is a moon in formation.
So why spend 4 billion to crash dive a probe 7.8 billion km away after 20 years? ‘For the aesthetic’ doesn’t seem to cover it. Well to quote Carl Sagan : “Exploration is in our nature. We began as wanderers, and we are wanderers still. We have lingered long enough on the shores of the cosmic ocean.” Our lives mirror Cassini. We yearn for exploration, held by a riveting curiosity about what’s out there, until finally becoming part of the earth again. For a few fortunate people, it could be another planet.
After providing us with stunning postcards of this exotic destination (ring surfing, anyone?) and letters of data and digits from its long space cruise, Cassini gracefully slipped into the heart of Saturn and its embrace, where it will remain forevermore (or at least until the sun gobbles up everything).