Surprises at Saturn
Cassini found out much about the ringed planet, but experts weren't expecting these
Cassini's final plunge
To ensure that Cassini didn't contaminate any of Saturn's moons, the mission ended its 13 years of service via a controlled entry into the gas giant's atmosphere. It's here that the spacecraft broke up as it plunged through the layers and layers of gas, succumbing to the planet's pressure.
More going on between its rings
It might look empty between its rings and its surface, but there's much more going on here than initially suspected – that's because of a connection between the upper atmosphere and the gas giant's crowning feature: streaming electric currents that flow between the rings and the outer atmosphere. However, it's not clear what's causing them or why they're there; that's something that the Cassini mission will help us to figure out. And that's not all – it's thought that there's also a belt of radiation that's coming from trapped energetic particles between the rings and the planet.
Strangely flat magnetic field
Unlike the other outer planets in our Solar System that have tilted magnetic fields, Saturn's is perfectly straight and, according to our understanding of how these fields are made, this shouldn't be possible: according to the Cassini team it's the tilt that keeps the magnetic field from dying away. However, before the spacecraft plunged into the atmosphere it discovered that this wasn't the case – in fact, it could suggest that the ringed giant is generating its magnetic field in a different way, perhaps with many onion-like layers of flowing particles instead of a single zone.
Saturn’s rings rain material
Saturn's innermost rings rain the equivalent of 1,800 cars per minute in tiny particles onto its atmosphere – unsurprisingly, it's called ring rain. Cassini uncovered that around Saturn's equator this rain deposits some 45,000 kilograms of ice, dust and gas every second, and it could mean that the rings are disappearing much more quickly than we initially thought. And, because the rain is made up of ammonia, nitrogen, methane and other such complex organic particles, it could be that the Saturn's top layers are being affected chemically.
Cassini team members at NASA’s Jet Propulsion Laboratory receive data from thefirst of Cassini’s Grand Finale flybys