The Cassini spacecraft has spent a grand total of 13 years studying both Saturn and its moons and, when it finally ran out of fuel, the team behind it decided that Cassini’s swan song would be one to remember – they designed a trajectory that would send the spacecraft through Saturn’s rings before it would burn up in its atmosphere.
The spacecraft was pushed to its limits, way beyond what the team had thought possible, because initially, it had not been designed with such a dive in mind. The data Cassini collected during that time revealed many interesting things for the scientists.
One of them is the product of the measurements coming in from the ‘ring rain’ – a trickle of tiny particles that fall from the innermost ring of the planet, down towards the upper atmosphere – hydrogen and helium.
What Cassini found was more material through – the instruments on board the spacecraft spotted, in addition to the expected hydrogen and helium, also carbon monoxide, methane, nitrogen and some remains of organic molecules which they could not identify.
Other instruments on board suggested that the downpour was also peppered with water ice and silicate particles. The downpour seemed to be triggered by those particles interacting with the highest levels of the planet’s atmosphere.
You might ask why this is important and what it might mean. Well, the compounds in the ring have proven to be way more diverse than expected and this means that new hypotheses will have to be considered about how Saturn has formed and evolved.
“Almost everything going on in that region turned out to be a surprise. That was the importance of going there, to explore a place we’d never been before. And the expedition really paid off — the data is tremendously exciting.”
Since the scientists have no idea, at the moment where most of the material in the ring’s composition is coming from, the information they got from Cassini raises even more questions than it answers. As expected, our Solar System still keeps its mysteries.