The spacecraft Cassini met its demise about a month ago after NASA made it dive into Saturn. Destroying itself in the planet’s atmosphere, which ended an incredible mission that lasted almost two entire decades. Even though the physical body of Cassini is gone, the information that it previously sent back is still around. Most recently, scientists have discovered a quirk with Saturn’s atmosphere that is leaving researchings puzzled. During Cassini’s trips between Saturn and its rings, the spacecraft’s powerful mass spectrometer picked up a puzzling mix of chemicals that made NASA’s scientists scratch their heads. They speculate that the beautiful rings are shedding.
Cassini’s discovery wasn’t just blind luck. NASA’s earlier missions, dating back to the 1970s provided data that suggested Saturn’s upper atmosphere was littered with ice and scientists believed that it was coming off the planet’s rings. In an effort to test that theory, Cassini checked it out for itself, finding not water but methane and potentially carbon monoxide. Other unidentified molecules were also detected, and scientists are still trying to isolate what exactly they could be.
These chemicals are greater towards the planet’s equator, which points to the possibility that the material is raining down on Saturn from its own rings. What is puzzling scientists is what is the process by which the particles depart from the rings and find their way to the planet’s atmosphere. Mark Perry of Johns Hopkins University Applied Physics Laboratory explains:
“We have a lot of work to do to understand how they are getting in there. None of the models predict this.”
Back in 2013, Cassini sent a picture to NASA which showed a “bump” on the edge of one of the rings. It was brighter than everything around it. Essentially, what they determined was that the rings actually gave birth to moons. This is in line with the French Moon Theory, which holds that “Saturn long ago had a much more massive ring system capable of giving birth to larger moons. As the moons formed near the edge, they depleted the rings and evolved, so the ones that formed earliest are the largest and the farthest out. The mass of the ring system that produced them has been getting smaller with time.” Is that what this is? Or could possibly lead to?
But there’s another theory. During Cassini’s final days, it was zooming along at more than 30 km per second. Which is four times faster than the mass spectrometer was designed to withstand. So could this just be a case of Cassini being too rough for the sensitive planet? At this time, scientists aren’t sure exactly what is causing this, as Perry suggests. This leads me to wonder if NASA killed Cassini too soon? Or are there plans for another mission to Saturn another time?
Space exploration continues to be important. Especially when it teaches us some pretty incredible things about what is around us in the universe. At times, however, it can feel like an episode of Star Trek. That being said, the information that NASA receives from the space missions like Cassini is vitally important to understand what is around us.