Saturn: King of the Rings and Moons

This Planet Endlessly Fascinates Viewers

When I was a little kid, I found a book in the Time-Life series about planets. I could barely understand most of the words, but the pictures spoke loudly. In particular, one image of a strange-looking planet with a ring around it caught my imagination. It seemed like the most alien thing, the embodiment of alien worlds and far-off places. I later learned that was the planet Saturn. Wow!  I couldn’t even think of how such a thing could exist. And I had SO many questions about it. How a planet with rings around it. How did it come about?  How far away was it? Could we live on it?  Would we ever get to explore it?

Later, of course, I found out much more about Saturn and its rings and moons. The Voyager 2 mission flyby of Saturn was the first one I ever covered as a science writer, and I was like that little kid all over again. I still have the images I carefully collected during the press conferences, and somewhere in my archives, I have a tape of me interviewing some of the project scientists.  It was my first “up close” encounter with the Saturn People and the planet that so fascinated me as a kid.

Saturn was the first REALLY alien world I “discovered” on my own, and so I still look at it with some mixture of that old awe and childlike wonder. This is why the constant stream of images from the Cassini Solstice Mission is such a delight. They are, like the images from the rovers and orbiters at Mars (my other most favorite planet), providing an almost real-time look at a distant world. The rings, in particular, still boggle my mind. They stretch out from Saturn so far that if you plopped the planet between Earth and the Moon, they’d cover nearly 3/4 of the distance between the two. Yet, this expansive set of rings is less than a mile thick! The rings are made of countless particles of ice and dust, and they’re threaded by the orbits of small moons.

Of course, there’s more to Saturn than just the rings. There are dozens of moons, but Titan and Enceladus are in the news a lot. Titan is not just another icy world. It has an active atmosphere (rain and winds), and appears to have lakes and streams of liquid methane running across its surface. That alone makes it a tempting target for further exploration. The Cassini Huygens lander provided us a short look at the surface, and if you didn’t know it was all ethane and methane, you’d swear you were in a polar landscape.

Without a doubt, the moon Enceladus is the other tantalizing world in this system. It sprays geysers of water ice particles out to space, from reservoirs of salty fluid deep below the frozen surface. Recently Cassini scientists suggested that there are cracks running across the surface and down into the icy crust that connect the outer surface to the warmer material interior of Enceladus. Something (like the flexing of tidal heating due to the gravitational pull of Saturn as Enceladus orbits the planet) is pressurizing the water and forcing it up to the surface and out into the geysers you see here.

The Cassini mission celebrates ten years of Saturn exploration this year. During its time orbiting within the Saturnian system, this spacecraft has been sending back a steady stream of images and data about what was once a mysterious gas giant and its odd rings. I’d like to think that Galileo, who first described the appearance of those rings through his telescope as “ears” would be grinning and laughing to see what we’ve discovered at Saturn. Certainly the mission’s namesake, 17th century astronomer Giovanni Domenico Cassini, who discovered four of Saturn’s moons and made note of the ring divisions, would be enthralled with what we now know about his favorite target.  In addition, Dutch astronomer Christiaan Huygens, who also studied Saturn’s rings and discovered Titan, would be joining his compatriots in joyful celebration of what Saturn is and what we’ve learned.

If you’d like to explore Saturn through Cassini’s eyes, check out the Cassini Solstice Mission website. It’s full of images, news releases, educational materials, and much more!