Cool image time! The image to the right, cropped to post here, is part of one of the closest and highest resolution images that Cassini has yet taken of Saturn’s rings. The image was taken in January during one of the spacecraft’s ring grazing orbits, and has a resolution of 2,300 feet per pixel. And yet, as noted by the Cassini science team, “Even at this level of detail, it is still not fine enough to resolve the individual particles that make up the ring.”
In prepping the image, all I did was crop it to show the closest rings. I purposely did not reduce its resolution, so that you can see that no individual particles are visible. The rings of Saturn are truly made up of billions of small objects, behaving in many ways like liquid floating in the gravity well of Saturn. If you don’t believe me, download the full image and zoom in on it as much as you like. All you will see are pixels.
The fundamental science question therefore is not how Saturn’s rings behave (though this is certainly important and quite fascinating) but why did those rings end up the way they are. No other planet has rings anything like Saturn’s in their density and make-up. Why? Are Saturn’s rings a normal process that only occurs for short times around planets, which is why only Saturn has these types of rings at present? Or is it a rare event, so rare that we happen to be very lucky to see such a thing at all?
Even more important, Saturn’s rings and their behavior are likely linked closely to the same phenomenon that describe the formation of planets around a star. The more we can learn about why these rings exist, the more we will learn about why planets exist, both here circling the Sun as well as around stars everywhere else.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
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