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NASA’s Cassini reveals the full glory of Saturn’s rings

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They’re even more spectacular in the close-up detail it delivers.


“This then, I thought, as I looked round about me, is the representation of history. It requires a falsification of perspective. We, the survivors, see everything from above, see everything at once, and still we do not know how it was.” –W.G. Sebald

Saturn is remarkable in a number of ways; among all the planets we know of, it’s the least dense, and also the only one with a spectacularly visible set of rings.

Image credit: NASA/JPL/Space Science Institute.

Composed of icy, dust-like material, these rings aren’t solid, but made up of particles that pass each other, sticking together briefly and torn apart by tidal forces.

Image credit: NASA/JPL/Space Science Institute.

Snowballs and planetesimals coalesce, only to be torn apart by tidal forces exerted by Saturn and its passing moons.

Image credit: NASA/JPL/Space Science Institute.

Gaps in the inner rings are caused by the gravitational presence of moons themselves, while many outer rings — like Saturn’s E-ring — are actuallycaused by emission from moons themselves.

Image credit: NASA/JPL/Space Science Institute, of Saturn’s E-ring, with Enceladus as the brightest spot.

The main rings extend from 7,000 km to 80,000 km above Saturn’s equator: larger than Saturn’s radius.

Image credit: NASA / JPL-Caltech / Space Science Institute, via http://www.ciclops.org/view/7699/The-Day-the-Earth-Smiled?js=1.

The ring system itself is just 10 meters to 1 kilometer thick all the way through, and is likely as old as Saturn itself.

Images credit: NASA/JPL/Space Science Institute, via http://photojournal.jpl.nasa.gov/catalog/PIA07874.

Composed of 99.9% water-ice, the ring system has thousands of thin gaps, and was thicker and more varied in the past.

Image credit: NASA/JPL/Space Science Institute.

The once-rocky material has coalesced into moons, but the watery rings will remain for as long as our Solar System exists.


Mostly Mute Monday tells the story of a single astronomical phenomenon or object in pictures and other visuals, with no more than 200 words of text.

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