Do we have good quality, close-up imagery of the composition of Saturn's rings?

All of the images I can find of Saturn’s rings are either: not close enough to show their actual composition, or ‘artist’s conception’ of what we think they might be made of.

Have none of the probes sent to study Saturn taken a close look at the rings? (I mean, close enough to see whether they are made of dust, or chunks the size of aircraft carriers?

If not, is there some technical reason why not? (risk of losing the probe in a collision, perhaps), or it it just not an interesting enough thing to want to take a close look at?

How about this, or this? You can see the grain.

That third one is wonderful.

In the first, second and last of those images (certainly the first), the grain looks more like a limitation of the imaging resolution than the actual, physical granularity of the subject.
In the third, you can see formations and their shadows, but I believe these are undulating waves of particles, not singular objects.

None of these pictures is anything like detailed, even if we are seeing real grain - the particles could be Mickey Mouse-shaped, and we still wouldn’t know.

Here’s a higher-res version linked to from that third link. They look like clouds.

ETA: Yeah, none of those are going to show the actual grains. I believe they can determine the sizes of the ring particles from other means.

Wikipedia says the main ring particles range from 1 cm to 10 meters.

What are your grounds for thinking that? There are other Cassini photographs that look extremely sharp, not grainy at all. These aren’t photos taken with old-fashioned silver halide film, you know.

If the particle size really is tens of metres at the largest, then any picture that displays curvature in the rings can’t possibly also show the grain.

Well aware of that.

In that first image, the grain/noise has horizontal and vertical linear components (relative to the frame, not the subject) - it looks like (as you say) not a photo, but more like a faxed image (which is actually quite similar to what it is).

Would it even be physically possible to have good quality images by your definition?

I would imagine that the distance between particles of similar size would be much much larger than their diameter, so it might not be common to have more than one particle of the same size visible in the same frame. Any image that is close enough to resolve individual particles is going to be mostly empty space.

Yes. Send a probe into the rings.

It might have to be a disposable one - like Huygens.

But it sounds like you already knew that never happened. We don’t do that for the much larger asteroids either, to my knowledge. Space probes are expensive so why destroy one just to get a close-up when a fly-by can deliver lots of good information on many things? Trying to bash a probe into a dust grain is not a useful way for scientists to spend money. I’m just having trouble trying to figure out what your underlying question really was. Your responses to the answers indicated that you had a different question in mind.

We have sent a probe to orbit Saturn. It’s plausible it could safely get close enough to the rings to photograph 10 meter grains.

When Cassini was inbound on it’s capture orbit to Saturn, it passed through the rings. The required orbit required it. Before passing through one of the gaps they rotated the craft so that the main antenna went first. Not much protection but every little bit helps. As far as I know, there were no hits on the spacecraft as it went through the rings. They did get very close at least once!

More or less. I’m really asking two things:
Have any of our existing probes got close enough - if not, why not? Safety? Practicality? More important priorities?

and

Why, specifically, have we not sent a single-use probe to take a close look? Cost? Not interesting enough a prospect? What?

No, this was in the OP.

And, when Cassini did pass through the ring, we confirmed that they’re filled with fine dust. It’s not a picture but there is a sound recording of dust particle impacts as measured by one of Cassini’s instruments.

Those are fascinating pictures, and a fascinating audio file.

So the rings are entirely made up of rubble (up to 10 meters in diameter, apparently), and the fact that they look like they have solid structure (and solid sheets of ice where giant icicles hang or giant spikes stand up) is just an artifact of the distance of the probe taking pictures, right?

So then, I have a question which I think is along the same lines as the OP: what would it look like to dive through the rings like Cassini did? Would it look solid like it does in pictures, and then gradually break up into a bunch of smaller particles with black space behind them? Or maybe it would be like a light fog, where you can see it from far off, but then when you’re in it, you can’t see the fog that’s right around you?

The A and B rings make up the vast majority of the area of the brightly lit inner rings. They’re the two wide, brightly lit rings in this picture, separated by a distinct black gap (the outer A ring itself has a tiny gap visible in the picture). They’re basically what you think of when you picture “the rings of Saturn” in your head.

While it appears most of the mass of the rings is composed of particles in the 1 cm to 10 m range, most of what we see are much smaller particles, more like smoke or fog than hail or boulders; the A and B rings are about 5 to 30 meters thick, so whatever they’re made of only has that distance to block most of the light shining through the rings. If you pack 1-cm ice balls close enough to block 50-90% of the sunlight in only 30 meters, you’ll end up with a total mass many orders of magnitude greater than the total mass of the rings.

So if you imagine a bank of fog only 5-100 m deep but so thick that it actually casts a shadow, that ought to be similar to what the rings look like close-up.

See, all of this makes me wonder why we haven’t sent a probe right in there. It’s a chance to examine an extraterrestrial environment without having to land on a planet. Saturn’s rings apparently have a sparse atmosphere of their own - I cant help wondering if there might be some really interesting surprises in there.

I would guess it’s a case of the science / new learnings that could be gained from such a mission aren’t seen as being worth the cost, especially in an era when NASA is struggling with funding (and the definition of its mission, in general).