1 or 2 bands (maybe 3) and the other "permanent features" (e.g. Cassini division).
It's kind of like Jupiter, Saturn is divided into belts and zones from the equatorial region, the tropical region, the temperate region, and the polar region mirrored on both northern and southern hemispheres. Each has a belt (darker) or a zone (lighter) or both.
: https://britastro.or...8-4 Foulkes.jpg
: On Saturn you should see the (North or South) equatorial belts (NEB/SEB) pretty well, maybe the temperate belt, and certainly the darker northern polar region (NPR). So, that's two belts if you're lucky, seeing is good, and the planet is cooperating, and a polar region. These belts can be broad or narrow. The NEB tends to be pretty broad and normally darker along the southern edge is shares with the equatorial zone. Sometimes the northern edge of the NEB darkens and you might see a third "belt" there. At times, a fourth belt might be seen along the equator called the equatorial belt (EB). The EB, northern NEB (really part of the NEB) and the Northern Temperate belt can be very low contrast and may or may not be easily seen. It depends on Saturn's weather and often on Saturn's tilt.
So, potentially one might see the EB, NEB, NTB, and the NPR. The NEB and the NPR seem to have the best chance of being seen, so you may only see 1 belt and the polar region when Saturn is low, when seeing is not cooperating, using a small aperture, poor contrast, or the activity in Saturn's atmosphere is not conducive. My guess is, most times we'll see the NEB and a very weak NTB along with the polar region. That was my view back in 2011/2012 apparition. The NEB was broad and fairly solid and the NTB a little further north was barely visible.
: You should see the equatorial zone directly below the rings easily enough. You might make out the northern tropical zone (NTrZ) between the NEB and the NTB and the northern temperate zone (NTZ) below the polar hood. So, that's potentially 3 zones: equatorial (EZ), tropical (NTrZ), and temperate (NTZ).
Thomas seems to show a stronger divided NEB in his sketch above, but not the very weak and low contrast tropical band (NTB) further north. He also shows the equatorial zone well, and probably the tropical zone, too. Sasa shows the same with a hint of the NTB. So, that's really 2 belts that looks like 3. Also, Sasa shows the obvious EZ and probably the NTrZ. If he saw hints of the NTB, then it was likely divided by the NTrZ between the NTZ (gets confusing sometimes) and the northern polar region. David Gray shows all of them.
So, I'd expect on most nights in a modest aperture we'll see the EZ topped by the NEB bordered by the NTrZ which might seem to merge with the NTZ as a very broad zone and all of that capped off by the polar region. However, on a good night and with luck, the NTrZ and NTZ might be split by the very weak NTB, making 2 belts and 3 zones
- and the polar region - visible in a modest aperture. David Gray (Correct me if I am wrong or not using enough acronyms to describe it) shows the equatorial belt, the northern equatorial belt, and the northern temperate belt. But, he does show some variation in the northern edge of the NEB and in the southern edge of the NPR. Both of which appear to be different belts. He also clearly shows the equatorial zone (split by the equatorial belt), the tropical zone, and the temperate zone. Edit
: The NEBn (north equatorial belt north) and NNTB (north north temperate belt)...just like Jupiter.
So, does that answer the question?
Probably 2 belts maybe three (depending) along with 2 or 3 zones and a polar region most of the time are likely to be visible in a modest aperture when seeing is good.
: The rings, IMO, is where it's at. Starting from the inner rings, we may be able to see the Crepe ring as kind of eerily transparent. Inside that is the B ring with some of it's features. It appears darker on the inner most edge and has a brighter ringlet bordering the Cassini division. That darker inner edge is not the "spokes" we hear of, not to my knowledge. Then working outward, of course Cassini division is seen between the B and A rings. Outside of that is the A ring with it's features starting with another bright ringlet bordering just outside the Cassini division. The a little further out, the Enke minimum *might* be seen near the middle of the A ring. This is not the Enke Gap, it's merely a portion of the A ring with lower surface brightness. Forget the Enke gap in the apertures we're talking about, seeing that requires larger aperture and good seeing.
That's my opinion and experience, but I have not observed Saturn since the 2012 apparition when Saturn was well placed in excellent seeing not far from the tropical zenith. Things change and some have keen eyes for such things, the proper magnification may play a role, at least good optics with good contrast and the rest of it.
Edited by Asbytec, 20 May 2019 - 08:24 AM.