tulika wrote:

Thanks Jan Owen for those images, that whole site is very useful.
It kind of makes sense now, main culprit is just light and air
pollution.

No, neither light pollution nor air pollution has anything to do with
it.
If anything, air pollution (within reason) makes planetary views
better.

The issue is *seeing* -- atmospheric stability. Do you know how views
of distant objects waver when you view them over a hot parking lot, or
through the exhaust from a furnace? That's bad seeing, in extreme form.
But seeing has to be *really* terrible to affect naked-eye views.

At 120X through a telescope, however, even the most miniscule
thermal instability will degrade an image. That's why the seeing is
often *better* on hazy nights than on crystal-clear nights. When it's
sparklingly clear in a rural area, the ground radiates heat like crazy
to the night sky, and the temperature plummets, causing all sorts
of instability. In a city, however, the air pollution blocks much of
that radiation, the temperature doesn't fall as fast, and the seeing
is better.

Seeing is also generally poor in the northern U.S., where the jet
stream often passes directly overhead, and good in the southern
U.S., where the weather tends to stay stable and boring for long
periods at a time.

With a high-quality, well-collimated telescope of any size or design,
seeing is the limiting factor in how good the planets will look.

Having said that, poor collimation is an even more common source
of bad high-power images. Put another way, good collimation is
absolutely essential for planetary viewing. I've seen a mushy,
whitish view of Jupiter change into a lovely set of blue and brown
whorls and streaks with a 1/8 turn of one collimation screw.

- Tony Flanders