I daresay they are more like what we should call volcanic clouds.

Do you see how they keep changing?
That's what's bothered our astronomers.

Look at that big one yonder a bit to the north, going from brown to red.

I suppose that's something like the famous red spot which they have been puzzling about.

What do you make of it ?" "Well," said Zaidie, looking up from her telescope, "it's quite certain that the glare must come from underneath.