i'm sorry if this is not a forum for this but, i don't know if it's a error in WWT or a dirt on the telescopes lens or a extraterrestial circular ship, but i just zoomed in on jupiter and there is a black circle on it (it's moving, to the right) it's pretty weird i have screenshot's(but i have no idea how to include them, i'll upload them to my website and i'll post the link here) you can try zooming on jupiter and checking if that black circle is there, it's moving