I’d be willing to bet that it’s an “ozone hole” caused by “global warming.” Of course, the NASA guys and a bunch of other kooks on this planet are currently wringing their hands over some shiny clouds they’ve been seeing on this planet. Could be aliens I guess.
CHANGES ON JUPITER: "On July 30th, it was evident that there is rapid evolution of Jupiter's impact debris cloud," reports amateur astronomer Raffaello Lena of Rome, Italy. "It is becoming very elongated." A polar projection shows the extent of the debris: