Wide belts of the atmosphere are changing color, hotspots are vanishing and reappearing, and clouds are gathering over one part of Jupiter while dissipating over another, NASA's Jet Propulsion Laboratory in Pasadena, Calif., reported Wednesday.
"The changes we're seeing in Jupiter are global in scale," senior JPL research scientist Glenn Orton said. "We've seen some of these before, but never with modern instrumentation to clue us in on what's going on.
"Other changes haven't been seen in decades, and some regions have never been in the state they're appearing in now," he said. "At the same time, we've never seen so many things striking Jupiter. Right now, we're trying to figure out why this is all happening."
While Jupiter's own atmosphere has been roiled by changes, a number of objects have crashed into the giant planet, creating fireballs visible to amateur Jupiter watchers on Earth, he said.
Three of impacts have been observed since 2010, with the latest in September.
"It does appear that Jupiter is taking an unusual beating over the last few years, but we expect that this apparent increase has more to do with an increasing cadre of skilled amateur astronomers training their telescopes on Jupiter and helping scientists keep a closer eye on our biggest planet," Orton said.