“I don’t know why I go to extremes.” —Jupiter (probably)    The planet is home to fierce jet streams, polar cyclones bigger than Australia, the most powerful aurora and harshest radiation belts in the solar system - and we’re just scratching the surface.     Data from Juno helped develop a new model to better understand the fast-moving jet stream that encircles Jupiter’s cyclone-festooned north pole. Juno took the first-ever temperature measurement of the cap of Jupiter’s atmosphere above the north pole: it’s about 52ºF (11ºC) cooler than its surroundings and is encircled by winds exceeding 100 mph (161 kph). Unlike hurricanes on Earth, which typically occur in isolation and at lower latitudes, Jupiter’s massive northern polar cyclone and the eight cyclones that encircle it are confined to the polar region. Jupiter’s cyclones cluster together while approaching the pole, and their motion slows as they begin interacting with neighboring cyclones.    Image description: An enhanced-colo...