Night Lightning on Jupiter . ... Credit Copyright: The Galileo Project , NASA Explanation: Why is there lightning on Jupiter ? ... To create lightning , charges must first separate inside a cloud. ... Many astronomers theorize that Jovian lightning is also created in clouds containing water ice. ... The bright flashes appear to originate in active regions at the level where water clouds would exist, and illuminate an even lower cloud level containing ammonia . ... NASA Official: Jay Norris. ...