are enormous clouds of ammonia (a substance used in cleaning fluids) and methane (a flammable gas found in swamps and oil wells), as well as other chemical compounds. The chemicals have cooled, formed ice crystals, and metamorphosed into the clouds seen here. The light bands or zones represent high-altitude, low-temperature clouds floating at the top of rising high-pressure areas. The dark bands or belts are low- altitude, high-temperature clouds descending into low-pressure regions. Although the clouds in this image are made up of ammonia, methane, and other compounds, Jupiter’s atmosphere actually consists mostly of hydrogen and helium, the lightest elements.