Why does Jupiter have cloud bands?

The light stripes are called zones, while the dark ones are belts. These bands are driven by powerful atmospheric flows that travel in opposite directions at speeds reaching some 540 kilometres (340 miles) per hour.

We know from observations that the temperature and composition of the zones differ from the belts. Zones are colder, which corresponds to gas upwellings, and are rich in frozen ammonia, hence their colour. Belts are hotter, which means that the gas flow is downwelling.

Two main ideas compete to describe their origin. First that they are generated by deep internal convection, a process where the motion of the gas transfers heat. Since Jupiter’s atmosphere and interior are connected, the zonal flows would extend substantially into the conducting hydrogen core. Second is that they’re surface phenomena, primarily maintained by the temperature difference between the zones and belts. Recent data suggests the former, which if confirmed would be an amazing revelation.

Dr Mohamed Zaghoo, research associate at the University of Rochester, New York

The zones and bands of Jupiter have been a mystery to astronomers ever since the telescope was first invented