Astronomy Picture of the Day

Explanation: Jupiter's thick atmosphere is striped by wind-driven cloud bands that remain fixed in latitude - dark coloured bands are known as belts while light coloured bands are zones. At Jupiter's belt-zone boundaries the shearing wind velocities can reach nearly 300 miles per hour. Near infrared images recently returned by the Galileo Spacecraft were mapped to visible colours in this close-up of a belt-zone boundary near the gas giant's equator. The colour mapping reveals different layers, lower clouds are bluish, higher ones pinkish. The smallest features seen are tens of miles across.