Intriguing patterns seen in Venus' cloud tops
A movie based on images snapped by ESA's Venus Express shows bright and dark cloud bands wind around the poles of Venus in a beautiful sequence.
The spacecraft is tracking the planet from a staggering 66 000 km above the south pole, staring down into the swirling south polar vortex. From this bird's-eye view, half of the planet is in darkness, the 'terminator' marking the dividing line between the day and night sides of the planet.
Intricate features on smaller and smaller scales are revealed as Venus Express dives to just 250 km above the north pole and clouds flood the field of view, before regaining a global perspective as it climbs away from the north pole.
The Venus Monitoring Camera took the images over a period of 18 hours during one of the spacecraft's 24-hour orbits around the planet on 7-8 January last year. It was compiled using public data from the Venus Express data archive.
The camera observes the planet in ultraviolet wavelengths, revealing intriguing patterns in the cloud tops, which ride around the planet about 70 km above the surface.
The observed pattern of bright and dark markings is caused by variations in an unknown absorbing chemical at the Venus cloud tops.
The clouds are driven by extremely strong winds, sweeping around the planet once every four days. By comparison, the planet takes 243 days to complete one rotation about its own axis.
Venus Express has been orbiting the planet since 2006. It carries seven scientific instruments investigating the surface, atmosphere and ionosphere of Venus.