An Eye On The Weather — On Venus

The European Space Agency reports the Venus Express has revealed a planet of extraordinarily changeable and extremely large scale weather. Bright hazes appear in a matter of days. They reach from the south pole to the low southern latitudes and disappear just as quickly. Such ‘global weather‘, unlike anything on Earth, has given scientists a new mystery to solve. The cloud-covered world of Venus is all but a featureless, unchangeable globe at visible wavelengths of light. Switch to the ultraviolet and the planet reveals a truly dynamic nature. Transient dark and bright markings stripe the planet, indicating regions where solar ultraviolet radiation is absorbed or reflected, respectively. Venus Express watches the behaviour of the planet’s atmosphere with its Venus Monitoring Camera (VMC). Such global weather suggests that fast dynamical, chemical and microphysical processes are at work on the planet. During these episodes, the brightness of the southern polar latitudes increased by about a third and faded just as quickly, as sulphuric acid particles coagulate.