Los Angelenos, it could be worse: Astronomers studying Venus have watched a haze much like city smog spread to cover nearly an entire hemisphere of the planet in just a few days, before disappearing.
The photos snapped here are from the Venus Express probe, which has made just over 600 orbits since reaching the planet nearly two years ago.
Last July, it watched an odd bright haze (as viewed in the ultraviolet light spectrum) in the southern hemisphere suddenly brighten and dim, move towards the equatorial regions and then fall back. While much of the planet appears to be a featureless, unchanging globe in visible light, this shows that dynamic chemical processes are at work in the atmosphere, researchers say.
Beyond the jump are more pictures, showing the progress of the haze over several days. The top image was taken on July 8, 2007.
Researchers believe the cause to be an upwelling of the water vapor and sulfur dioxide particles that are usually suspended below the cloud layer. When they broke into the sunlight, chemical reactions began, breaking the molecules apart and recombining them as a haze of sulphuric acid particles.
The process is similar to what happens with smog over large cities, said Dmitri Titov, Venus Express Science Coordinator at the Max Plank
Institute in Germany.
But why is this happening in the first place? The team says they're not sure caused the upwelling of water vapor and sulfur dioxide.
They're also looking for the cause of the dark striations on these images, which represent some as-yet-unknown chemical that absorbs ultraviolet radiation. So stay tuned...
Above: July 24, 2007
Above: July 27, 2007
Above: July 28, 2007
Above: July 30, 2007
The light and dark of Venus[ESA]
(Images: Successive days of Venus' Southern Hemisphere. Credit: ESA/ MPS/DLR/IDA)
